Caterpillarchallenger
Caterpillar MT735
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar MT735 is a rubber-track row-crop tractor in the original Challenger MT700 "A"-series lineup (MT735/MT745/MT755/MT765), built by Caterpillar at its Jackson, Minnesota plant from roughly 2001 through 2006. It runs a Caterpillar C9, an 8.8 L inline-six turbodiesel rated at 235 hp gross, 185 PTO hp, and 178 hp drawbar, paired with a 16-speed powershift transmission (30-speed creeper optional) and Caterpillar's Mobil-trac rubber-belt undercarriage riding on tri-bogie mid-rollers. Operating weight runs around 12,784 kg (28,185 lb), climbing with ballast, track width, and attached implements. Production MT735 units share a single AKN serial prefix across the run, and the tractor was offered in standard row-crop and various track-width/ballast configurations to sit below the higher-horsepower MT745, MT755, and MT765 stablemates in the same platform.
Within the MT700 A-series, the MT735 sat at the entry-horsepower end below the MT745, MT755, and MT765. Those three siblings were later refreshed into MT745B/755B/765B variants, but Caterpillar never issued an MT735B: the smallest A-series model was effectively phased out rather than carried into the next generation. When AGCO later took over the Challenger brand, the segment continued under the MT700B/C/D series with AGCO Power engines at markedly higher horsepower, so nothing in the MT735's own model line was a direct one-for-one replacement. That gap is part of what keeps the MT735 relevant in the used and parts market today: it is the lowest-cost entry point into genuine Cat-built Mobil-trac technology, drawing buyers who want rubber-track flotation and drawbar pull without the price or complexity of the larger A-series tractors, and its parts commonality with the C9 engine family and shared MT700 undercarriage keeps salvage and aftermarket support relatively accessible despite the model's age.
Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.
Caterpillar MT735 specifications
Engine
| Engine model | Caterpillar C9 inline-6 diesel |
| Displacement | 8.8 L (537 cu in) |
| Cylinders | 6 |
| Bore x stroke | 112 x 149 mm (4.41 x 5.87 in) |
| Compression ratio | 16.0:1 |
| Gross engine power | 175 kW (235 hp) at 2100 rpm |
| PTO power, rated | 138 kW (185 hp) |
| Drawbar power, rated | 133 kW (178 hp) |
| PTO power, test | 150-161 kW (201-216 hp); figure varies across test results. |
| Drawbar power, test | about 120 kW (160 hp) |
| Emissions | Not published for this generation. This engine predates the Tier III ACERT-rated C9 used in the later MT700C-series tractors and is not Tier III certified. |
Weights
| Operating weight, base | 12,784 kg (28,185 lb) |
| Operating weight, ballasted (max) | about 15,000 kg (33,070 lb) with full ballast; treat as approximate, varies by configuration |
| Ground pressure | Not published for this model |
Dimensions
| Wheelbase (Mobil-trac) | 2438 mm (96 in) |
| Track gauge, standard | 1524-2235 mm (60-88 in), infinitely adjustable |
| Track gauge, wide | 2032-3048 mm (80-120 in), infinitely adjustable |
| Track gauge, ultra-wide | 3048-4064 mm (120-160 in), infinitely adjustable |
| Overall length, width, height, ground clearance | Not published in available dealer literature for this generation - verify with your dealer or the operator's manual |
Performance
| Transmission | Powershift, 16 forward x 4 reverse; 30-speed creeper transmission optional |
| Maximum travel speed | 39.6-40 km/h (24.6-25 mph); figure varies slightly by test/configuration. |
| Steering | Electro-hydraulic differential steering, crawler-track drive |
| Brakes | Wet-disc service brakes |
| Rear PTO | Independent, 1000 rpm, 1-3/4 in shaft |
| Drawbar pull, test (max) | about 11,884 kg (26,200 lb) recorded in factory test data |
| 3-point hitch lift capacity | Category III, 7,257 kg (16,000 lb) |
Service capacities (summary)
| Fuel tank, standard | 447 L (118 US gal) |
| Fuel tank, optional | up to 787 L (208 US gal), depending on rear-axle/gauge configuration |
| Hydraulic system flow | 164.6 L/min (43.5 gpm) standard pump, 200 bar (2900 psi) max system pressure, 4 to 6 remote valves |
| Engine oil capacity | Not published for this model - verify with your dealer or operator's manual |
| Cooling system capacity | Not published for this model - verify with your dealer or operator's manual |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
MT735 fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with filter) | Not published in the accessible service literature for this exact tractor. Engine is the Caterpillar 8.8 L (537 cu in) turbocharged diesel inline-six (112 x 149 mm bore/stroke, 16.0:1 compression, rated 2100 rpm, 235 hp gross) — confirm sump volume against the dipstick or dealer parts book. | Cat DEO (Diesel Engine Oil). Select viscosity grade by ambient temperature per the standard Caterpillar diesel engine oil cold-weather chart; heavier multigrade for warm climates, lighter multigrade (e.g. synthetic cold-weather blend) for sustained sub-freezing starts. |
| Cooling system | Not published in the accessible service literature for this model. Confirm with a dealer or against the radiator/surge-tank fill marks. | Cat ELC (Extended Life Coolant) or an ELC-compatible extended-life glycol coolant/water mix, per standard Caterpillar diesel cooling-system practice for this engine family. |
| Fuel tank | 118 US gal (446.6 L) on the standard 88 in rear-axle/track-spacing configuration. Wider-gauge axle options (120 in / 160 in) carry a larger 178 US gal (673.7 L) tank, with a 208 US gal (787.3 L) tank listed as optional. A conflicting 91 US gal (345 L) figure also appears for the shared tank across this platform; capacity varies by rear-axle/track configuration — confirm against the fill-cap or tank decal on the specific unit. | |
| Transmission (16-speed powershift, 30-speed creeper option) | Not published in the accessible service literature. On this tractor family the powershift transmission shares its oil circuit with the hydraulic system and final drives rather than carrying an isolated sump; confirm total system fill with the dealer. | Cat TDTO (Transmission/Drive Train Oil) — the multi-compartment fluid Caterpillar specifies to cover powershift transmission, final drive, and hydraulic service together on this class of machine, reducing the number of distinct oils carried. |
| Hydraulic system (implement circuit + track-tension accumulator) | Reservoir volume not published in the accessible service literature. System operates at 2900 psi (200 bar) with 43.5 US gpm (164.6 L/min) total pump flow. The undercarriage track-tensioning cylinder is charged off this same implement hydraulic circuit rather than a separate reservoir; nitrogen accumulator precharge runs 2100-2300 psi. | Cat TDTO, shared with the transmission and final drives on this tractor family. Caterpillar's fluid-compatibility guidance also lists Cat MTO (Multipurpose Tractor Oil) as an approved fluid for Cat/Challenger tractor axle and hydraulic service — use whichever grade is called out on the machine's fluid decal. |
| Final drives (each side) | Not published in the accessible service literature for this model. Each final drive carries its own check/fill point even though the fluid type matches the transmission/hydraulic circuit. | |
| Grease (specification only) | Applied per the multi-point lubrication schedule, not a bulk fluid fill. | Exact grade not confirmed for this model in the accessible service literature. Standard-era Caterpillar practice calls for an NLGI 2 multipurpose EP chassis grease on undercarriage and pivot points — confirm the specified grade on the machine's lubrication chart before use. |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar MT735 maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 4,000 h |
|
| Every 6,000 h |
|
Servicing the MT735 beyond the schedule
Predictive Maintenance & Fluid Analysis
Run S·O·S sampling on the C9's engine oil, transmission/powershift oil, hydraulic oil, and coolant on every drain interval. Watch iron and copper trends in the powershift sample; on this platform they flag clutch pack wear before a shift quality complaint shows up. Track coolant nitrite/pH on the C9 to catch liner cavitation early, since a cracked wet liner is a costly surprise on this engine. Log fuel dilution on oil samples; a rising trend often traces to a leaking injector before it throws a fault.
Corrective & Common Repairs
Common MT735 failure points center on the Mobil-trac undercarriage: worn bogie wheel and idler bearings, track tension cylinder seal leaks, and belt edge-cord separation from field debris. On the powertrain, watch for powershift solenoid and clutch pack wear as hours climb past mid-life, along with final drive seal leaks at the drive sprockets. The C9's turbocharger and injectors are the typical engine-side wear items; boost loss or hard starting usually traces to one of those two before the long block itself.
Overhaul & Rebuild Points
Major overhaul work on the MT735 concentrates on the undercarriage and powertrain rather than the engine block, since the C9 is a comparatively durable design. Expect belt track replacement, idler and mid-roller wheel rebuilds, and drive sprocket segment renewal as the tractor pushes past mid-to-high hours. Powershift transmission rebuilds typically mean new clutch packs and seals; pull the unit for inspection once shift flare or slippage shows up on the monitor. Final drive housings warrant a teardown once gear noise or seal weeping appears.
Seasonal & Environment Servicing
Before spring fieldwork, inspect both rubber belts for winter-storage cracking and check track tension after cold soak, since rubber contracts and can read tight on the gauge. Clean chaff and residue from the engine compartment and radiator core after harvest to prevent trash fires and airflow restriction over winter storage. In freezing regions, verify coolant protection on the C9's cooling system and drain fuel-water separators more often, since ag diesel picks up more condensation through seasonal temperature swings than steady industrial duty.
MT735 common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 1R-0762 | Filter As-Fuel | Fuel system service | Check fitment → |
| 161-1705 | Sensor As-Pressure | Lubrication service | Check fitment → |
| 1R-0716 | Filter As-Engine Oil | Lubrication service | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
MT735 fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| E100 | Engine oil pressure below the normal operating range, sensed by the engine ECM. | Low oil level, worn oil pump, restricted pickup screen, or a faulty oil pressure sensor/wiring. | Stop and check oil level and condition first. Verify sensor wiring and connector, then confirm with a mechanical gauge before deeper dealer diagnosis. |
| E110 | Engine coolant temperature reading outside the normal range (running hot). | Low coolant level, plugged radiator or screens, weak fan drive, or a faulty coolant temperature sensor. | Check coolant level and radiator/screen condition, inspect the fan drive, then have the dealer scan the ECM if the warning returns. |
| E102 | Turbo boost (intake manifold) pressure out of the expected range for engine load. | Dirty air filter, restricted or leaking intake piping, or a turbocharger/wastegate fault. | Check and service the air filter, inspect intake hoses and clamps for leaks, then contact the dealer if the code persists. |
| E94 | Fuel filter/fuel supply pressure restriction detected by the engine ECM. | Clogged fuel filter, low fuel level, water or debris in the fuel, or a weak transfer (priming) pump. | Check fuel level, inspect and change the filter if due, verify the priming pump and its fuse, then contact the dealer. |
| E9131 | Electronic fault on an individual fuel injector circuit; companion codes cover each remaining cylinder on the inline diesel engine. | Injector solenoid or wiring fault, corroded connector, or a failed injector. | Inspect injector wiring and the connector, then have the dealer test and, if needed, replace the affected injector. |
| D142 | Clutch/inching-pedal top-point position sensor fault reported by the power-management controller. | Misadjusted or failed inching-pedal position sensor, loose linkage, or a lost calibration. | Inspect pedal linkage and sensor mounting, run the pedal calibration procedure if available, then contact the dealer; replacing the sensor can surface a related switch fault that also needs calibration. |
| D143 | Clutch/inching-pedal bottom-point (low) position sensor fault, paired with D142. | Same root causes as D142: misadjusted or failed inching-pedal sensor or linkage. | Inspect and recalibrate the inching-pedal sensor; if the fault will not clear, contact the dealer for the calibration procedure. |
| E9006 | Defective or interrupted CAN data-bus communication across the tractor's control network. | Corroded or loose data-bus wiring/connectors, a damaged harness, or a failed module on the network. | Check main harness connectors and grounds for corrosion or looseness, then have the dealer trace the CAN network. |
| E168 | Battery/charging system voltage outside the normal range. | Loose or corroded battery terminals, a weak or failing battery, or an alternator/charging fault. | Clean and tighten battery terminals, load-test the battery, then contact the dealer if voltage stays out of range. |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
MT735 attachments & work tools
Rear three-point linkage (Category III)
Electronically controlled rear three-point linkage with integrated track-slip control, rated for roughly 7,257 kg (16,000 lb) of lift. Sized for Category III mounted tillage and other three-point implements built for this row-crop track-tractor class.
Rear quick-hitch coupler
A quick-hitch coupler for the Category III rear linkage is available across this tractor's platform (shared with its larger MT700-series siblings), letting mounted implements be picked up and dropped without manual pinning.
Rear PTO
Independent rear PTO runs at 1000 rpm through a 44 mm (1-3/4 in) spline shaft. Matches standard 1000-rpm PTO implements such as mower-conditioners, rotary cutters and balers sized for this power class.
Swinging drawbar
A swinging drawbar is standard equipment and is the primary hitch point for trailed implements such as chisel plows, disks, air seeders and grain carts, used alongside or instead of the three-point linkage.
Remote hydraulic valves / power-beyond circuit
Hydraulic circuit uses electronic spool valves, commonly 4 and expandable to 6 depending on configuration, with combined flow near 165 lpm (43.5 gpm) at about 200 bar (2,900 psi). Includes electronic power-beyond capability so trailed implements with their own remote electronic valves (planters, air carts) can draw off the tractor's circuit; implements needing power-beyond compatibility require this hydraulic arrangement rather than a basic open-center remote.
Front ballast / idler weights
Front track-frame idler weights of about 57 kg (125 lb) each can be stacked up to 24 total, or 12 per track, to counterbalance heavy rear-mounted or drawn implements. Unballasted front-to-rear weight bias runs roughly 60/40 and levels out once a loaded implement is hitched.
Track/undercarriage width options
Rubber track belts for this platform are offered in multiple widths, commonly around 460 mm, 635 mm and 760 mm (18 in, 25 in and 30 in), letting the tractor be matched to row spacing and flotation needs of different tillage and planting implements.
All MT735 assemblies by section
Every catalogued assembly group for the Caterpillar MT735. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Air Inlet And Exhaust System
174-1590 Elbow Gp-Air Inlet
| 17***90 | Elbow Group-Air Inlet | 1 |
| 1U***46 | Sealant (For Locations A) | 0 |
| 20***60 | Elbow-Air Inlet | 1 |
173-6107 Elbow Gp-Air Inlet
| 13***53 | Stud; (M8x1.25x82.75-mm)(M8x1.25x82.75-mm) | 8 |
| 17***07 | Elbow Group-Air Inlet | 1 |
| 18***71 | Elbow-Air Inlet | 1 |
171-4687 Manifold Gp-Exhaust
| 11***15 | Stud-Taperlock; (M10x85-mm Oal) | 12 |
| 16***98 | Manifold-Exhaust | 2 |
| 16***11 | Gasket | 6 |
165-4444 Manifold Gp-Exhaust
| 11***15 | Stud-Taperlock; (M10x85-mm Oal) | 12 |
| 16***98 | Manifold-Exhaust | 1 |
| 16***11 | Gasket | 6 |
169-3121 Turbocharger Gp
| 16***21 | Turbocharger Group | 1 |
| 19***46 | Turbocharger Group | 1 |
| 1P***51 | Gasket; (Turbocharger) | 1 |
206-2947 Turbocharger Gp
| 13***02 | Clamp As; (Turbine)(Turbine) | 1 |
| 16***63 | Clamp | 2 |
| 17***20 | Hose; (Wastegate) | 1 |
191-5518 Turbocharger Gp
| 19***94 | Turbocharger Group | 1 |
| 19***18 | Turbocharger Group | 1 |
| 1P***51 | Gasket; (Turbocharger) | 1 |
193-3346 Turbocharger Gp
| 13***02 | Clamp As; (Turbine)(Turbine) | 1 |
| 16***63 | Clamp | 2 |
| 17***91 | Hose; (Wastegate) | 1 |
206-4013 Turbocharger Gp
| 1P***51 | Gasket; (Turbocharger) | 1 |
| 20***47 | Turbocharger Group | 1 |
| 20***13 | Turbocharger Group | 1 |
191-5094 Turbocharger Gp
| 13***01 | Housing-Turbine | 1 |
| 13***02 | Clamp As; (Turbine)(Turbine) | 1 |
| 19***94 | Turbocharger Group | 1 |
Basic Engine
164-6100 Camshaft Gp
| 10***94 | Plate-Thrust | 1 |
| 10***09 | Gear-Camshaft; (100-Teeth) | 1 |
| 16***00 | Camshaft Group | 1 |
189-6308 Cover Gp-Cylinder Block
| 18***08 | Cover Group-Cylinder Block | 1 |
| 5F***81 | Gasket To Flywheel Housing Drain Tube Assembly | 1 |
| 5F***59 | Flange | 1 |
183-3649 Cover Gp-Cylinder Block
| 18***49 | Cover Group-Cylinder Block; -Rear | 1 |
| 20***87 | Breather As; (Crankcase) | 1 |
| 21***10 | Gasket | 1 |
216-3047 Cover Gp-Front Housing
| 06***55 | Seal-O-Ring (Id=47.22mm) | 1 |
| 06***97 | Cap-Oil Filler; (Engine Oil) | 1 |
| 12***57 | Washer; (10.85x19.3x1.27-mm Thk) | 2 |
118-1727 Cover Gp-Front Housing
| 11***27 | Cover Group-Front Housing; -Accessory Drive | 1 |
| 13***19 | Seal-Integral; (Integral) | 1 |
| 4W***26 | Cover | 1 |
166-1775 Cover Gp-Front Housing
| 06***55 | Seal-O-Ring (Id=47.22mm) | 1 |
| 12***57 | Washer; (10.85x19.3x1.27-mm Thk) | 2 |
| 13***22 | Stud | 2 |
164-6490 Cover Gp-Valve Mechanism
| 16***90 | Cover Group-Valve Mechanism | 1 |
| 20***39 | Fastener Assem. | 9 |
| 21***01 | Seal-Bulk; (23-Dm)(Valve Mechanism Cover) | 0 |
164-6148 Crankshaft Gp
| 15***39 | Bearing-Main; (Standard) | 7 |
| 16***47 | Crankshaft Assem. | 1 |
| 16***66 | Plate-Thrust | 2 |
221-3248 Cylinder Block As
| 0L***26 | Plug -13mm(.512 In.) Outside Dia. | 2 |
| 17***54 | Bolt-Hex Head; (M16x160mm) | 14 |
| 20***05 | Bearing-Sleeve; (Camshaft) | 2 |
204-9538 Cylinder Block As
| 0L***26 | Plug -13mm(.512 In.) Outside Dia. | 2 |
| 17***54 | Bolt-Hex Head; (M16x160mm) | 14 |
| 20***05 | Bearing-Sleeve; (Camshaft) | 2 |
161-3406 Cylinder Block Gp
| 0S***19 | Plug-Cup | 1 |
| 16***06 | Cylinder Block Group | 1 |
| 1W***07 | Sleeve | 2 |
220-1952 Cylinder Block Gp
| 03***53 | Seal-O-Ring; (08.92mm Id) | 1 |
| 16***24 | Seal-Liner | 6 |
| 19***62 | Liner-Cylinder Block | 6 |
204-9539 Cylinder Block Gp
| 03***53 | Seal-O-Ring; (08.92mm Id) | 1 |
| 16***24 | Seal-Liner | 6 |
| 19***62 | Liner-Cylinder Block | 6 |
201-2180 Cylinder Head As
| 17***88 | Seat-Valve | 12 |
| 17***90 | Seat-Valve | 12 |
| 17***37 | Sleeve-Injector | 6 |
210-5985 Cylinder Head As
| 17***88 | Seat-Valve | 12 |
| 17***90 | Seat-Valve | 12 |
| 21***85 | Cylinder Head As | 1 |
210-5987 Cylinder Head Gp
| 16***71 | Fastener Group-Cylinder Head | 26 |
| 18***15 | Gasket Assem. | 1 |
| 21***84 | Cylinder Head Group | 1 |
161-3405 Cylinder Head Gp
| 16***05 | Cylinder Head Group | 1 |
| 16***71 | Fastener Group-Cylinder Head | 26 |
| 18***15 | Gasket Assem. | 1 |
210-5984 Cylinder Head Gp
| 15***06 | Seal-O-Ring; (11.89mm Id) | 5 |
| 16***42 | Valve; (Intake) | 12 |
| 16***44 | Guide-Valve | 24 |
201-2181 Cylinder Head Gp
| 03***53 | Seal-O-Ring; (08.92mm Id) | 6 |
| 15***06 | Seal-O-Ring; (11.89mm Id) | 5 |
| 16***42 | Valve; (Intake) | 12 |
169-3539 Damper & Pulley Gp
| 15***36 | Pulley-Crankshaft; (8-Groove) | 1 |
| 16***39 | Damper & Pulley Group | 1 |
| 20***19 | Damper As | 1 |
192-3833 Damper & Pulley Gp
| 15***36 | Pulley-Crankshaft; (8-Groove) | 1 |
| 16***21 | Damper Assem. | 1 |
| 19***33 | Damper & Pulley Group | 1 |
202-0103 Drain Gp-Engine Oil
| 20***03 | Drain Group-Engine Oil | 1 |
| 3K***60 | Seal Pilot Manifold On; Seal To Boom Check Valve Drain | 1 |
| 6V***38 | Valve-Shutoff; (Engine Oil Pan Drain) | 1 |
202-2025 Drive Gp-Fan
| 10***26 | Retainer-Bearing | 1 |
| 11***38 | Plate; (Thrust) | 1 |
| 12***56 | Shaft-Fan | 1 |
167-0171 Fastener Gp-Cylinder Head
| 16***71 | Fastener Group-Cylinder Head | 1 |
| 18***63 | Bolt; (M16x2x180-mm) | 1 |
| 9X***68 | Washer; (17.5x30x3.5-mm Thk) | 1 |
169-3106 Fastener Gp-Engine
| 16***06 | Fastener Group-Engine | 1 |
| 4K***90 | Washer; (8.6x17.3x1.6-mm Thk) | 6 |
| 6V***19 | Bolt; (M8x1.25x40-mm) | 6 |
117-2794 Fastener Gp-Flywheel
| 11***94 | Fastener Group-Flywheel; (Flywheel) | 1 |
| 5P***47 | Washer (Bracket To Valve Support) | 8 |
| 9X***21 | Bolt; (Locking) (M16x2.0x45mm) | 8 |
166-1788 Fastener Gp-Front Housing
| 16***88 | Fastener Group-Front Housing | 1 |
| 6V***17 | Bolt; (M8x1.25x30-mm)(Location Z) | 5 |
| 8T***00 | Bolt (M8x1.25x60mm); (M8x1.25x60-mm) | 1 |
116-4556 Fastener Gp-Front Housing
| 11***56 | Fastener Group-Front Housing; (Housing) | 1 |
| 5P***45 | Washer-Hard; (13.5x25.5x3-mm Thk)(Turbocharger Blanking Plate) | 6 |
| 6V***36 | Bolt; (M12x1.75x70-mm) | 6 |
173-7123 Fastener Gp-Front Housing
| 17***23 | Fastener Group-Front Housing | 1 |
| 6V***17 | Bolt; (M8x1.25x30-mm)(Location Z) | 4 |
| 8T***00 | Bolt (M8x1.25x60mm); (M8x1.25x60-mm) | 1 |
201-5534 Flywheel Gp
| 15***05 | Pulley-Rear | 1 |
| 16***87 | Gear-Flywheel; (134-Teeth)(Id 405.14mm) | 1 |
| 17***86 | Bolt; (M16x2x115-mm) | 8 |
171-4684 Flywheel Gp
| 15***05 | Pulley-Rear | 1 |
| 16***56 | Flywheel As | 1 |
| 16***87 | Gear-Flywheel; (134-Teeth)(Id 405.14mm) | 1 |
145-9112 Flywheel Gp
| 14***53 | Flywheel As | 1 |
| 14***12 | Flywheel Group | 1 |
| 4N***14 | Gear; (113-Teeth)(Flywheel Starter) | 1 |
155-7918 Gear Gp-Front
| 11***69 | Plate-Thrust | 1 |
| 11***72 | Bearing | 1 |
| 11***19 | Plate-Retaining | 1 |
155-7935 Housing Gp-Flywheel
| 06***55 | Seal-O-Ring (Id=47.22mm) | 1 |
| 15***35 | Housing Group-Flywheel | 1 |
| 1P***69 | Plug-Seal; (Flywheel Housing Drain) | 3 |
165-4446 Housing Gp-Front
| 16***46 | Housing Group-Front | 1 |
| 1U***46 | Sealant (For Locations A) | 0 |
| 23***16 | Housing-Front | 1 |
193-3293 Lifting Gp-Engine
| 19***93 | Lifting Group-Engine | 1 |
| 19***94 | Plate-Lift Eye | 1 |
| 5P***45 | Washer-Hard; (13.5x25.5x3-mm Thk)(Turbocharger Blanking Plate) | 3 |
169-3113 Lifting Gp-Engine
| 16***85 | Plate-Lifting; (Rear) | 1 |
| 16***13 | Lifting Group-Engine | 1 |
| 5P***45 | Washer-Hard; (13.5x25.5x3-mm Thk)(Turbocharger Blanking Plate) | 3 |
187-3884 Mounting Gp-Fan Drive
| 18***84 | Mounting Group-Fan Drive | 1 |
| 18***87 | Support As-Fan | 1 |
| 18***56 | Block | 1 |
187-3076 Pan Gp-Oil
| 18***85 | Pan-Oil; (Engine Oil) | 1 |
| 18***76 | Pan Group-Oil; -Engine | 1 |
| 19***14 | Gasket-Oil Pan; (Engine) | 1 |
188-9141 Piston & Rod Gp
| 15***51 | Skirt-Piston | 1 |
| 16***72 | Bearing-Connecting Rod | 1 |
| 16***97 | Bolt | 2 |
177-7878 Piston Gp
| 17***78 | Piston Group | 1 |
| 18***41 | Piston & Rod Group | 6 |
169-3105 Plug Gp-Engine
| 16***05 | Plug Group-Engine | 1 |
| 3D***24 | O-Ring - For Oil Drain & Level Plug (Items 3 & 7) | 1 |
| 6V***49 | Seal-O-Ring (Id=11.89mm); (11.89-mm Id) | 2 |
206-6437 Plug Gp-Engine
| 20***37 | Plug Group-Engine | 1 |
| 3D***24 | O-Ring - For Oil Drain & Level Plug (Items 3 & 7) | 2 |
| 5P***17 | Adapter- To Logic Valve 1u***59 | 1 |
7e-2313 Drain Gp-Engine Oil
| 3K***60 | Seal Pilot Manifold On; Seal To Boom Check Valve Drain | 1 |
| 7E***13 | Plug Group-Oil Pan | 1 |
| 9X***30 | Plug-Drain; (Magnetic)(Engine Oil Pan) | 1 |
193-1726 Pulley Gp
| 10***26 | Retainer-Bearing | 1 |
| 11***38 | Plate; (Thrust) | 1 |
| 12***56 | Shaft-Fan | 1 |
175-3223 Pulley As-Idler
| 12***90 | Bolt; (M10x1.5) | 1 |
| 12***91 | Cover-Dust | 1 |
| 12***92 | Pulley As-Idler; (8-Groove) | 1 |
213-9320 Rocker Arm Gp -Exhaust
| 16***47 | Rocker Arm As | 1 |
| 18***65 | Screw-Adjustment; (M10x1.5-Thd) | 1 |
| 21***20 | Rocker Arm Group; -Exhaust | 1 |
213-9321 Rocker Arm Gp -Intake
| 16***49 | Rocker Arm As | 1 |
| 18***65 | Screw-Adjustment; (M10x1.5-Thd) | 1 |
| 21***21 | Rocker Arm Group; -Intake | 1 |
178-3899 Seal Gp-Crankshaft
| 11***21 | Seal Group-Crankshaft; (Front) | 1 |
| 17***99 | Seal Group-Crankshaft | 1 |
| 18***61 | Seal Group-Crankshaft; (Rear) | 1 |
171-4685 Support Gp-Engine
| 16***06 | Support-Rear | 1 |
| 17***85 | Support Group-Engine | 1 |
| 1U***46 | Sealant (For Locations A) | 0 |
185-5334 Support Gp-Engine
| 18***34 | Support Group-Engine; -Front | 1 |
| 20***44 | Support-Engine | 2 |
| 6V***44 | Bolt; (M16x2.0x35mm) | 4 |
215-9571 Valve Mechanism Gp
| 16***45 | Shaft As-Rocker Arm | 1 |
| 16***59 | Spring | 6 |
| 16***69 | Stand; (End) | 2 |
155-7927 Valve Mechanism Gp
| 13***79 | Rod-Valve Push; (Valve Push) | 12 |
| 15***27 | Valve Mechanism Group | 1 |
| 16***37 | Lifter As-Valve | 12 |
163-2450 Valve Mechanism Gp
| 16***94 | Insert-Rocker Arm | 2 |
| 16***45 | Shaft As-Rocker Arm | 1 |
| 16***46 | Rocker Arm Group; (Exhaust) | 6 |
Cooling System
188-3826 Cooler Gp-Engine Oil
| 18***26 | Cooler Group-Engine Oil | 1 |
| 20***93 | Gasket | 1 |
| 23***56 | Core As-Oil Cooler; (Engine) | 1 |
187-3066 Cover Gp-Water Outlet
| 18***07 | Seal-Integral | 1 |
| 18***36 | Cover | 1 |
| 18***66 | Cover Group-Water Outlet | 1 |
165-4461 Lines Gp-Water
| 14***11 | Plug Group | 2 |
| 16***61 | Lines Group-Water; -Water Temperature Regulator | 1 |
| 16***24 | Hose | 1 |
208-0440 Lines Gp-Water
| 16***24 | Hose | 1 |
| 19***57 | Gasket; (Water Regulator Housing)(Temperature) | 1 |
| 20***40 | Lines Group-Water; -Water Temperature Regulator | 1 |
205-4013 Plug Gp-Water Lines
| 20***13 | Plug Group-Water Lines; -Coolant | 1 |
| 20***34 | Plug-Cup; (73.38-mm Dia) | 2 |
| 7L***56 | Plug-Cup; (67.03-mm Dia) | 2 |
208-0333 Pump Gp-Water
| 20***32 | Pump Group-Water | 1 |
| 20***33 | Pump Group-Water | 1 |
| 2M***53 | Seal--To Seal Brake Housing To Main Housing | 1 |
208-0332 Pump Gp-Water
| 14***88 | Seal As; (Water Pump) | 1 |
| 17***44 | Cover | 1 |
| 17***52 | Shaft As | 1 |
165-4478 Pump Gp-Water
| 16***78 | Pump Group-Water | 1 |
| 18***82 | Pump Group-Water | 1 |
| 2M***53 | Seal--To Seal Brake Housing To Main Housing | 1 |
187-8982 Pump Gp-Water
| 06***69 | Stem | 1 |
| 14***88 | Seal As; (Water Pump) | 1 |
| 17***44 | Cover | 1 |
Electrical And Starting System
188-3506 Alternator Gp-Charging
| 11***79 | Alternator Group-Charging | 1 |
| 12***40 | Support-Alternator | 1 |
| 13***82 | Support-Alternator | 1 |
117-1379 Alternator Gp-Charging
| 03***12 | Screw-Forming; (10-24x0.5-In) | 3 |
| 10***86 | Stator As-Alternator | 1 |
| 11***79 | Alternator Group-Charging | 1 |
208-2385 Connection Gp-Electrical
| 10***29 | Stud; (M10x1.5-Thd) | 1 |
| 10***03 | Cap; (Stud Protector) | 1 |
| 20***85 | Connection Group-Electrical | 1 |
206-6446 Connection Gp-Electrical
| 20***46 | Connection Group-Electrical; -Air Inlet Heater | 1 |
| 20***96 | Cable As | 1 |
| 3T***88 | Terminal-Ring; (4-Ga, 7/16-In Screw) | 1 |
180-6004 Connection Gp-Electrical
| 10***29 | Stud; (M10x1.5-Thd) | 1 |
| 10***03 | Cap; (Stud Protector) | 1 |
| 18***04 | Connection Group-Electrical | 1 |
165-4468 Control & Mtg Gp-Engine Elek
| 10***28 | Spacer-Special; (12.7x26x28.7-mm Thk) | 2 |
| 16***68 | Control & Mtg Group-Engine Elek | 1 |
| 16***11 | Spacer | 2 |
196-4173 Control Gp-Engine Electronic
| 19***72 | Control Group-Engine Electronic | 1 |
| 19***73 | Control Group-Engine Electronic | 1 |
196-4172 Control Gp-Engine Electronic
| 18***72 | Screw-Pan Head; (No 8-32x9.52-mm)(Wax Coated) | 1 |
| 19***72 | Control Group-Engine Electronic | 1 |
| 7X***15 | Strap; (Grounding) | 1 |
201-0194 Heater Gp-Air Inlet
| 19***59 | Heater As-Air Inlet | 1 |
| 1U***46 | Sealant (For Locations A) | 0 |
| 20***94 | Heater Group-Air Inlet | 1 |
205-6289 Heater Gp-Jacket Water
| 18***36 | Cord As; -Jacket Water Heater | 1 |
| 20***89 | Heater Group-Jacket Water | 1 |
| 20***34 | Plug-Cup; (73.38-mm Dia) | 2 |
4p-1479 Heater Gp-Starting Aid
| 15***11 | Heater As; (Starting Aid) | 1 |
| 1U***46 | Sealant (For Locations A) | 0 |
| 4P***79 | Heater Group-Starting Aid; -Air Inlet Heater | 1 |
177-9816 Mounting Gp-Solenoid
| 17***16 | Mounting Group-Solenoid; -Starting Aid | 1 |
| 19***85 | Bracket | 1 |
| 3E***53 | Washer-Hard; (11x25x3-mm Thk) | 2 |
165-4469 Sensor Gp-Engine
| 11***85 | Seal-O-Ring; (13.94mm Id) | 2 |
| 13***11 | Sensor Group-Temperature; (Transmission Lubrication Oil) | 2 |
| 13***67 | Seal-O-Ring | 1 |
169-3300 Sensor Gp-Speed -Timing
| 16***00 | Sensor Group-Speed; -Engine Timing | 1 |
130-9811 Sensor Gp-Temperature
| 13***11 | Sensor Group-Temperature; (Transmission Lubrication Oil) | 1 |
191-6587 Sensor Gp-Temperature -Engine Oil
| 15***43 | Sleeve; (2.8-Dm) | 0 |
| 15***61 | Wedge-Plug Lock; (2-Pin) | 1 |
| 15***70 | Kit-Connecting Plug; (2-Pin)(Engine Sensor Wiring Harness) | 1 |
101-8936 Starting Motor Gp-Electric
| 10***36 | Starting Motor Group-Electric | 1 |
| 15***25 | Gasket | 1 |
| 20***24 | Starting Motor Group-Electric | 1 |
207-1524 Starting Motor Gp-Electric
| 03***23 | Bolt; (1/4-28x1-In) | 5 |
| 20***89 | Kit-Solenoid; (12-Volt)(Starting Motor) | 1 |
| 20***24 | Starting Motor Group-Electric | 1 |
175-2303 Switch Gp-Magnetic -Air Inlet Heater
| 01***80 | Lockwasher | 2 |
| 10***02 | Kit-Receptacle; (2-Pin)(Engine Sensor Wiring Harness) | 1 |
| 17***03 | Switch Group-Magnetic; -Air Inlet Heater | 1 |
209-1953 Wiring Gp-Electronic Control
| 00***35 | Protector | 1 |
| 10***20 | Plug As-Connector; (2-Pin) | 1 |
| 10***02 | Kit-Receptacle; (2-Pin)(Engine Sensor Wiring Harness) | 2 |
188-9869 Wiring Gp-Electronic Control
| 00***35 | Protector | 1 |
| 01***80 | Lockwasher | 2 |
| 10***20 | Plug As-Connector; (2-Pin) | 1 |
Engine Arrangement
177-1414 Engine Ar
| 11***56 | Fastener Group-Front Housing; (Housing) | 1 |
| 11***27 | Cover Group-Front Housing; -Accessory Drive | 1 |
| 16***90 | Cover Group-Valve Mechanism | 1 |
194-4160 Engine Ar
| 11***56 | Fastener Group-Front Housing; (Housing) | 1 |
| 11***27 | Cover Group-Front Housing; -Accessory Drive | 1 |
| 16***90 | Cover Group-Valve Mechanism | 1 |
179-4958 Engine Ar
| 11***56 | Fastener Group-Front Housing; (Housing) | 1 |
| 11***27 | Cover Group-Front Housing; -Accessory Drive | 1 |
| 16***90 | Cover Group-Valve Mechanism | 1 |
179-4956 Engine Ar
| 11***56 | Fastener Group-Front Housing; (Housing) | 1 |
| 11***27 | Cover Group-Front Housing; -Accessory Drive | 1 |
| 16***90 | Cover Group-Valve Mechanism | 1 |
179-4954 Engine Ar
| 11***56 | Fastener Group-Front Housing; (Housing) | 1 |
| 11***27 | Cover Group-Front Housing; -Accessory Drive | 1 |
| 16***90 | Cover Group-Valve Mechanism | 1 |
177-1420 Engine Ar
| 10***36 | Starting Motor Group-Electric | 1 |
| 11***56 | Fastener Group-Front Housing; (Housing) | 1 |
| 11***94 | Fastener Group-Flywheel; (Flywheel) | 1 |
177-1418 Engine Ar
| 11***56 | Fastener Group-Front Housing; (Housing) | 1 |
| 11***27 | Cover Group-Front Housing; -Accessory Drive | 1 |
| 16***90 | Cover Group-Valve Mechanism | 1 |
177-1416 Engine Ar
| 11***56 | Fastener Group-Front Housing; (Housing) | 1 |
| 11***27 | Cover Group-Front Housing; -Accessory Drive | 1 |
| 16***90 | Cover Group-Valve Mechanism | 1 |
179-4952 Engine Ar
| 11***56 | Fastener Group-Front Housing; (Housing) | 1 |
| 11***27 | Cover Group-Front Housing; -Accessory Drive | 1 |
| 16***90 | Cover Group-Valve Mechanism | 1 |
177-1417 Engine Ar-Core
| 15***18 | Gear Group-Front | 1 |
| 15***27 | Valve Mechanism Group | 1 |
| 16***06 | Cylinder Block Group | 1 |
177-1415 Engine Ar-Core
| 15***18 | Gear Group-Front | 1 |
| 15***27 | Valve Mechanism Group | 1 |
| 16***06 | Cylinder Block Group | 1 |
194-4161 Engine Ar-Core
| 15***18 | Gear Group-Front | 1 |
| 15***27 | Valve Mechanism Group | 1 |
| 16***06 | Cylinder Block Group | 1 |
177-1421 Engine Ar-Core
| 15***18 | Gear Group-Front | 1 |
| 15***27 | Valve Mechanism Group | 1 |
| 16***05 | Cylinder Head Group | 1 |
177-1419 Engine Ar-Core
| 15***18 | Gear Group-Front | 1 |
| 15***27 | Valve Mechanism Group | 1 |
| 16***06 | Cylinder Block Group | 1 |
Frame And Body
206-5947 Mounting Gp -Solenoid
| 20***46 | Bracket | 1 |
| 20***47 | Mounting Group; -Solenoid | 1 |
| 3E***53 | Washer-Hard; (11x25x3-mm Thk) | 2 |
Fuel System
236-0962 Injector Gp-Fuel
| 10***07 | Seal-O-Ring; (Fuel System) | 1 |
| 14***03 | Seal-O-Ring; (Fuel System) | 1 |
| 14***40 | Ring-Backup; (37.36mm Od), Flasher Switch; Hazard, Replaces 421164a1, Flasher Switch | 1 |
217-2570 Injector Gp-Fuel
| 10***07 | Seal-O-Ring; (Fuel System) | 1 |
| 14***03 | Seal-O-Ring; (Fuel System) | 1 |
| 14***40 | Ring-Backup; (37.36mm Od), Flasher Switch; Hazard, Replaces 421164a1, Flasher Switch | 1 |
204-7454 Lines Gp-Fuel
| 03***42 | Elbow Hose Assembly To | 1 |
| 03***47 | Elbow-Filtered Fuel From Based Assembly | 3 |
| 03***55 | Tee-Flared | 1 |
189-3803 Lines Gp-Fuel Filter
| 00***15 | Insert | 1 |
| 03***42 | Elbow Hose Assembly To | 1 |
| 03***47 | Elbow-Filtered Fuel From Based Assembly | 1 |
172-5780 Pump Gp-Unit Injection
| 17***80 | Pump Group-Unit Injection | 1 |
| 23***51 | Bolt-Socket Head; (M8x1.25x65-mm) | 2 |
| 23***62 | Injector Group-Fuel | 1 |
166-1759 Pump Gp-Unit Injection
| 16***59 | Pump Group-Unit Injection | 1 |
| 17***80 | Pump Group-Unit Injection | 6 |
165-4450 Pump Gp-Unit Injector Hyd
| 03***50 | Elbow (Check Valve Drain Tube) | 1 |
| 15***06 | Seal-O-Ring; (11.89mm Id) | 3 |
| 15***07 | Seal-O-Ring | 2 |
204-4944 Pump Gp-Unit Injector Hyd
| 20***44 | Pump Group-Unit Injector Hydraulic | 1 |
Lubrication System
183-3700 Filter Gp-Engine Oil
| 03***53 | Seal-O-Ring; (08.92mm Id) | 1 |
| 18***56 | Base As-Oil Filter | 1 |
| 18***00 | Filter Group-Engine Oil | 1 |
206-6441 Filter Gp-Engine Oil
| 1R***16 | Filter As-Engine Oil; (Standard Efficiency) | 1 |
| 20***62 | Seal | 1 |
| 20***41 | Filter Group-Engine Oil | 1 |
187-3077 Fumes Disposal Gp
| 18***77 | Fumes Disposal Group | 1 |
| 19***31 | Bracket | 1 |
| 19***10 | Hose-Fumes Disposal | 1 |
201-5535 Fumes Disposal Gp
| 12***71 | Clamp-Hose | 1 |
| 1D***64 | Spacer; (15.8x21.34x25-mm Thk) | 1 |
| 20***35 | Fumes Disposal Group | 1 |
187-0710 Gauge Gp-Oil Level (Dipstick)
| 18***10 | Gauge Group-Oil Level (Dipstick); -Engine | 1 |
| 18***16 | Tube As-Guide; (Rh) | 1 |
| 19***33 | Gauge-Oil Level; (Dipstick, Engine) | 1 |
176-5328 Gauge Gp-Oil Level (Dipstick)
| 17***28 | Gauge Group-Oil Level (Dipstick); -Engine | 1 |
| 18***14 | Gauge-Oil Level; (Dipstick, Engine) | 1 |
| 18***16 | Tube As-Guide; (Rh) | 1 |
192-2833 Lines Gp-Engine Oil
| 03***34 | Seal-O-Ring | 1 |
| 19***33 | Lines Group-Engine Oil | 1 |
| 19***52 | Gasket | 1 |
188-3028 Lines Gp-Engine Oil
| 16***80 | Tube As | 1 |
| 18***28 | Lines Group-Engine Oil | 1 |
| 19***74 | Elbow-Outlet | 1 |
165-4465 Lines Gp-Turbocharger Oil
| 16***65 | Lines Group-Turbocharger Oil | 1 |
| 16***66 | Tube As | 1 |
| 18***98 | Connector As | 1 |
188-8840 Lines Gp-Turbocharger Oil
| 18***99 | Connector As | 1 |
| 18***40 | Lines Group-Turbocharger Oil | 1 |
| 18***41 | Hose As | 1 |
195-8098 Pump Gp-Engine Oil
| 19***98 | Pump Group-Engine Oil; (Engine Oil) | 1 |
| 21***22 | Pump As-Engine Oil | 1 |
| 21***46 | Gerotor Pump Group | 1 |
Operator Station
188-3507 Compressor Gp-Refrigerant
| 12***37 | Support-Compressor | 1 |
| 18***07 | Compressor Group-Refrigerant | 1 |
| 2Y***29 | Nut-Hard; (M10 X 1.5) | 2 |
MT735 serial number reference
The PIN plate sits on the main tractor frame at the front left side, near the front idler/equalizer area. Read it as a 3-character prefix (letters) followed by a numeric sequence number; the prefix identifies the model/build series and the sequence number pins down the individual unit and approximate build date within that run.
| Prefix | Identifies | Notes |
|---|---|---|
| AKN | MT735 rubber-track Challenger, full production run (2002-2004 model years, all configurations) | Only PIN prefix documented for this model, covering the machine from its 2002 introduction through the 2004 model year, with parts support continuing after. Fitted with the Caterpillar 8.8 L (C9) diesel, rated at 235 hp (175 kW) gross with a claimed 185 hp (138 kW) PTO rating. Assembled at the Jackson, Minnesota plant, with Caterpillar supplying the engine and driveline. No B-suffix successor was built in this power class; the later MT700B line starts at the next size up. |
Frequently asked questions
What engine does the Caterpillar MT735 use?
The MT735 runs a Caterpillar C9, an 8.8 L inline-six turbodiesel, rated at 235 hp gross with 185 PTO hp and 178 hp drawbar. It pairs with a 16-speed powershift transmission, with a 30-speed creeper transmission available as an option.
What is the operating weight of the MT735?
Operating weight runs around 12,784 kg (28,185 lb), varying with ballast, track width, and attached implements or work tools.
What replaced the Caterpillar MT735?
No direct successor exists in the MT735's own numbering. Its larger A-series stablemates (MT745, MT755, MT765) continued on into "B" updates, but Caterpillar never released an MT735B; the smallest A-series model was discontinued rather than replaced one-for-one. The Challenger/AGCO lineup carried the MT700 nameplate forward into later B/C/D-series tractors with AGCO Power engines at substantially higher horsepower, occupying the same market segment without being a direct MT735 replacement.
What MT735 owners discuss
What's the real-world reliability of the Cat C9 engine in the MT735?
Long-run owners describe the C9 as a strong-pulling, low-drama engine that keeps working past 5,000 to 8,000-plus hours with routine oil and filter service. Most report replacing only belts, an idler, and tracks over that span, not engine internals. The one recurring engine flag on this HEUI-injected C9 is fuel working into the crankcase oil over time, usually traced to injector O-rings/seals or the fuel transfer pump shaft seal rather than outright injector failure. Watch for a rising oil level or a diesel smell on the dipstick and pull the injectors before it washes down cylinder walls. Have your dealer verify the source of any oil dilution before returning the engine to full load.
How does the 16-speed powershift transmission hold up, and what do owners do wrong with it?
The Cat 16-speed full powershift (30-speed with the creeper option) is built heavier than the loads it usually sees and regularly runs past 20,000 hours before needing an overhaul. The most common owner-caused problem is using the inching pedal like a clutch pedal in the field. It's meant only for slow, controlled hookups, and riding it under load glazes and overheats the clutch packs. Change transmission oil on schedule, roughly every 1,000 hours, and have the control system recalibrated with dealer software every time oil is changed. Skipping recalibration is a common reason shifting turns harsh or mistimed afterward. Have your dealer verify clutch pack condition if the transmission has a history of inching-pedal use under load.
What hydraulic quirks are specific to these early A-series machines?
Factory hydraulic flow on the MT735 is rated around 165 L/min (43.5 gpm) at roughly 200 bar (2,900 psi). Flow capacity climbed a lot across the platform's life. Operators moving from this early A-series machine to a later Challenger track tractor consistently note the newer machines handle high-demand implements, like air carts and wide planters, with less oil-temperature rise than the earlier pump and reservoir setup. If you're running big-flow implements on an A-series machine, plan on extra cooler capacity or confirm the pump has already been upgraded from stock.
What track and undercarriage wear patterns should I expect to manage?
A set of rubber tracks typically lasts roughly 2,000 to 4,000 hours, varying a lot with soil abrasiveness and how much road transport the machine sees. Check guide lugs and the underside of the belt at each inspection. Wear concentrated on one side of the guide lugs points to an alignment problem, and wear on the belt underside or lug faces usually traces back to worn mid-rollers. Mid-rollers wearing into a slight dome shape is normal. Flat spots, edge cuts, or bare patches down to the steel carcass mean replace before the belt itself gets damaged. Keep onboard tanks empty for road travel when you can, or slow down with full tanks. Running loaded at transport speed builds heat in the tracks fast.
Are there any known final-drive or driveline weak points on the MT735?
Early production of this platform carried final drives with narrower bearing spacing than what came later, and that spacing has been linked to bearing failures under sustained heavy mounted-implement loads. Wider final drives addressed this on later-built machines. On an early unit, feel and listen for play or noise from both final drives during a test run under load, and check the rear driveline reaction-arm oil level and seals. That housing runs a small reservoir, and a leak there can go unnoticed until the bearings inside are damaged. Have your dealer verify final drive bearing condition before putting the tractor back into heavy pulling duty.
What electrical or sensor issues come up most on these tractors?
The transmission's electronic controls need recalibrating with dealer diagnostic software any time the transmission oil is changed or a related sensor is disturbed. Skip that step and you can get erratic shift quality or a stored fault code that isn't actually a mechanical problem. Beyond that, most electrical complaints on a machine this age come down to corroded or loose connector pins and chafed harness sections causing intermittent gauge or sensor readings, not one single known failure unique to this model. Clean and reseat connectors and check grounds before replacing a sensor or module.
What should I check before buying a used MT735?
Ask for maintenance records first. Engines and transmissions in this family routinely reach 10,000-plus hours under sensible ownership, and a machine that's passed through only one or two owners tends to show less abuse than the hour meter alone suggests. On the walk-around, check guide-lug wear and mid-roller shape on both tracks, look for oil weeping around the final drives and the rear driveline reaction-arm seals, and run the transmission through its full range checking for clean shifts without hunting or clunking. Check hydraulic oil for a milky or burnt smell, and start the engine cold if you can. White or blue exhaust smoke on startup that doesn't clear points to injector or ring wear you'll need to budget for. These machines are now 20-plus years old, so have your dealer verify final drive bearing condition, transmission calibration status, and engine blow-by and compression before you commit to a purchase.
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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