Caterpillarengine - trucktruck engine
Caterpillar 1693
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar 1693 is a heavy-duty, six-cylinder, dual-overhead-cam diesel built for Class 8 on-highway trucks and was Caterpillar's first purpose-built entry into the highway tractor engine market. Displacement is 14.6 L (893 cu in) from a 137 mm (5.4 in) bore and 165 mm (6.5 in) stroke, with four valves per cylinder, an individual injection pump per cylinder, a precombustion-chamber (indirect injection) design, and a single turbocharger. Caterpillar offered it as the turbocharged-only 1693T and the turbocharged-aftercooled 1693TA, with factory ratings spanning roughly 270 to 425 hp depending on rating and year; reported dry engine weight ranges from about 1,460 to 2,175 kg (3,225-4,800 lb) depending on configuration and accessories, so treat any single figure as approximate and verify against the specific unit. Cat built the 1693 from the mid-1960s through 1976, when the 3406 took over as the on-highway flagship; it shares its bottom end - crankshaft, connecting rods, and general architecture - with the 3406 that replaced it, and its head and cam-drive layout trace back to Cat's D343 industrial and dozer engine. Trucks carrying it included Freightliner, Peterbilt, and Kenworth conventional and cabover tractors.
Ratings climbed across the run as Cat added boost and aftercooling: early non-aftercooled 1693T versions sat in the 270-325 hp range, while later 1693TA ratings pushed 375-425 hp and became a favorite with owner-operators on long-haul western routes, with some running well past a million miles on the original bottom end before major work. The dual-overhead-cam valve train that gave the engine strong low-end torque also meant Caterpillar never offered a factory engine brake for it, a gap that pushed fleets toward the 3406 once it arrived. Today the 1693 is a legacy engine: factory support ended decades ago, so precombustion chambers, injection pump components, and other detail parts are scarce and often sourced from salvage cores or specialist rebuilders. It stays relevant mainly to classic Class 8 truck restorers, owner-operators keeping older iron on the road, and the used-engine and parts market that supplies both.
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 1693 specifications
Engine
| Model / variants | Cat 1693 truck diesel engine family; offered as 1693 (naturally aspirated base), 1693T (turbocharged, non-aftercooled) and 1693TA (turbocharged, aftercooled). Twin overhead-camshaft design with a precombustion-chamber (PC) fuel system. |
| Configuration | Inline 6-cylinder, 4-stroke-cycle diesel, dual overhead cam, 4 valves per cylinder, rear gear train, precombustion-chamber injection |
| Displacement | 14.6-14.7 L (893 cu in) |
| Bore x stroke | 137 mm x 165 mm (5.4 in x 6.5 in) |
| Compression ratio | Approximately 14.5:1 - not documented on an OEM spec sheet for this serial range; treat as approximate. |
| Power - 1693T | 325 hp (242 kW) @ 2100 rpm, 1000-1050 lb-ft (1356-1424 Nm) peak torque @ ~1485 rpm |
| Power - 1693TA (mid rating) | 375-380 hp (280-283 kW) @ 2100 rpm, 1145-1275 lb-ft (1552-1729 Nm) peak torque @ 1400-1475 rpm |
| Power - 1693TA (top rating) | 425 hp (317 kW) @ 2100 rpm, 1275-1400 lb-ft (1729-1898 Nm) peak torque @ 1400 rpm |
| Governed speed | Approximately 2100 rpm |
| Turbocharger | Turbocharged; aftercooled on TA variants, non-aftercooled on T variants |
| Emissions tier | Not applicable - engine predates EPA/on-highway diesel emissions certification programs |
| Production era | Introduced 1964; factory production window runs through roughly 1976-1977 as the 3406 took over, with a field-service tail reported into 1980-1981 for special orders and existing chassis builds. |
Weights
| Engine weight (dry, approx.) | Approximately 1460-2175 kg (3225-4800 lb); figures vary by configuration (1693T vs 1693TA) and accessory fitment such as the Brakesaver retarder - varies by configuration/series, treat any single figure as approximate. |
Dimensions
| Overall engine dimensions | Not reliably documented for this engine - figures found could not be corroborated and are omitted rather than risk mixing in data from an unrelated engine listing. |
Performance
| Note | The 1693 is a truck engine, not a complete machine or chassis; there are no manufacturer-published travel speed, drawbar, dig, lift, or gradeability figures tied to the engine itself. Peak torque and rated power are listed under Engine. |
Service capacities (summary)
| Engine oil (lube system) | Approximately 80-85 L (21-23 US gal); not confirmed against an OEM operation and maintenance manual for this serial range - verify with your dealer. A Brakesaver-equipped engine runs about 11 L (3 US gal) more, since the retarder draws its working fluid from the engine sump. |
| Cooling system | Not documented for the 1693 itself. A cooling-capacity figure surfaced during research but belongs to an unrelated, much larger Caterpillar engine family and was excluded to avoid misattributing capacity data. Radiator sizing was set by the truck chassis builder, not by the engine OMM, so capacity varies by chassis. |
| Fuel system | Direct/precombustion-chamber diesel fuel system; no engine-mounted fuel tank capacity applies (fuel tank is chassis-mounted on the host truck, not engine-specific) |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
1693 fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with filter) | Not consistently documented for the base 1693. A Brakesaver-equipped 1693 carries about 11 L (3 US gal) more oil than a standard engine, since the retarder draws from the engine sump. Absolute fill figure varies - confirm against the service manual for serial prefix 65B. | No by-name Cat oil recommendation for this engine could be confirmed. The 1693 predates Cat's modern DEO/TDTO/ELC product naming, so period literature references an earlier Cat diesel engine oil standard - verify exact wording against the service manual for this serial range. |
| Cooling system | Not documented for the 1693 engine itself. Radiator sizing and system capacity were set by the truck chassis builder (Peterbilt, Kenworth, Autocar, White, and others integrated this engine), not by the engine OMM, so capacity varies by chassis/configuration. | Not documented for this engine specifically; follow the chassis manufacturer's coolant/antifreeze specification for the truck the engine is installed in. |
| Fuel tank | Not applicable to the engine OMM - the fuel tank is chassis-supplied by the truck manufacturer, outside the scope of the 1693 engine documentation. | Not applicable; follow chassis manufacturer's fuel spec. |
| Brakesaver hydraulic retarder (factory-installed option) | No separate hydraulic tank. The Brakesaver draws its working fluid from the engine oil sump, which is why a Brakesaver-equipped engine's crankcase runs roughly 11 L (3 US gal) larger than the standard 1693 crankcase. | Uses the engine's own crankcase oil as the retarder working fluid - no separate fluid to specify. |
| Transmission / final drives / axles | Not applicable - the 1693 is sold as a truck engine only. Transmission, final drives, and axles are documented by the truck/driveline manufacturer, not in the engine OMM. | Not applicable; consult the transmission/axle manufacturer's literature. |
| Grease (chassis/general spec) | Spec only - no grease capacity applies to an engine-only product. | Not documented specifically for the 1693; general period Cat multipurpose chassis grease practice would apply but could not be confirmed as tied to this engine. |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar 1693 maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 50 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 6,000 h |
|
Servicing the 1693 beyond the schedule
Predictive maintenance & fluid analysis
Run regular oil sampling on the 1693 - its individual injection pumps and precombustion chambers foul gradually, and lab trends catch fuel dilution or coolant intrusion before a rocker box leak turns into a bearing problem. Test coolant additive concentration on a fixed schedule; the wet cylinder liners pit fast once additive levels drop. Log turbocharger boost pressure against a known-good baseline at rated rpm to catch turbo fade early, and track fuel filter delta-P since every cylinder's pump depends on clean supply.
Corrective & common repairs
Expect oil seepage at the rocker box covers and front/rear timing covers - chronic weak points on this engine. Check the quill drive linking the cam gear train; it can twist under load and throw valve timing off before symptoms show at idle. Inspect the air compressor mounting bracket for fatigue cracks, a known failure point, and watch for stripped valve-set ratchet heads during lash adjustment. On 1693TA units, idle surge or misfire below 600 rpm usually traces to uneven fuel delivery or timing drift, not the turbo.
Overhaul & rebuild points
Because the 1693 shares its crankshaft and connecting rods with the 3406, rebuilders sometimes cross-reference bottom-end components between the two - verify fitment before assuming interchange. At inframe, reseal the wet cylinder liners and recheck bore wear, and overhaul the injection pump set and precombustion chambers as a matched group rather than cylinder by cylinder, since mismatched pumps unbalance combustion. Rebuild the turbocharger center section on condition, not mileage. Sourcing detail parts is the real bottleneck, since factory support ended decades ago.
Seasonal & environment servicing
Cold starts rely on glow plugs threaded into the precombustion chambers under the rocker covers, not ether - injecting starting fluid into this precup design can blow out the chamber wall. Follow a preheat-and-crank cycle rather than forcing longer cranks in freezing weather. In hot climates or sustained high-load work, top up coolant additive levels more often since heat cycling accelerates liner cavitation, and recheck turbo boost lines and clamps after temperature extremes work fittings loose.
1693 common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 1S-9547 | Transfer | Lubrication service | Check fitment → |
| 9L-3951 | Oil Filter Assembly | Lubrication service | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
1693 attachments & work tools
Power ratings/configurations
Sold as the 1693T (non-aftercooled, roughly 325 hp at 2100 rpm) and 1693TA (turbocharged-aftercooled, ranging from about 375 hp up to 425 hp at 2100 rpm depending on rating). Torque peaks run roughly 1145-1565 N·m (845 to 1155 lb-ft) across the TA ratings; exact figures vary by rating plate and fuel setting.
Aftercooling arrangement
Offered as non-aftercooled (T) or turbocharged-aftercooled (TA); aftercooling was the main factory route to the higher horsepower ratings in this family.
Retarder (Brakesaver)
Because the precombustion-chamber design ruled out a conventional compression/exhaust engine brake, Caterpillar offered its own hydraulic retarder, marketed as the Brakesaver, as a factory option on this engine line, with automatic or manual control groups.
Fan drive
Adjustable/thermostatic fan drive options were available for this engine family to suit cooling needs across truck chassis and duty cycles; exact fan drive option fitted varies by chassis builder installation.
Accessory mounting (alternator, air compressor, starter)
Engine-driven alternator, air compressor, and starter mounts follow the truck-engine accessory layout typical of this era; the air compressor mounting point is commonly noted as a durability weak spot in service discussions for this engine, so inspect and support it during rebuilds.
Chassis application
Factory-fitted primarily in on-highway heavy-duty trucks (notably Autocar and similar Class 8 chassis, plus Freightliner, Peterbilt, and Kenworth conventional and cabover tractors) of the mid-1970s; not offered in Cat construction/earthmoving machines, so no excavator-, loader-, or dozer-style hydraulic work-tool couplers or quick-coupler systems apply to this model.
All 1693 assemblies by section
Every catalogued assembly group for the Caterpillar 1693. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Attachments
9l1700 Air Cleaner Group--Single Stage--Dry Type
| 9L***00 | Air Cleaner Group | 1 |
9l2016 Air Cleaner Group--Two Stage--Heavy Duty--Dry Type
| 9L***16 | Air Cleaner Group | 1 |
9l1694 Air Inlet Elbow Group--Turbocharger
| 9L***94 | Air Inlet Elbow Group | 1 |
9l5058 Alternator Group--12 Volt, 62 Ampere
| 9L***58 | Alternator Group | 1 |
9l5682 Alternator Group--12 Volt, 62 Ampere
| 9L***82 | Alternator Group | 1 |
9l2421 Auxiliary Double Drive Pulley Group
| 9L***21 | Auxiliary Double Drive Pulley Group | 1 |
9l2420 Auxiliary Single Drive Pulley Group
| 9L***20 | Auxiliary Single Drive Pulley Group | 1 |
Electric Starting (24 Volt) And Alternator (12 Volt)--Type 2
Electric Starting (24 Volt) And Alternator (12 Volt)--Type 1
Electric Starting (24 Volt) And Alternator Mounting (9l5130 N/S)
| 9L***30 | Electric Starting And Alternator Mounting | 1 |
Electric Starting (24 Volt) And Alternator Mounting (9l3934 N/S)
| 9L***34 | Electric Starting And Alternator Mounting | 1 |
9l5062 Electric Starting Motor Group--24 Volt
| 9L***62 | Electric Starting Motor Group | 1 |
9l2054 Exhaust Elbow Adapter Group--6 Inch
| 9L***54 | Exhaust Elbow Adapter Group | 1 |
9l2454 Exhaust Elbow Group--6 Inch
| 9L***54 | Exhaust Elbow Group | 1 |
9l6372 Fan Drive Group
| 9L***72 | Fan Drive Group | 1 |
9l6075 Fan Drive Group (1 : 1 Ratio)
| 9L***75 | Fan Drive Group | 1 |
3n7194 Fan Drive Group--Factory Installation
| 3N***94 | Fan Drive Group | 1 |
9l6077 Fan Drive Group (1 : 1 Ratio)
| 9L***77 | Fan Drive Group | 1 |
9l6374 Fan Drive Group
| 9L***74 | Fan Drive Group | 1 |
9l6375 Fuel Filter Group--Secondary
| 9L***75 | Fuel Filter Group | 1 |
9l6376 Fuel Filter Group--Secondary
| 9L***76 | Fuel Filter Group | 1 |
9l2445 Hydraulic Pump Drive Group--Rear
| 9L***45 | Hydraulic Pump Drive Group | 1 |
9l4976 Hydraulic Pump Drive Group--Rear
| 9L***76 | Hydraulic Pump Drive Group | 1 |
9l5876 Hydraulic Pump Drive Group
| 9L***76 | Hydraulic Pump Drive Group | 1 |
Name Plates And Transfers
| 1H***40 | Transfer; Safety On Dash Or Guards When Used | 1 |
| 1M***98 | Transfer; Filter Instructions On Oil Filter Cover | 1 |
| 1S***47 | Transfer; Crankcase Instructions On Oil Filter Or Open Space Near Oil Filter | 1 |
9l2506 Oil Filler Adapter Group
| 9L***06 | Oil Filler Adapter Group | 1 |
9l3748 Oil Filter Group--Remote Mounted
| 9L***48 | Oil Filter Group | 1 |
9l6377 Oil Level Gauge Group
| 9L***77 | Oil Level Gauge Group | 1 |
9l1616 Oil Level Gauge Group
| 9L***16 | Oil Level Gauge Group | 1 |
9l2360 Oil Pan Group--Front Sump
| 9L***60 | Oil Pan Group | 1 |
2n2489 Manual Shut-Off Group
| 2N***89 | Shut-Off Group-Manual | 1 |
Diesel Engine
Accessory Drive (9l4711 N/S)
| 9L***11 | Accessory Drive | 1 |
Aftercooler (9l1543 N/S)
| 9L***43 | Aftercooler; Aftercooler Group | 1 |
9l1700 Air Cleaner Group--Single Stage--Dry Type
| 9L***00 | Air Cleaner Group | 1 |
Air Compressor And Drive (9l1634 N/S)
| 9L***34 | Air Compressor And Drive | 1 |
Air Compressor And Drive
Air Compressor And Drive--Type 1
Air Compressor And Drive--Type 2
Air Compressor And Drive (9l5584 N/S)
| 9L***84 | Air Compressor And Drive | 1 |
9l1414 Air Compressor Assembly
| 9L***14 | Air Compressor Assembly | 1 |
9l1414 Air Compressor Assembly--Type 2
| 9L***14 | Air Compressor Assembly | 1 |
9l5369 Air Compressor Assembly
| 9L***69 | Air Compressor Assembly | 1 |
9l4092 Air Compressor Assembly
| 9L***92 | Air Compressor Assembly | 1 |
9l1564 Alternator Assembly--12 Volt, 60 Ampere--Type 2
| 9L***64 | Alternator Assembly | 1 |
9l1564 Alternator Assembly--12 Volt, 60 Ampere--Type 1
| 9L***64 | Alternator Assembly | 1 |
9l1841 Alternator Assembly--12 Volt, 62 Ampere--Side View--Type 2--Part 1 Of 2
| 9L***41 | Alternator Assembly | 1 |
9l1841 Alternator Assembly--12 Volt, 62 Ampere--End View--Type 1--Part 2 Of 2
| 9L***41 | Alternator Assembly | 1 |
9l1841 Alternator Assembly--12 Volt, 62 Ampere--Side View--Type 1--Part 1 Of 2
| 9L***41 | Alternator Assembly | 1 |
9l1841 Alternator Assembly--12 Volt, 62 Ampere--End View--Type 2--Part 2 Of 2
| 9L***41 | Alternator Assembly | 1 |
Automatic Timing Advance Drive
Breather (9l1628 N/S)
| 9L***28 | Breather | 1 |
Breather (9l5397 N/S)
| 9L***97 | Breather | 1 |
Camshaft
Camshaft Drive
Camshaft Drive (9l4768 N/S)
| 9L***68 | Camshaft Drive | 1 |
Camshaft Drive (9l5400 N/S)
| 9L***00 | Camshaft Drive; Camshaft Drive Group | 1 |
Camshaft (9s737 N/S)
| 9S***37 | Camshaft Group; Camshaft Group | 1 |
3s9546 Connecting Rod And Piston Group--6 Required
| 3S***46 | Connecting Rod And Piston | 1 |
8s813 Connecting Rod And Piston Group--6 Required
| 8S***13 | Connecting Rod And Piston; Connecting Rod And Piston Group | 1 |
9m4178 Connecting Rod And Piston Group--6 Required
| 9M***78 | Connecting Rod And Piston | 1 |
2p412 Connecting Rod And Piston Group--6 Required
| 2P***12 | Connecting Rod And Piston Group | 1 |
2s4522 Connecting Rod And Piston Group--6 Required
| 2S***22 | Connecting Rod And Piston Group | 1 |
Crankshaft And Damper
Crankshaft Bearing Replacement
Crankshaft Bearing Replacement Groups
9s7536 Crankshaft Replacement Gear Group--Field Installation
| 9S***36 | Crankshaft Replacement Gear Group | 1 |
9s3042 Crankshaft Seal Group
| 9S***42 | Crankshaft Seal Group | 1 |
Cylinder Block And Covers--End View--Part 2 Of 2
Cylinder Block And Covers--Side View--Part 1 Of 2
Cylinder Block And Covers (9l5391 N/S)--Side View--Part 1 Of 2
| 9L***91 | Cylinder Block And Covers | 1 |
Cylinder Block And Covers (9l5391 N/S)--End View--Part 2 Of 2
| 9L***91 | Cylinder Block And Covers | 1 |
Cylinder Block And Covers (9l5160 N/S)--End View--Type 1--Part 2 Of 2
| 9L***60 | Cylinder Block And Covers | 1 |
Cylinder Block And Covers (9l5160 N/S)--End View--Type 2 - Part 2 Of 2
| 9L***60 | Cylinder Block And Covers | 1 |
Cylinder Block And Covers (9l5160 N/S)--Side View--Type 2--Part 1 Of 2
| 9L***60 | Cylinder Block And Covers | 1 |
Cylinder Block And Covers (9l5390 N/S)--End View - Part 2 Of 2
| 9L***90 | Cylinder Block And Covers | 1 |
Cylinder Block And Covers (9l5390 N/S)--Side View - Part 1 Of 2
| 9L***90 | Cylinder Block And Covers | 1 |
Cylinder Block And Covers (9l5160 N/S)--Side View--Type 1--Part 1 Of 2
| 9L***60 | Cylinder Block And Covers | 1 |
9l5779 Cylinder Block And Covers Group--Side View--Factory Installation - Part 1 Of 2
| 9L***79 | Cylinder Block And Covers Group | 1 |
9l5779 Cylinder Block And Covers Group--End View--Factory Installation - Part 2 Of 2
| 9L***79 | Cylinder Block And Covers Group | 1 |
Cylinder Block Assembly (9l4859 N/S)
| 9L***59 | Cylinder Block Assembly | 1 |
2s1803 Cylinder Block Assembly
| 2S***03 | Cylinder Block Assembly | 1 |
Cylinder Head And Valve Mechanism--End View - Part 2 Of 2
Cylinder Head And Valve Mechanism (9l5389 N/S)--End View--Part 2 Of 3--Type 1
| 9L***89 | Cylinder Head And Valve Mechanism; Cylinder Head And Valve Mechanism Group | 1 |
Cylinder Head And Valve Mechanism (9l5389 N/S)--Top View--Part 3 Of 3--Type 2
| 9L***89 | Cylinder Head And Valve Mechanism; Cylinder Head And Valve Mechanism Group | 1 |
Cylinder Head And Valve Mechanism (9l5161 N/S)--Top View--Part 3 Of 3--Type 2
| 9L***61 | Cylinder Head And Valve Mechanism | 1 |
Cylinder Head And Valve Mechanism--End View--Part 2 Of 3
Cylinder Head And Valve Mechanism--Top View--Part 3 Of 3
Cylinder Head And Valve Mechanism (9l4766 N/S)--Side View--Part 1 Of 2
| 9L***66 | Cylinder Head And Valve Mechanism | 1 |
Cylinder Head And Valve Mechanism (9l5161 N/S)--Side View--Part 1 Of 3--Type 2
| 9L***61 | Cylinder Head And Valve Mechanism | 1 |
Cylinder Head And Valve Mechanism (9l5161 N/S)--End View--Part 2 Of 3--Type 1
| 9L***61 | Cylinder Head And Valve Mechanism | 1 |
Cylinder Head And Valve Mechanism (9l5161 N/S)--End View--Part 2 Of 3--Type 2
| 9L***61 | Cylinder Head And Valve Mechanism | 1 |
Cylinder Head And Valve Mechanism--Side View - Part 1 Of 2
Cylinder Head And Valve Mechanism (9l5389 N/S)--Top View--Part 3 Of 3--Type 1
| 9L***89 | Cylinder Head And Valve Mechanism; Cylinder Head And Valve Mechanism Group | 1 |
Cylinder Head And Valve Mechanism (9l4766 N/S)--End View--Part 2 Of 2
| 9L***66 | Cylinder Head And Valve Mechanism | 1 |
Cylinder Head And Valve Mechanism (9l5389 N/S)--Side View--Part 1 Of 3--Type 1
| 9L***89 | Cylinder Head And Valve Mechanism; Cylinder Head And Valve Mechanism Group | 1 |
Cylinder Head And Valve Mechanism (9l5389 N/S)--Side View--Part 1 Of 3--Type 2
| 9L***89 | Cylinder Head And Valve Mechanism; Cylinder Head And Valve Mechanism Group | 1 |
Cylinder Head And Valve Mechanism (9l5161 N/S)--Side View--Part 1 Of 3--Type 1
| 9L***61 | Cylinder Head And Valve Mechanism | 1 |
Cylinder Head And Valve Mechanism--Side View--Part 1 Of 3
Cylinder Head And Valve Mechanism (9l5389 N/S)--End View--Part 2 Of 3--Type 2
| 9L***89 | Cylinder Head And Valve Mechanism; Cylinder Head And Valve Mechanism Group | 1 |
Cylinder Head And Valve Mechanism (9l5161 N/S)--Top View--Part 3 Of 3--Type 1
| 9L***61 | Cylinder Head And Valve Mechanism | 1 |
Cylinder Head And Valve Mechanism (9l5402 N/S)--Side View--Type 1--Part 1 Of 2
| 9L***02 | Cylinder Head Group; Cylinder Head And Valve Mechanism Group | 1 |
Cylinder Head And Valve Mechanism (9l5402 N/S)--End View--Type 2--Part 2 Of 2
| 9L***02 | Cylinder Head Group; Cylinder Head And Valve Mechanism Group | 1 |
Cylinder Head And Valve Mechanism (9l5402 N/S)--Side View--Type 2--Part 1 Of 2
| 9L***02 | Cylinder Head Group; Cylinder Head And Valve Mechanism Group | 1 |
Cylinder Head And Valve Mechanism (9l5402 N/S)--End View--Type 1--Part 2 Of 2
| 9L***02 | Cylinder Head Group; Cylinder Head And Valve Mechanism Group | 1 |
1m5061 Tachometer Drive Group
| 1M***61 | Drive Group-Tachometer | 1 |
4l5789 Tachometer Drive Group
| 4L***89 | Drive Group-Tachometer | 1 |
9l2921 Exhaust Elbow Group
| 9L***21 | Elbow Group-Exhaust | 1 |
Electric Starting (24 Volt) And Alternator (12 Volt)
9l2200 Electric Starting Motor Assembly--24 Volt--Part 2 Of 2--Type 2
| 9L***00 | Electric Starting Motor Assembly | 1 |
9l2200 Electric Starting Motor Assembly--24 Volt--Part 1 Of 2--Type 1
| 9L***00 | Electric Starting Motor Assembly | 1 |
9l2200 Electric Starting Motor Assembly--24 Volt--Part 2 Of 2--Type 1
| 9L***00 | Electric Starting Motor Assembly | 1 |
9l2200 Electric Starting Motor Assembly--24 Volt--Part 1 Of 2--Type 2
| 9L***00 | Electric Starting Motor Assembly | 1 |
Engine Support--Front
Exhaust Manifold (9l1669 N/S)
| 9L***69 | Exhaust Manifold; Exhaust Manifold Group | 1 |
Fan Drive (9l2521 N/S)
| 9L***21 | Fan Drive | 1 |
Fan Drive (9l1637 N/S)
| 9L***37 | Fan Drive | 1 |
Fan Drive (9l589 N/S)
| 9L***89 | Fan Drive | 1 |
9l5599 Fan Drive Group
| 9L***99 | Fan Drive Group; Fan And Drive Group | 1 |
9l4308 Fan Mounting Group--Field Installation
| 9L***08 | Fan Mounting Group | 1 |
9l4307 Fan Mounting Group
| 9L***07 | Fan Mounting Group | 1 |
8h7204 Primary Fuel Filter Group
| 8H***04 | Filter Group-Fuel | 1 |
Flywheel
Fuel Filter (9l4617 N/S)
| 9L***17 | Fuel Filter; Fuel Filter Group | 1 |
Fuel Filter
2s2882 Primary Fuel Filter Group
| 2S***82 | Fuel Filter Group | 1 |
Fuel Injection Valves And Lines (9l4878 N/S)
| 9L***78 | Fuel Injection Valves And Lines | 1 |
Fuel Injection Valves And Lines
1p2297 Fuel Priming Pump Assembly
| 1P***97 | Fuel Priming Pump Assembly | 1 |
9s8022 Fuel Priming Pump Assembly
| 9S***22 | Fuel Priming Pump Assembly | 1 |
8s6836 Fuel Priming Pump Group
| 8S***36 | Fuel Priming Pump Assembly | 1 |
9l1761 Fuel Priming Pump Group
| 9L***61 | Fuel Priming Pump Group | 1 |
Fuel Pump Housing
Fuel Pump Housing And Governor
8s5174 Fuel Pump Housing Group
| 8S***74 | Fuel Pump Housing Group | 1 |
8s5095 Fuel Ratio Control Group
| 8S***95 | Fuel Ratio Control Group | 1 |
3s8306 Fuel Transfer Pump Group
| 3S***06 | Fuel Transfer Pump Group | 1 |
9l5276 Fuel Transfer Pump Group
| 9L***76 | Fuel Transfer Pump Group | 1 |
5m6488 Fuel Transfer Pump Group
| 5M***88 | Fuel Transfer Pump Group | 1 |
7s5445 Fuel Transfer Pump Group
| 7S***45 | Fuel Transfer Pump Group | 1 |
Gasket Kits
| 1P***59 | Diesel Engine Complete | 0 |
| 1P***60 | Valve Grinding | 0 |
| 2S***59 | Diesel Engine Complete | 0 |
Glow Plugs--12 Volt
Glow Plugs (9l1692 N/S)--12 Volt
| 9L***92 | Glow Plugs; Glow Plug Group | 1 |
Governor Control (9l5210 N/S)
| 9L***10 | Governor Control | 1 |
Governor Control
Governor Control (9l1650 N/S)
| 9L***50 | Governor Control | 1 |
9l4615 Governor Group--Part 1 Of 2
| 9L***15 | Governor Group | 1 |
9l1546 Governor Group--Part 2 Of 2
| 9L***46 | Governor Group | 1 |
9l4615 Governor Group--Part 2 Of 2
| 9L***15 | Governor Group | 1 |
9l1546 Governor Group--Part 1 Of 2
| 9L***46 | Governor Group | 1 |
Governor Torque Spring
9l5658 Governor Torque Spring Group
| 9L***58 | Governor Torque Spring Group | 1 |
6l2357 Manual Shut-Off Group
| 6L***57 | Manual Shut-Off Group | 1 |
Oil Cooler
Oil Filter
9l3951 Oil Filter Assembly
| 9L***51 | Oil Filter Assembly | 1 |
Oil Lines
Oil Lines (9l4767 N/S)
| 9L***67 | Oil Lines; Oil Lines Group | 1 |
Oil Pan (9l1590 N/S)
| 9L***90 | Oil Pan; Oil Pan Group | 1 |
Oil Pan
Oil Pump And Drive
9l1614 Oil Pump And Drive Group
| 9L***14 | Oil Pump And Drive Group | 1 |
9l2283 Oil Pump Assembly
| 9L***83 | Oil Pump Assembly | 1 |
2s308 Fuel Priming Pump Assembly
| 2S***08 | Pump As-Fuel Priming | 1 |
Rack Stop And Torque Spring (9l5179 N/S)
| 9L***79 | Rack Stop And Torque Spring; Governor Torque Spring Group | 1 |
Governor Torque Spring (9l5179 N/S)
| 9L***79 | Rack Stop And Torque Spring; Governor Torque Spring Group | 1 |
3n583 Solenoid Shut-Off Group--12 Volt
| 3N***83 | Shut-Off Group-Solenoid; Solenoid Shut-Off Group | 1 |
6l1923 Solenoid Shut-Off Group--12 Volt
| 6L***23 | Solenoid Shut-Off Group | 1 |
Starting Aid Switch (9l5059 N/S)
| 9L***59 | Starting Aid Group | 1 |
4m1812 Solenoid Switch Assembly--24 Volt
| 4M***12 | Switch As-Solenoid | 1 |
1p9181 Solenoid Switch Assembly
| 1P***81 | Switch As-Solenoid | 1 |
Tachometer Drive
9l5274 Tachometer Drive Group
| 9L***74 | Tachometer Drive Group | 1 |
9l5070 Tachometer Drive Group
| 9L***70 | Tachometer Drive Group | 1 |
9l5271 Tachometer Drive Group--Rear Mounted--Field Installation
| 9L***71 | Tachometer Drive Group | 1 |
9s9680 Governor Torque Spring Group
| 9S***80 | Torque Spring Group | 1 |
Turbocharger (9l1656 N/S)
| 9L***56 | Turbocharger; Turbocharger Group | 1 |
Turbocharger
2s1885 Turbocharger Assembly
| 2S***85 | Turbocharger Assembly | 1 |
2s9768 Turbocharger Assembly
| 2S***68 | Turbocharger Assembly | 1 |
8s6474 Turbocharger Assembly
| 8S***74 | Turbocharger Assembly | 1 |
8s5115 Variable Timing Drive Assembly
| 8S***15 | Variable Timing Drive Assembly | 1 |
Water Lines (9l2505 N/S)--Type 2
| 9L***05 | Water Lines; Water Lines Group | 1 |
Water Lines (9l2505 N/S)--Type 1
| 9L***05 | Water Lines; Water Lines Group | 1 |
Water Lines (9l2505 N/S)--Type 3
| 9L***05 | Water Lines; Water Lines Group | 1 |
9l1651 Water Lines Group--Side View - Part 2 Of 2
| 9L***51 | Water Lines Group | 1 |
9l1651 Water Lines Group--End View - Part 1 Of 2
| 9L***51 | Water Lines Group | 1 |
Water Pump And Drive
9l1515 Water Pump And Drive Group
| 9L***15 | Water Pump And Drive Group | 1 |
1693 serial number reference
The engine serial/data plate is mounted on the engine itself rather than a separate chassis frame plate, consistent with Caterpillar truck engines of this era, but the exact placement on the 1693 block/valve-cover area is not independently documented for this specific model - confirm placement against your unit or the 1693 service manual. The prefix is the first three characters (65B) followed by a sequential build number; the prefix identifies the engine model/design series, and the digits after it are the production sequence used to bracket early (65B1-65B781) vs late (65B782 and up) service-manual coverage.
| Prefix | Identifies | Notes |
|---|---|---|
| 65B | 1693 Truck Engine (1693T turbocharged, 1693TA turbocharged-aftercooled) | Single serial prefix covers the whole 1693 truck engine family, split into an early run (65B1-65B781) and a later run (65B782 and up) reflected in separate service manual volumes. Truck-adapted version of the D343 industrial/dozer engine: inline-6, 14.6 L (893 cu in), dual overhead cam, 4 valves per cylinder, individual injection pump per cylinder feeding a precombustion chamber. Non-aftercooled 1693T rated around 325 hp at 2100 rpm; aftercooled 1693TA rated roughly 375-425 hp at 2100 rpm, varies by rating/series. Introduced 1964; offered alongside the 3406 by the mid-1970s, with 1693 production tapering off sometime between 1976 and 1980 depending on configuration. Predecessor to the 3406. |
Frequently asked questions
What engine is the Caterpillar 1693?
The 1693 is the engine itself: a 14.6 L (893 cu in), six-cylinder, dual-overhead-cam diesel with a precombustion-chamber (indirect injection) design, an individual injection pump per cylinder, and a single turbocharger. Caterpillar offered it as the turbocharged-only 1693T and the turbocharged-aftercooled 1693TA, with ratings from roughly 270 to 425 hp depending on configuration and model year.
What is the operating weight of the Caterpillar 1693?
Reported dry engine weight ranges from about 1,460 to 2,175 kg (3,225-4,800 lb). The spread reflects differences between T and TA configurations and accessory fitment, so treat any single published figure as approximate and confirm against the specific unit.
What replaced the Caterpillar 1693?
The Caterpillar 3406 replaced the 1693 as Cat's on-highway flagship, taking over fully by 1977. The 3406 carried forward the 1693's bottom-end architecture, including a shared crankshaft and connecting rod design, while adding a factory engine brake option the 1693 never had.
What 1693 owners discuss
What wear items show up most on a 1693 - precombustion chambers, injector pump timing, twin-cam valve train, turbo?
The individual injection pump per cylinder is the item owners flag hardest: if one or two pump plungers drift out of timing sync with the rest, that cylinder runs noticeably hotter than its neighbors, and left unchecked that mismatch is what burns pistons and takes the whole engine down. Rack settings and pump timing should be checked against the engine's own arrangement number rather than a generic spec, since the 1693 spans several internal parts breaks. The twin overhead cam layout (separate inlet and exhaust cams, with the rear exhaust cam driven off the front one by a quill shaft) is mechanically simple and holds up well in service; on head work, resetting valve lash correctly at reassembly matters more than any single wear part - figures commonly cited run around 0.46 mm (0.018 in) intake and 0.76 mm (0.030 in) exhaust, though this varies by arrangement. On turbo differences, the 1693T (roughly 242 kW / 325 hp) ran a smaller turbo with no aftercooler, while 1693TA ratings (commonly 280-317 kW / 375-425 hp) added an aftercooler, a larger turbo, and different governor torque-spring calibration on a shared core block. Pushing a T-rated engine up to TA output isn't a simple rack adjustment - it can call for the larger turbo, different pistons, and a different pump camshaft, and mismatched combinations are exactly what burns a cylinder down. Have a shop experienced with 1693 pump timing verify rack settings and turbo/aftercooler matching before returning the engine to full load.
Does the 1693 smoke or burn oil, and what's usually behind it?
A low, uneven idle hunt - owners describe roughly a 50 rpm surge just under 600 rpm, with smoke that comes and goes - is commonly traced to worn governor flyweights that hang instead of moving freely rather than to a fuel or air problem. Genuine oil-consumption smoke on a high-hour, never-rebuilt engine points at worn valve guides or rings: worn guides let oil past into the intake and exhaust ports, and once wear is significant no additive stops it - only replacement does. A distinctive clattery, rattly idle note is characteristic of the precombustion-chamber mechanical injection design itself and isn't by itself a fault sign. Have a mechanic check governor flyweight movement and run a compression or leak-down test to separate a worn-governor surge from true oil burning before assuming a rebuild is needed.
What do owners report about 1693 oil pressure and the rear main bearing?
Reported oil pressure on some running engines sits on the low side of factory spec - one owner account cited roughly 138 kPa (20 psi) at idle and 276 kPa (40 psi) at rated speed, which experienced operators read as about 15-20 psi under where the engine should sit. The fix path discussed starts with checking the oil pump spring and plunger before resorting to shimming the pump. Separately, the rear main (thrust) bearing is called out by name as one that cracks on occasion, so it's worth a specific look on any engine with unknown history or high hours. Get actual oil pressure readings at idle and rated speed, plus a rear main bearing check, from a mechanic before trusting a used 1693 under sustained load.
Are there known cooling-system quirks specific to the 1693?
No widely repeated cooling-specific failure pattern shows up for this engine beyond ordinary diesel cooling maintenance - radiator condition, water pump impeller wear, and thermostat operation are the usual overheating culprits on any engine of this vintage and get checked the same way here. The one design-specific point worth noting is that TA-rated (aftercooled) versions add an extra heat-rejection path through the aftercooler core, so that core and its plumbing are worth including in a cooling-system inspection on aftercooled units, alongside the radiator and water pump. Have a mechanic pressure-test the cooling system and inspect the aftercooler (on TA-rated engines) as part of any pre-purchase or troubleshooting check.
How does a 1693 behave in cold weather starting?
As a precombustion-chamber design, the 1693 needs glow-plug heat to fire once temperatures drop - one owner running a 1693-powered plow truck reported it simply will not start in cold weather without warming the glow plugs first. Because ignition happens in the precombustion chamber rather than at an intake air heater grid, starting fluid sprayed into the intake doesn't contact the glow plugs the way it can on some newer engines, so ether is usable as a cold-start aid on this engine when dosed sparingly - short bursts into the intake while cranking, not a continuous spray. Confirm your specific truck's glow plug and starting-aid setup and the correct starting sequence with a mechanic before relying on ether in cold weather.
Are parts and rebuild kits for the 1693 still available today?
Parts are described by owners as obtainable but not cheap - shorthand in trucker forums is to have a healthy budget ready, since this engine has been out of Caterpillar's on-highway lineup for decades. Aftermarket heavy-duty rebuild suppliers still stock liner, piston, ring, bearing, and gasket kits along with individual components such as pumps, injectors, valve guides, and water pumps for the 1693/D343 engine family, so full rebuilds remain realistic. Confirm the engine's arrangement number before ordering, since owners note multiple internal parts breaks (spacer-plate variants and similar changes) across the production run that affect which parts fit a given serial range.
What should I check before buying a truck or chassis with its original 1693 still in it?
Pull the engine data plate and record the serial and arrangement number first - a shop needs this to pull correct rack and timing settings, since generic 1693 specs can be wrong for a given unit. Idle the engine and watch and listen for a low-rpm surge (roughly 50 rpm hunting near 600 rpm), which flags worn governor flyweights; check oil pressure at idle and at rated speed against spec; and ask about smoke history under load. Because individual-cylinder pump mistiming is what owners say kills these engines, ask whether the injection pumps have been synced or serviced recently and whether any single cylinder has run noticeably hotter than the rest. Confirm whether the unit is a T or TA rating and that the turbo, aftercooler (if equipped), and any past power upgrades match factory-documented combinations rather than an ad hoc rack turn-up. Given parts cost and the age of the design, budget for a rebuild as a real possibility rather than an edge case. Have a diesel shop experienced with mechanical Cat truck engines do a full pre-purchase inspection, including pump timing verification, before you commit.
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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