Description
Genuine OEM rear crankshaft seal and wear sleeve kit from Cummins. The 4089543 seals the rear of the crankshaft against the rear main bearing housing on M11, ISM, QSM and L10 engines in rear engine power take-off (REPTO) configurations, preventing crankcase oil from leaking past the flywheel mounting flange. Cummins catalogs this part as a seal kit, so it includes the wear sleeve as well as the seal.
Signs You Need a New Rear Crankshaft Seal
- Oil leak between the engine and the transmission bell housing
- Wet, oil-coated flywheel or clutch friction surface
- Drips or oil pooling under the bell housing after parking
- Slipping clutch or transmission contamination caused by oil migration
- Oil consumption with no external leak found elsewhere on the engine
Specifications
| Manufacturer | Cummins (Genuine OEM) |
|---|---|
| Part Number | 4089543 |
| Part Type | Rear Crankshaft Seal and Wear Sleeve Kit |
| Engine Compatibility | Cummins M11, ISM, QSM, L10 |
| Configuration | REPTO (rear engine power take-off) |
| Position | Rear of crankshaft, flywheel side |
| Kit Contents | Rear crankshaft seal and wear sleeve |
Cross References
This part replaces or is equivalent to the following part numbers:
- Cummins: 4089543
Applications
This rear crankshaft seal kit fits the following Cummins engine families:
- Cummins M11 and ISM 11.0L
- Cummins QSM 11.0L industrial and off-highway
- Cummins L10 10.0L
Verify your engine serial number and configuration before ordering. This kit is for REPTO (rear engine power take-off) applications — related Cummins numbers 4089542 and 4089544 cover other clutch and REPTO combinations in the same family, so match your existing part number rather than the engine name alone. This kit does NOT fit ISX, ISX12, ISX15, X15, QSX or Signature engines; the rear crankshaft seal and spacer kit for those engines is Cummins 4965569. Inspect the crankshaft sealing surface for a wear groove during service, and use the L10/M11 family seal installer rather than the ISX tool.
