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SPM-HEP-4649 is the gear driven lubricating oil pump: a cast iron body with a drive gear, an idler gear and a gerotor element behind a cover plate. It is used on Cummins 4BT 3.9 engines. This aftermarket version is made to the same mounting and connections as the original, so it fits where the old one came off.
It replaces Cummins 4939585, Cummins 3937027, Cummins 5346492 and Cummins 3901384.
Sold as one unit. Check the number on your old part, or in the parts manual for your machine, before ordering.
| Part Type | Oil Pump |
| Replaces | Cummins 4939585 |
| Engine | Cummins 4BT 3.9 |
| Type | Gerotor, gear driven |
| Cross references | Cummins 3937027, Cummins 5346492, Cummins 3901384 |
| Fits | Cummins 4BT 3.9 and 4B 3.9 engines in excavators, loaders, generator sets and trucks |
| Condition | New, aftermarket |
| Stat. HS-Code | 841330 |
| Country of Manufacture | China |
Cummins machines
Check the part number on your old unit before ordering.
| Cummins Part No.(SPM Part No.) | Fits |
|---|---|
| 4939585(SPM-HEP-4649) | Cummins 4BT 3.9 and 4B 3.9 engines in excavators, loaders, generator sets and trucks |
| 3937027(SPM-HEP-4649) | Cummins 4BT 3.9 and 4B 3.9 engines in excavators, loaders, generator sets and trucks |
| 5346492(SPM-HEP-4649) | Cummins 4BT 3.9 and 4B 3.9 engines in excavators, loaders, generator sets and trucks |
| 3901384(SPM-HEP-4649) | Cummins 4BT 3.9 and 4B 3.9 engines in excavators, loaders, generator sets and trucks |
Low oil pressure
A warning light or low gauge reading with the right oil level and a good sender often means a worn oil pump.
Engine rebuilds
Fit a new oil pump whenever the engine is rebuilt or the bearings are changed. Worn gears undo a fresh rebuild.
Noise from the bottom end
Rattles at start-up while the pressure builds are a sign the pump is not priming quickly enough.
Fitting tips
Prime the pump with clean oil, fit new gaskets and O rings, and check the pickup screen before closing up.
We check what other aftermarket sellers charge for this same part. Their prices on the date we checked:
| Seller | Price | Checked |
|---|---|---|
| eBay (5 aftermarket sellers) | USD 74.00 to 181.15 | 31 Oct 2026 |
| KuduParts | USD 74.20 | 31 Oct 2026 |
| FridayParts | USD 80.01 | 31 Oct 2026 |
| Fab Heavy Parts | USD 117.77 | 31 Oct 2026 |
| MyMROmarts | USD 147.28 | 31 Oct 2026 |
| SINOCMP | USD 179.00 | 31 Oct 2026 |
| Spare Part Mart | USD 59.20 | Today |
Our price of USD 59.20 is 20% to 67% less than these sellers.
Found this part cheaper somewhere else? Send us the listing and we will beat it by 5% under our Price Beat Guarantee. Every order is also covered by our 30 day money back guarantee.
Yes, it was made for the Cummins 4BT 3.9, and 3 more listed under compatible equipment. Check the old oil pump is marked 4939585 or one of the cross references, because makers change parts between serial ranges.
On the Cummins 4BT 3.9, often 5,000 to 10,000 hours with clean fluid, much less with dirt or air in the system. It is usually changed on condition, not by hours.
Leaks from the seal or weep hole, noise or whining, overheating, or falling pressure or flow under load.
Clean them right back to metal and fit the new gasket or O-ring dry, unless the engine manual calls for sealant.
Most failures come from contamination, cavitation from a restricted inlet, or running low on fluid. Check the inlet and the fluid before fitting the new oil pump.
No. It is an aftermarket oil pump made to replace the Cummins 4939585. It is not made by the original manufacturer; the number only shows what it replaces.
Live rates for the quantity selected, delivered to your door. Confirmed at checkout.
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