4T65E Pump 1983, remanufactured and ready to install. Fits the 4T65E. Ships fast from the USA.
If your Impala, Monte Carlo, LeSabre, Century or Grand Prix with the 4T65E takes a long breath before it drops into Drive, has lost line rise, or keeps logging P1811 on hot drives, and the pump checked out with a worn or scored slide, this is the piece you need rather than a whole pump. Despite the short listing name, this item is the front oil pump slide only, not a complete pump assembly. It is a remanufactured metal slide carrying industry number 84979, with GM interchange numbers 8656276, 8656272, 8662901 and 8662904, and a listed height of 17.968 mm. The 1983 in the title is the start of the application range: the slide is listed for the GM 440-T4 family from 1983-up, which includes the 4T60E and the 4T65E that grew out of it.
The 4T65E pump is a variable-displacement vane pump bolted to the valve body and channel plate under the side cover. The rotor and vanes spin inside the slide, and the slide is the part that makes the pump variable. At idle, spring force swings the slide toward maximum output so the clutches fill quickly. As line pressure builds, pressure pushes the slide back toward minimum so the pump stops wasting engine power. If the slide face is scored, its pivot is worn, or its height no longer holds the right end play against the pump body, oil leaks across the slide and the pump loses volume, most noticeably at hot idle. A slide that binds does the opposite: it cannot move at all, so line pressure has nowhere to go when the computer asks for more.
Check the fluid hot first, at the 180-200 F operating temperature, because a low level alone will make the pump cavitate and whine. Then run a line pressure test. Low pressure at idle that stays low points at pump clearances, the slide included. Normal idle pressure that will not rise can be a stuck slide, but it is just as often the boost valve, the EPC solenoid or a worn AFL valve bore in the channel plate, so rule those out using our 4T65E pump failure guide and the EPC solenoid guide. With the pump on the bench, Sonnax gives a slide end play range of 0.0003-0.0016 in. Over that range bleeds volume, and under it can bind the slide. Their shake test is simple: strip the pump, assemble the halves with only the slide inside, and shake it. You should hear the slide move.
The listing covers the GM 440-T4, 4T60E and 4T65E front pump slide, 1983-up. On the 4T65E side that means the 1997-2011 Buick, Chevrolet, Pontiac and Oldsmobile front-drive cars on our 4T65E parts page. Be careful with late units: in June 2002 GM changed the 4T65E from a two-piece to a three-piece pump, and pump parts between the two designs do not all interchange. Before you buy, measure your old slide height and compare it to 17.968 mm, and match it against the numbers above. If you are not sure, send us your year and VIN and we will check it.
The side cover has to come off and the pump has to come off the channel plate to reach the slide. Clean everything, check the pocket faces and rotor for scoring, and set slide end play with a straight edge and feeler gauge before torquing the pump halves. Inspect the pump shaft sleeve in the channel plate while you are there. If the pocket faces are scored, a complete 1997-2001 4T65E pump or the pump rotor support may be the better fix. Refill with Dexron VI and check the level hot.
| Fits | 4T65E 1983 |
| Part type | Pump |
| Condition | Remanufactured |
| Brand | GM |
| Reference | TH440 |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. It is the front oil pump slide only, industry number 84979. Use it when the pump body and rotor are good but the slide is worn, scored or out of end play spec. If the pocket faces are damaged, buy a complete pump instead.
The slide is listed for the whole 440-T4 family from 1983-up, which the 4T60E and 4T65E are part of. The 1983 marks where that family starts, not the year of your car.
GM changed to a three-piece pump in June 2002 and not every part interchanges. Measure your old slide height against 17.968 mm and compare part numbers, or send us your year and VIN before ordering.
It can contribute. A worn or binding slide lowers pump volume or stops line rise, which makes shifts take longer and can set P1811. The same code also comes from a worn AFL bore, boost valve or EPC solenoid, so test line pressure first.
Dexron VI. Fill, start the engine, then check the level at operating temperature, about 180-200 F.
