700R4 Pump 1987-93, remanufactured and ready to install. Fits the 700R4. Ships fast from the USA.
If your 1987 to 1993 Chevy or GMC pickup, Blazer, Suburban, Camaro, Corvette or Caprice has a 700R4 that whines with engine speed, is slow to pick up Drive or Reverse once it is hot, or slips under throttle with good fluid, the front pump is a prime suspect. This is a remanufactured complete pump assembly for the later auxiliary valve body 700R4: body, stator support and rotor group assembled as one unit, so you are not rebuilding a worn cover in the driveway.
This is the 74500B-series pump, interchange 77914E, built for the auxiliary valve body version of the 700R4. Body casting numbers listed for it end in 132, 303, 704 or 732, and the stator support castings end in 570, 596, 612 or 828. It is a direct replacement for the complete pump, not a rotor kit or a bare cover.
The 700R4 does not use the fixed gear pump of the TH350 and TH400. It uses a variable-displacement vane pump turned by the converter hub. Vanes ride in a rotor and push against a slide that pivots to change output: full volume at idle, less once the engine is spinning and the pressure regulator is satisfied. That oil becomes line pressure for every clutch and band, the TV and governor signals that time the shifts, converter charge and lube. On the 1987-up auxiliary valve body cases, the pump also feeds the circuits that run through that added valve body, which is why the later pump is not drilled the same as the early one.
The 700R4 is hydraulically controlled, so a bad pump does not set trouble codes. The 3-4 clutch burnout this transmission is known for is often blamed on the clutches when the real cause is low pressure from the pump or a misadjusted TV cable.
Check fluid level and condition, then put a gauge on the line pressure tap and read it at idle in Drive and Reverse, and again with the TV cable pulled. Low numbers that do not rise with TV point to the pump, a stuck slide or a cross leak in the cover. Our 700R4 pump failure symptoms guide walks through the slide, ring and vane checks, and the delayed engagement guide covers the other causes of a slow Drive or Reverse so you do not replace a good pump.
This pump fits the 1987-1993 700R4 with the auxiliary valve body, and it must go into an aux valve body transmission. GM added the auxiliary valve body partway through 1987, so an early-1987 unit may still be the non-aux design and needs the earlier pump instead. Before ordering, look for the auxiliary valve body bolted to the case and compare the casting numbers on your old pump to the ones above. If you are not sure, send us your year and VIN. The non-aux 700R4 pump for 1984-1987 covers the earlier cases, and the full 700R4 parts collection has everything else for this unit.
| Fits | 700R4 1987-93 |
| Part type | Pump |
| Condition | Remanufactured |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Only if your transmission has the auxiliary valve body. GM added it partway through 1987, so early-1987 units are non-aux and take the earlier pump. Look for the auxiliary valve body on the case or compare casting numbers before ordering.
The later units have a small auxiliary valve body bolted to the case in addition to the main valve body. Your old pump's body casting should end in 132, 303, 704 or 732 and the stator support in 570, 596, 612 or 828. Send us your year and VIN if you want a second check.
It is a complete remanufactured pump assembly, part 74500B series, interchange 77914E. If your pump body and cover are good and you only need rotor, slide and rings, a rotor kit is the cheaper repair.
Only if low pump output was the cause. A misadjusted TV cable, a leaking boost valve or a worn servo pin can also burn the 3-4 clutch, so check pressure and the TV cable before and after the install.
Dexron ATF. Current Dexron-VI is backward compatible with the older Dexron specs the 700R4 originally used.
A new front seal, pump gasket and O-ring at minimum. Inspect the converter hub, and if the clutches are burnt plan on a master rebuild kit.
