Heavy duty 3-4 clutch pack for the GM 4L60E, 4L65E and 700R4: 9 Alto frictions, 10 steels, backing plate and snap ring to rebuild the 3-4 pack.
If your Silverado, Sierra, Suburban, Express, Savana or S10 pulls hard in first and second, then flares, slips or never really grabs third and fourth, the 3-4 clutch is the first place to look. This 057757B-style heavy duty pack (also cross-referenced to A74100CPK) replaces every plate in that clutch for the 700R4, 4L60E and 4L65E: 9 Alto frictions, 10 steels, a flat backing plate and a thin snap ring, so you build the pack with more friction surface instead of reusing heat-checked steels.
The 3-4 clutch sits in the input housing and drives the reaction sun gear in third and fourth. It applies on the 2-3 shift and stays on in fourth, which means it holds full engine torque at highway speed and under towing load. The factory pack runs only five or six frictions in many 700R4 and 4L60E housings, and the stock backing plate can flex, so the pack heats up, the plates distort and the clutch starts to slip. The Alto PowerPack idea is simple: thinner .062 in frictions and thinner steels let you fit more plates in the same drum, which spreads the apply energy over more lining and gives a smoother, more durable 2-3 shift.
Pull the pan first. Heavy black friction dust points to a clutch pack, while bright metal points to hard parts such as the sun shell or planetary. Then check line pressure: Sonnax traces most 3-4 burn-ups to low pressure or third-gear oil leaks in the circuit (pump, input housing seals, case and valve body), not to the plates themselves. Our 4L60E 3-4 clutch diagnosis guide walks through the order of tests, and the line pressure testing guide covers the gauge hookup.
The listing covers the 700R4, 4L60E and 4L65E from 1982 to 2014 in Chevrolet, GMC and Cadillac trucks, vans and SUVs with the 4.3L, 4.8L and 5.3L engines. The Alto instructions are written for the 700R4 and 4L60E; the 4L65E already ships with a seven-friction pack, so measure your housing parts before deciding on a stack-up. How many of the 9 frictions you actually use depends on your 3-4 apply ring: Alto says a V-6 ring measures 3.975 in and a V-8 ring 3.800 in, and the plate count changes with that height and with whether your housing has a stepped apply plate. If you are not sure which housing you have, send us your year and VIN before ordering. See every part for this unit on the 4L60E parts page.
For plate-count options beyond this pack, read our 3-4 friction count and upgrade guide.
| Position | 3rd and 4th clutch (3-4 clutch) |
| Contents | 9 Alto friction plates (tan), 8 special-thickness steels, 2 standard-thickness steels, 1 backing plate, 1 snap ring |
| Fits | 700R4, 4L60E, 4L65E, 1982-2014 |
| Interchange | 057757B, A74100CPK |
| Weight | 3.96 lb |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is listed for the 700R4, 4L60E and 4L65E from 1982 to 2014. The kit includes extra plates so you can build the right stack for your housing. Measure the 3-4 apply ring (3.975 in on V-6, 3.800 in on V-8 per Alto) and check for a stepped apply plate, then follow the matching stack-up.
Not always. Alto lists seven-friction builds for V-6 housings, eight frictions for most V-8 regular and heavy duty builds, and nine for V-8 performance builds. Leftover plates are normal.
Alto recommends .025 to .040 in between the top friction plate and the backing plate after air checking the pack several times.
Most often low line pressure or a third-gear oil leak at the pump, input housing seals or valve body. A heavy duty pack adds holding power, but fix the pressure loss too or the new plates will fail.
Dexron VI ATF. Soak the frictions in it before assembly and fill the transmission with it after the rebuild.
