700R4 Transmission
The TH700R4, or simply 700R4 as most refer to it as, is a four speed overdrive automatic transmission developed by General Motors. It is commonly swapped in place of the TH350 in older GMC and Chevrolet pickups, as having an overdrive transmission provides significant improvements in fuel economy and the swap does not sacrifice any of the TH350’s favorable characteristics.
The Turbo Hydra-Matic 700R4 transmission was introduced in 1982 as a replacement for the TH350. It features a 30% overdrive, which provided significant improvements in fuel economy over the three speed TH350, whose tallest gear was direct drive (1:1). Also beneficial, the 700R4 has a shorter 1st gear ratio (3.06 as opposed to 2.52). It’s heavier than the TH350, weighing in the ballpark of 200 lbs including the torque converter. In 1990, GM renamed the transmission the 4L60 - “4” for four speed, “L” for longitudinal (mounted), and “60” to represent a nominal GVWR of 6,000 lbs. The transmission continued to appear in a variety of GM vehicles, including 1/2 ton GMC/Chevrolet pickups, until 2012.
Brandon Sloan of Performance Transmissions in Greenville, SC
Ratios
| 1st | 2nd | 3rd | 4th | Reverse |
|---|---|---|---|---|
| 3.059 : 1 | 1.625 : 1 | 1.00 : 1 | 0.696 : 1 | 2.294 : 1 |
Specs
| Type | 4 speed, overdrive automatic transmission |
| RPO Code | MD8 |
| Applications | 1982 - 2012, various GMC, Chevrolet, and Buick applications |
| Cast material | Cast aluminum |
| Case length | 23.375” overall |
| Input spline | 27 spline to 1983 30 spline from 1984+ |
| Weight | ~200 lbs dry |
| Fluid type | ACDelco 10-9395, 10-9244 Dexron VI ATF |
| Fluid capacity | 8.8 - 11.4 quarts |
| Filter | GM 12360655 ACDelco Gold TF-235 |
| Pan gasket | GM 08654799 |
| Pan magnet | GM 29535617 |
| Pan bolts | 551683 |
| Speedometer adapter | GM 1565170 |
| Speedometer cable | GM 88959477 |
| Identification |  |
| Service interval | Replace transmission filter and fluid every 50,000 miles under normal conditions or every 30,000 miles under “severe service” condition. |