TH350 Governor Shift Point Kit with Weights and Springs

This is a K018-style governor recalibration kit (part A44681-4K) for GM hydraulic automatics. It contains six steel governor weights, six calibration springs, two new weight pins with E-clip ends, and a replacement governor cover seal and gasket.

On a TH350 the governor is the only thing telling the valve body how fast the car is going, so any change to final drive ratio or tire diameter moves every upshift. Go to a numerically higher rear gear and the transmission shifts early and lazy; go taller or run bigger tires and it hangs in each gear. Swapping weights and springs is how you put the 1-2 and 2-3 points back where the engine makes power. The same kit also covers the TH350C 1969-1986, TH400 1965-1992, 700R4/4L60 1982-1993, TH250C 1980-1985 and 3L80 1992-1993.

On the bench: pull the governor cover, slide the governor out of the case, drive out the weight pins, and swap in the heavier or lighter weight and spring combination for the shift point you want. Heavier weights raise governor pressure sooner and bring shifts in earlier; stiffer springs push them later. Install the new pins with the E-clips, check that the weights swing freely with no bind, and reinstall with the new seal. Road test and adjust one step at a time.

Check the governor gear for chipped teeth and the sleeve bore for scoring while it is out. A worn governor or sticking weights will give erratic shift timing no matter what springs are in it.