Help Needed! Transmission Won’t Shift Into Gear on My 1982 K10 350 Trans

Discussion Forum
1

I have a 1982 Chevy K10 that runs and drives absolutely like butter. It has about 150,000 miles, and the engine has had some upgrades. I drive it daily, making sure to at least start it and take it for a spin around the neighborhood. Everything was fine after an 8-mile trip this morning, but when I tried to go for a joyride later, the transmission wouldn’t shift into gear. I can change gears (reverse, neutral, drive, etc.), but the engine just revs as if it’s in park, with no RPM changes or shifts happening.

I checked everything—tightened and loosened bolts, inspected the trans pan after draining the fluid, and everything seemed normal. The gear shift column appears to be working properly as well. Interestingly, after turning the key off and rotating through the 4 high, 4 low, neutral, and back to 2 wheel, it worked briefly when I started it up and put it in reverse, but then it stopped again. I also have a Dakota digital gear selector unit connected to the trans pan, but I don’t think that’s causing the issue. Any ideas or solutions? I’m open to any suggestions, so please share your thoughts!

2

Check the vacuum going to the vacuum modulator. Also, check the kickdown cable adjustment, as it controls fluid pressure too.

3

Make sure the vacuum modulator hose is good. If you unplug it from the back of the transmission, you should feel a lot of vacuum. Plug it back in tight and check the intake manifold end too. You should be able to suck on it and hear a click from the modulator. Without proper vacuum, it won’t shift properly.

4

Thanks for the suggestions! I’ll check the vacuum modulator hose and make sure everything is sealed tight. I really want to get this fixed.

5

Also, check if you have a TH350, TH400, or a 700R4. The latter uses a throttle valve cable instead of a modulator. That could affect shifting as well.

6

Sounds like a classic issue with vacuum leaks or modulator failure. Make sure to test everything thoroughly and let us know how it goes!