This is not Third Gen related but I swapped the engine in my friend's Chevy Van and now the transmission will not up shift. I have readjusted the TV cable according to the instructions in the Haynes manual. I pulled the cable all the way to the back and went full throttle. But still no go. The tranny will shift if i shift it manual from 1 to 2 and the 2 to 3. Any idea as what this could be, we have not touched the tranny at all and it was working perfect before we swapped the engine. Any help would be appreciated.

 

Found the problem tonight and thought i should share it. When we changed the engine, we moved the trany and the vacuum line at the back broke. Put new one and problem resolved.

 

Familiar problem with the vacuum actuated trannys. My father-in-law went to a transmission shop, they wanted to charge him 1,500 for a new tranny install.

I went over, replaced the vacuum line and it shifts like it used to. He went back to the shop and raised hell. Scared off some new customers sitting in the lobby area. He's pretty wild anyway.

Jim.