Hi, I just reinstalled my IP for umpteenth time fixing all my noob mistakes. No more leaks everything is right now except for some reason the shifting is even worse now. It won't shift into second on its own until its practically redlined unless I let off the gas. And then it will go into third the same way however when I letoff to let it shift and then press the accelerator again it instantly downshifts. What gives? Did I tweak some kind of linkage? Before now I had a similiar problem but it would always shift within an acceptable range however not right? How can I adjust all this? Should I just take it to a tranny shop?

 

sounds like you have the downshift linkage stuck in passing gear.

 

If you have a E4OD, you probably didn't adjust the tps.

 

with an 87 truck, it will be a C-6 trans

 

TPS=throttle position sensor= FIPL=fuel injection pump lever same thing. I would bet that is your issue mine did this and I couldnt afford one at the time I unpluged my rpm meter on the top of the IP gear housing it seemed to smooth the shifting not sure why but it worked. You should replace your FIPL asap or adjust it if you can not sure how though

 

guys, he has an 87 with a C-6. it don't have any of those sensors.
it has a throttle cable, a VRV, and a downshift linkage.

 

Oops, didn't see your truck in sig, but now I see it underneath your name.

 

oops sorry me either

 

That sounds totally plausible. Not sure how adjust it though or how it should be oriented. Which linkage is that? The grey bar that comes up to the IP from down by the tranny?

 

@TJC I see you posted the same question in the transmission forum about 7 years ago lol and no one ever replied. How did you resolve it?

 

The kickdown rod is the metal rod that connects the kickdown lever on the drivers side of the trans to the throttle linkage at the engine. Check that it is connected at both ends. If it is it is unlikely to be a problem.
It could be a vacuum problem. On the drivers side of the injector pump you should have a vacuum regulatory valve (VRV) with two small vacuum pipes connected to it. One pipe comes from the vacuum pump at the front of the engine, the other goes to the vacuum modulator on the trans. You need to check that these pipes are connected and are not kinked/leaking either at the VRV or at the trans.

 

how does the motor run? that could have a lot to do with it not shifting wright. in another threat you said how you removed the ip gear cover, that's not the way its done, because doing so it can be out of time by several teeth. the gear timing marks have to line up,you remove the ip only not the cover.you need to read up on how this is done!

 

correct the rod that comes up from the trans.
if it is stuck in the push down position, it will always want to downshift, and will not upshift until you let off the throttle
i never did completely.
i have the VRV adjusted a bit off, so it will rev real high before it shifts if i am standing on it.
if i am easy in the throttle it shifts fine.
since the truck is no longer a daily driver i said the heck with it and live with the way it is. the truck is now religated to life as a yard ornament- snow plow rig.

that was actually my first post on FTE i think.

 

My 88 and 89 dont have kick down bars/rods, they both have cables attached to throttle linkage with clips that lift up to move the cable. 89 460 c6, 88 351 c6

 

gas and diesel are completely different animals, and do not share any driveline parts besides the axles and transfer case.