Tranny not shifting

[blackjeep2002]

Hey all. I put a shift improver kit in my TH 400 on my 78 Cherokee. Everything was fine for a couple of days until I noticed a leak coming from the return line that comes out of the radiator. I fixed the leak and and it was ok for a while and then it decided not to shift out of first gear. I checked the level and added the required amount of fluid and it still does not want to shift out of first. Anyone have any ideas what to do or check? Could the governor be sticking because the fluid got gummy because the level went low? Thanks

[porkchop]

Did you check the vacum line going to the modulator? Mine fell off before and that was the cause of mine not shifting.

[Stolen76]

The return line problem could be co-incedence. If all else fails, drop your valve body again. Your instruction sheet should list out which one of those springs, and check balls is for the 1-2 shift. You could have a bad spring or a stuck check ball.

[gsmikie]

check the goroner for galling and the gear on the gov

[Spudz]

My Eagle with a TF727 relative, the TF998, has a similar problem, but it goes away after about 5 minutes of driving (or if I warm it up for a bit before starting out). It's pretty annoying to say the least, but as soon as it's all warmed up it works pretty much like it should except for dropping out of gear at some lights sitting still.

Not really an answer I guess, but if yours works when warmed up maybe it's something like my problem. I'm guessing maybe old rubber seals in there don't seal well enough until they warm up and expand... although if you just did a valve body upgrade then you're probably not affected so much by 'old rubber'.

[blackjeep2002]

I checked the governor and the nylon gear was trashed, so I put in a new one it still did not shift. So I pulled the governor again and the nylon gear was sheared right off!!!! Now it is going to a tranny shop to see if they can figure it out. It is too cold out to keep messing with it in my garage! Thanks for all of your responses, they really helped.