[dbledsoe]

I replaced the transmission in my 94 K1500 with a GMC rebuilt tranny at 200,000 miles (about a year ago). I now have 220,000 miles and the transmission is acting funny - sometimes it will not downshift out of overdrive if you step on the gas or if the cruise control calls for more power. The rpms go way up (past redline if I let it) but it does not downshift. Of course it won't do it when I take it to ths shop -2 shops so far. Any suggestions I can give them? It is still under warranty, but I'm tired of taking it to the shop and not finding anything.

 

[OldDiesel]

When you take it in to the shop, is it all warmed up and acting funny when you drop it off? When you do drop it off, are you just leaving the keys and waiting for a call? Sounds like the issue you've got has to do with trans temps. Next time, make sure the truck (transmission) is good and warm, and when you get there, leave it running and take one of the techs/service writers for a drive. If you leave it and wait for them to do it, it probably won't get warm enough for it to act up.

 

[MN_Burbon]

I hate that I had the same problem with overdrive on my 95 with the original tranny at 187k, had it in the shop for 3 days, they drove it all over the place and were not able to find anything. I finally just took it home and for some reason it hasn't happened again since. (4 weeks)