hey guys, my truck is starting to show her age as she passes over 200k. im having a problem with the overdrive in my transmission. for some reason it really does'nt want to engage unless i really romp on the gas and get it above at least 50 mph then sometimes it downshifts way too soon. is it new transmission time or is this a simple fix. i really cant fork out the dough for a new tranny right now so this is not fun.

 

This may be a good place to start.

https://www.dieseltruckresource.com/...ad.php?t=42003

 

Look in the sticky at the tps test procedure and make sure it is bad. There is a very good chance that the tps is causing your trouble.