So I have a weird issue.... transmission works fine... some rough shifts when it is cold but overall 270000 miles on truck I have had it last 50000 and i think it is original transmission... sometimes after I have been driving for awhile( converted into a mail delivery vehicle) the transmission will suddenly shift hard from 1st to 2nd and 2nd to 3rd.... like really hard gets worse n worse if I keep driving... however I have discovered it stops if I shut engine off for 10-15 seconds and restart it... seriously... it shifts fine again.... so my question is if there is anything else that could be the issue? U joints possibly??? Whenever I shift into reverse I hear I loud metal clunk.... there are some other things making me think u joints needs replacing anyways......thanks for any help...
Vehicle is 1999 gmc sierra 5.3 liter v8
If your transmission is shifting hard, then it's likely going out and you are going to have to get that thing replaced.
Yes I am aware of that.. but it started doing this 30000 Miles ago. And like I said it CONPLETLY STOPS after I shut off engine for 10 seconds and restart
I have gone over a month without it doing this... fluid is getting worn again and I think I may change again... last time I did it stopped for some time... today it started doing this again after driving forv4 hours of it not.... then shut off and restart and it is gone
Seems more likely to be some sensor or computer doodad... idw to change transmission and have whatever the issue is destroy another transmission... I drive this thing for hours and it shifts great...