08 GMC sierra transmission problems

Tysonschulte · March 19, 2016

OK new on here and need help. I own a 2008 GMC sierra 5.3 ext. Cab and having tranny problems.ok so 55,000 miles ago my tranny locked in drive and would not release no matter what I did .reverse was drive neutral was drive and when in park was drive didn't matter what gear I was in it tryed to drive. So when I had it in park I tapped the gas then herd a loud bang ever since then a gears selections worked as normal.but its been very hesitant when put into gear takes like 20-30 sec to engage some days goes into gear normal no hesitation.fluids still red as red and slight burnt smell. Fluid and filter were changed right after I had the issue 55,000 miles ago.can anyone help me I don't like e hesitation and can not tow anything due to a gear gri ding noise in front of tranny when pulling hard.please need help!!!

txab · March 19, 2016

Off to a qualified transmission shop..................

No magic fix here

O_J_Simpson · March 19, 2016

If you have been having the issue for 55,000 miles, just keep driving until it fails. Why did you not use your 100k warranty before it expired?

Tysonschulte · March 20, 2016

Would of used the warranty but the truck had 120,000 miles on when it happened and rather not take it to a tranny shop.and if it fails that I don't have the money to drop in a new tranny looking to fix the problem before it fails and if it ever does.

WilliamBos · March 20, 2016

Take it to a trans shop or the dealer and specify DIAGNOSE ONLY. It will need hooked up to a scanner.

Tysonschulte · March 20, 2016

Had it hooked up to a scanner and NO codes

txab · March 20, 2016

Had it hooked up to a scanner and NO codes

What scanner? an off the shelf from local parts store? It won't read read trans codes. Only engine codes and maybe ABS codes.

Drive it 'till it blows if you can't afford to have it diagnosed. Either way you're looking at a full rebuild imho with what you describe.

WilliamBos · March 20, 2016

What scanner? an off the shelf from local parts store? It won't read read trans codes. Only engine codes and maybe ABS codes.

Drive it 'till it blows if you can't afford to have it diagnosed. Either way you're looking at a full rebuild imho with what you describe.

Exactly. Unless the scanner was a Tech 2 or came off a tool truck (Mac, Snap on, Matco) it wont read trans codes.

Tysonschulte · March 20, 2016

OK when it first happened took it too a shop no codes and they couldn't figure it out haven't taken it to a shop sinceit all first started 55,000 miles ago. But planning on taking it soon but was trying to get help on here first.and I was thinking it has something to do with torque converter because at 35-45mph the rpms will bounce but only when coasting

VipEnt · June 18, 2016

How's it going everybody I'm new to this form and I have a 2008 Chevy Silverado V8 5.3L E85 ethanol fuel flex as far as modifications I have KN cold air intake, Shorty headers, Flowmaster cats, flowmaster exhaust and 373 gears, i'm having issues with the transmission when I put it in drive its stuck in third gear and of course it's accelerating really slow and the indication light for when your in P R N D 3 2 1, it's not there and the truck ran the code for the EVap solenoid, I changed it and it showed me a code for the TCM I change that.... the truck runs again , had stopped for a while but I'm with the same problem the transmission is not shifting at all it's stuck in 3rd gear... when I put it in reverse the doors do lock but when I put it in park they do not unlock other than that everything else works fine.... Any help would be greatly appreciated... I DJ almost every single weekend and this has got me in a big mess... If I'm not using my farm truck to pull my trailer then I'm renting one and it's just not the same without my truck at all...