Odd Transmission issue.

[Eyesquad]

Howdy. Havea 2012 Yukon SLT. Transmission went out at 254,000. Had a full rebuild done with solenoids, computer, converter, the whole nine yards. Picked it up and all seemed fine until I got in to rush hour traffic. When coming to a hord stop, the truck seems to go almost in to neutral. When you go to take off it's real sluggish and then bangs in to first. Took it back, no codes, shop couldn't get it to reproduce it. Drove it some more, same stuff. Took it back again got it to do it in front of the guy who had a scanner on the truck at the time, nothing came up on scanner. They went to dump the software out but it wouldn't let them. They had installed the late model software by mistake. Tricked it, dumped the software and installed the new software. Got it about 50 miles feeling fine, then right back to doing the same thing. It doesn't throw a code or show anything out of the ordinary on the scanner. I'm at a loss. I thought pressure problem or solenoid, but everything is new. New doesn't always equal good, but that's what hes going with atm. He thinks the throttle body is worn, but I can't see how that would cause the issue i'm seeing here. I also have 35's on it with stock gearing but not sure how that would cause the issue i'm feling.

Next step is to take it to Chevrolet and have the diagnose it.

If anyone has any ideas, please let me know. Thanks and apologies if I missed it in the search.

 

[89Suburban]

That blows.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me will chime in.

 

[Eyesquad]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me will chime in.

Thank you very much! I'll post up some photos tomorrow. I look forward to being here.

 

[LordWayback]

Howdy. Havea 2012 Yukon SLT. Transmission went out at 254,000. Had a full rebuild done with solenoids, computer, converter, the whole nine yards. Picked it up and all seemed fine until I got in to rush hour traffic. When coming to a hord stop, the truck seems to go almost in to neutral. When you go to take off it's real sluggish and then bangs in to first. Took it back, no codes, shop couldn't get it to reproduce it. Drove it some more, same stuff. Took it back again got it to do it in front of the guy who had a scanner on the truck at the time, nothing came up on scanner. They went to dump the software out but it wouldn't let them. They had installed the late model software by mistake. Tricked it, dumped the software and installed the new software. Got it about 50 miles feeling fine, then right back to doing the same thing. It doesn't throw a code or show anything out of the ordinary on the scanner. I'm at a loss. I thought pressure problem or solenoid, but everything is new. New doesn't always equal good, but that's what hes going with atm. He thinks the throttle body is worn, but I can't see how that would cause the issue i'm seeing here. I also have 35's on it with stock gearing but not sure how that would cause the issue i'm feling.

Next step is to take it to Chevrolet and have the diagnose it.

If anyone has any ideas, please let me know. Thanks and apologies if I missed it in the search.

Look up low sprag failure, often overlooked in rebuilds-Andrew

 

[LordWayback]

All you need is a few couple thousandths gashes and your transmission will act horrible , in fact it may have been the reason for the failure in the first place but new clutches/other parts made it grab enough to drive.

 

[swathdiver]

Howdy. Havea 2012 Yukon SLT. Transmission went out at 254,000. Had a full rebuild done with solenoids, computer, converter, the whole nine yards. Picked it up and all seemed fine until I got in to rush hour traffic. When coming to a hord stop, the truck seems to go almost in to neutral. When you go to take off it's real sluggish and then bangs in to first. Took it back, no codes, shop couldn't get it to reproduce it. Drove it some more, same stuff. Took it back again got it to do it in front of the guy who had a scanner on the truck at the time, nothing came up on scanner. They went to dump the software out but it wouldn't let them. They had installed the late model software by mistake. Tricked it, dumped the software and installed the new software. Got it about 50 miles feeling fine, then right back to doing the same thing. It doesn't throw a code or show anything out of the ordinary on the scanner. I'm at a loss. I thought pressure problem or solenoid, but everything is new. New doesn't always equal good, but that's what hes going with atm. He thinks the throttle body is worn, but I can't see how that would cause the issue i'm seeing here. I also have 35's on it with stock gearing but not sure how that would cause the issue i'm feling.

Next step is to take it to Chevrolet and have the diagnose it.

If anyone has any ideas, please let me know. Thanks and apologies if I missed it in the search.

Well, the Adapts should have been reset/done when first rebuilt and all that wrong software stuff seems odd but I profess not to know everything.

The dealership will put their scan tool on it and run diagnostics and maybe even remove the TECHM and test it out as well on the bench. Let's hope that it is not a hard parts issue as previously mentioned.

 

[LordWayback]

Only other thing mechanically besides lower sprag is L/R clutches but unless it’s a ghetto shop they should’ve done them too

 

[gpracer1]

My brothers 2012 tahoe is doing the same thing, even while I was in it with the Tech 2 . I couldnt find anything except solenoid 1 had a line that was switching between not ready or not reporting or something like that. From a stop you give it throttle and it revs a few hundred rpms then pops into gear and goes, instead of just taking off immediately. He just dropped it off at the trans shop yesterday......Ill let you know if there is any info. Me personally I would replace the #1 solenoid if its easy enough, havent looked into how hard that is.

 

[Doubeleive]

clean the MAF and throttle body, at 50 miles the relearn should be done, if it is still doing it then take it back to the shop that did the work, all we can do is guess