2011 tahoe first gear issue

[jhous09]

I am having a issue with my 2011 tahoe coming to a stop it seems to come out of first gear and go to neutral and then back into gear. Sometimes it will not go back into gear and will roll backwards until you rev up the engine then it slams into gear and drives fine until you come to a stop. I just had the transmission "rebuilt" but I'm pretty sure this is the same problem I was having before the rebuild. I asked him if he replaced the sprag and he said he "checked it" but didn't just replace it cause it's a 500 part. I'm just wondering if another sensor or component could be causing this issue before I just go buy a used transmission and swap it in to see if the problem goes away so that I can prove that this transmission guy ripped me off.

 

[Doubeleive]

I am having a issue with my 2011 tahoe coming to a stop it seems to come out of first gear and go to neutral and then back into gear. Sometimes it will not go back into gear and will roll backwards until you rev up the engine then it slams into gear and drives fine until you come to a stop. I just had the transmission "rebuilt" but I'm pretty sure this is the same problem I was having before the rebuild. I asked him if he replaced the sprag and he said he "checked it" but didn't just replace it cause it's a 500 part. I'm just wondering if another sensor or component could be causing this issue before I just go buy a used transmission and swap it in to see if the problem goes away so that I can prove that this transmission guy ripped me off.

you didn't get a warranty?

 

[Dustin Jackson]

@Doubeleive Sounds like money isn’t a concern to this guy lol

 

[Dustin Jackson]

@jhous09 What exactly did you have done to your transmission and how much did it cost you?

If you had a problem and you paid someone to fix it and they didn’t fix it…

 

[jhous09]

I have already pulled it twice and had him go through it again. He just keeps saying that there is nothing wrong with it but at this point I don't really trust the guys work.

 

[jhous09]

@jhous09 What exactly did you have done to your transmission and how much did it cost you?

If you had a problem and you paid someone to fix it and they didn’t fix it…

It was suppose to be a rebuild. I let the builder know exactly what it was doing. But come to find out he didn't replace some of the parts that I guess should be replaced when rebuilding a 6l80. He says he inspected them and nothing is wrong with it so I'm wondering if something else could be causing the problem or a part he didn't replace is the problem

 

[jhous09]

@Doubeleive Sounds like money isn’t a concern to this guy lol

At this point it's kind of not. I need this vehicle working correctly because it is the wife's car

 

[Dustin Jackson]

@jhous09 When you showed him that the problem was still happening did he say anything about fixing it?

 

[swathdiver]

I am having a issue with my 2011 tahoe coming to a stop it seems to come out of first gear and go to neutral and then back into gear. Sometimes it will not go back into gear and will roll backwards until you rev up the engine then it slams into gear and drives fine until you come to a stop. I just had the transmission "rebuilt" but I'm pretty sure this is the same problem I was having before the rebuild. I asked him if he replaced the sprag and he said he "checked it" but didn't just replace it cause it's a 500 part. I'm just wondering if another sensor or component could be causing this issue before I just go buy a used transmission and swap it in to see if the problem goes away so that I can prove that this transmission guy ripped me off.

This is often a problem with the TECHM solenoids that you can rebuild on your kitchen table without removing the transmission from the vehicle. That's what I think but let's ask our resident expert, Nick. @NickTransmissions

 

[NickTransmissions]

I am having a issue with my 2011 tahoe coming to a stop it seems to come out of first gear and go to neutral and then back into gear. Sometimes it will not go back into gear and will roll backwards until you rev up the engine then it slams into gear and drives fine until you come to a stop. I just had the transmission "rebuilt" but I'm pretty sure this is the same problem I was having before the rebuild. I asked him if he replaced the sprag and he said he "checked it" but didn't just replace it cause it's a 500 part. I'm just wondering if another sensor or component could be causing this issue before I just go buy a used transmission and swap it in to see if the problem goes away so that I can prove that this transmission guy ripped me off.

Sucks man, sorry to hear...I taught myself how to rebuild transmissions when the same thing happened to me when I was a teenager. Do you have a scanner capable of pulling/reading transmission-related DTCs?

Neutral in first could definitely be the sprag beginning to slip. I replace those each and every rebuild w/a GM AC Delco sprag assembly (Sonnax also makes a rebuild kit for them but I've never used it) - the assembly is around $125.00, not $500. I also replace the snap ring holding that spring in position on the back side of the center support on each overhaul (wonder if that was done at all).

If the TEHCM's fluid pressure switches are the problem, you're looking at TFP 1 as the possible culprit. If it's intermittently failing then you'll get a 'false neutral' condition in first gear followed by the transmission 'slamming' into gear. As @swathdiver mentioned, the diaphragms can sometimes either brake or get clogged up, impeding their ability to communicate information needed to control the transmission and they can be replaced on the bench w/the TEHCM out. Transgo sells a seals and diaphragm kit for those transmissions. The TEHCM should have been replaced with a compatable OEM TEHCM replacement unit.

Swapping in a Salvage Yard transmission:
You MUST verify that the TEHCM part number matches the part number on your TEHCM or have the TEHCM in the replacement 6L80 reprogrammed to match your vehicle's OS. If you don't do this, the replacement trans will never work right. You'll then need to do a fast adapt relearn to re-set the adapts to factory default before attempting to drive it. Go to a reputable salvage yard in your area if you're going to go this route - make sure you have a warranty so you can bring it back if it doesn't work.

You can check out my 6L80 Information thread (link in my signature) for more details around what parts and procedures need to accompany any rebuild of those units.