GM 6L80 Transmission Information Thread

[ilikemikes]

Amazing thread Nick! Bought a reman GM trans about 75k miles ago 09/2018. Have not done any maintenance on it. Yesterday started getting about a 2 sec delay when I shift into Drive. Thoughts please? About to go on vacay tomorrow. Could a filter and fluid resolve this issue? Thanks in advance.

 

[NickTransmissions]

Amazing thread Nick! Bought a reman GM trans about 75k miles ago 09/2018. Have not done any maintenance on it. Yesterday started getting about a 2 sec delay when I shift into Drive. Thoughts please? About to go on vacay tomorrow. Could a filter and fluid resolve this issue? Thanks in advance.

Thanks, Mike - appreciate the kind words!

I'd put a few more drive cycles to see if the condition persists...If so, drop the pan and inspect the bottom, that will be the easiest/fastest way to determine if the transmission is beginning to fail in some way as you'll see dark, burnt clutch material and/or sand-like material that could be either bronze/gold or silver in color...If anything like that is observed, put the pan back on with a couple bolts and yank it for overhaul and rent a car or SUV for your trip (If in doubt about your Tahoe at all, I'd suggest grabbing a rental).

Also inspect the filter neck. These have been known to crack from time to time, that can also cause everything from delayed engagements to no movement.

Is reverse also delayed by a sec or two or is it normal?

 

[ilikemikes]

Thanks for the quick response. Reverse is normal.

 

[NickTransmissions]

Thanks for the quick response. Reverse is normal.

Yea, I'd drive it a few more times locally, pay attn to the amount of time for each delayed engagement into drive, especially when fluid has warmed to normal operating temp. If there's a difference, that tells me soft parts are beginning to wear; if it's the same cold or hot, could be forward piston beginning to crack (common) or sprag beginning to roll over...Could also be #1 check ball beginning to get stuck in the plate or a TEHCM issue w/either one of the shift solenoids, the 1-2-3-4 clutch pressure control solenoid or pressure switches not communicating range position to the PCM quickly enough upon shift into Drive.

 

[ilikemikes]

Ok, thank you Nick! Will take the back up SUV (Acura 06 MDX) on vacation and keep the Tahoe local for now.

 

[ilikemikes]

Yea, I'd drive it a few more times locally, pay attn to the amount of time for each delayed engagement into drive, especially when fluid has warmed to normal operating temp. If there's a difference, that tells me soft parts are beginning to wear; if it's the same cold or hot, could be forward piston beginning to crack (common) or sprag beginning to roll over...Could also be #1 check ball beginning to get stuck in the plate or a TEHCM issue w/either one of the shift solenoids, the 1-2-3-4 clutch pressure control solenoid or pressure switches not communicating range position to the PCM quickly enough upon shift into Drive.

Nick, I called the top rated transmission shop here in Austin and this is the quote I got. They wanted me to get a diagnosis first but I explained the pause going into Drive is getting a longer and probably won't last much longer.
Thoughts on this? They are calling this service a full rebuild. They are not doing teardowns to fix specific parts. I don't really like the warranty. I think the reman I bought from GM came with 3yr/100k warranty.

2011 Tahoe 5.3 All stock Tow boat 6L80 Stg 1 $4000 plus tax, complete job Stg 1.5 rated 500HP $4400 plus tax, complete job *includes billet torque converter* 40k cooler would be recommended $350 installed Warranty 18months/18k miles Require 50% deposit

Thanks again for your input.

 

[NickTransmissions]

Nick, I called the top rated transmission shop here in Austin and this is the quote I got. They wanted me to get a diagnosis first but I explained the pause going into Drive is getting a longer and probably won't last much longer.
Thoughts on this? They are calling this service a full rebuild. They are not doing teardowns to fix specific parts. I don't really like the warranty. I think the reman I bought from GM came with 3yr/100k warranty.

2011 Tahoe 5.3 All stock Tow boat 6L80 Stg 1 $4000 plus tax, complete job Stg 1.5 rated 500HP $4400 plus tax, complete job *includes billet torque converter* 40k cooler would be recommended $350 installed Warranty 18months/18k miles Require 50% deposit

Thanks again for your input.

The price sounds about right though I'd want to confirm you're getting a new TEHCM from GM in that price. Otherwise, it may be a bit high. The warranty isn't too bad at all for an independent shop...You have to remember, General Motors is a multi-billion dollar company, the source company for all of these transmissions and has warranty reserve capital that would blow your mind so if an independent repair shop (a microscopic entity by comparison) is able to provide a 1-2 year warranty, that's very good provided they stand behind it. Another positive sign is that they don't do flat rate/'fix-it' type work and I'm the same way with these units...If I'm getting my grubby mitts on it, it's coming all apart and getting overhauled per page one of the thread (at minimum).

If possible, I'd want to know what they will be doing to the unit and what parts will be installed...Bump that up against the list of parts on page 1 to see if you have apples to apples. I'd also be curious as to what friction module they would be using...Given the name of the build, perhaps either Raybestos Stage One frictions, GPZ or Alto HE or Reds? Billet torque converter is a nice upgrade, esp for towing/hauling in the summer time as that's when heat will cause conventional tc covers to flex/warp if stressed enough...

 

[ilikemikes]

The price sounds about right though I'd want to confirm you're getting a new TEHCM from GM in that price. Otherwise, it may be a bit high. The warranty isn't too bad at all for an independent shop...You have to remember, General Motors is a multi-billion dollar company, the source company for all of these transmissions and has warranty reserve capital that would blow your mind so if an independent repair shop (a microscopic entity by comparison) is able to provide a 1-2 year warranty, that's very good provided they stand behind it. Another positive sign is that they don't do flat rate/'fix-it' type work and I'm the same way with these units...If I'm getting my grubby mitts on it, it's coming all apart and getting overhauled per page one of the thread (at minimum).

If possible, I'd want to know what they will be doing to the unit and what parts will be installed...Bump that up against the list of parts on page 1 to see if you have apples to apples. I'd also be curious as to what friction module they would be using...Given the name of the build, perhaps either Raybestos Stage One frictions, GPZ or Alto HE or Reds? Billet torque converter is a nice upgrade, esp for towing/hauling in the summer time as that's when heat will cause conventional tc covers to flex/warp if stressed enough...

Just getting back to this Nick, thank you sir! I will ask for some specifics. Was just talking to my neighbor (ex-mechanic now engineer), he thinks the Billet torque converter is over doing my stock engine and for the amount of towing I do. I tow my bass boat once a week 30 to 100 miles. Its maybe 3500lbs. The Tahoe is currently a little sluggish while towing the boat and would like some pep. Thoughts? Thanks again.

 

[S33k3r]

Just getting back to this Nick, thank you sir! I will ask for some specifics. Was just talking to my neighbor (ex-mechanic now engineer), he thinks the Billet torque converter is over doing my stock engine and for the amount of towing I do. I tow my bass boat once a week 30 to 100 miles. Its maybe 3500lbs. The Tahoe is currently a little sluggish while towing the boat and would like some pep. Thoughts? Thanks again.

Money says you are running a 3.42 gear ratio. What size tires are you running? I'm thinking smaller tires or a larger ratio, like 3.73.

 

[ilikemikes]

Money says you are running a 3.42 gear ratio. What size tires are you running? I'm thinking smaller tires or a larger ratio, like 3.73.

Stock engine and reman transmission. Roughly 33 in tires (LT305/55R/20)