Help 2009 tahoe with the 6l80e

[showard_14]

Looking for some info if a trans out of a 2008 tahoe work in my 2009 looking for a budget build recently picked up a 2009 tahoe with trans issues still has 1st and 2nd but slips in all other gears even reverse. Previous owner broke a line on it and was run low on fluid pulled pan and inspected it was a bunch of small shaving in pan. Has a code set in the tcm. For p0776 code

 

[Fless]

Welcome to TYF from Colorado! Moved you over here for better exposure.

 

[NickTransmissions]

Looking for some info if a trans out of a 2008 tahoe work in my 2009 looking for a budget build recently picked up a 2009 tahoe with trans issues still has 1st and 2nd but slips in all other gears even reverse. Previous owner broke a line on it and was run low on fluid pulled pan and inspected it was a bunch of small shaving in pan. Has a code set in the tcm. For p0776 code

If both vehicles have the same trans, it should work provided a fast adapt relearn is done assuming the trans in both is a 6l80e.

If the transmission in both vehicles is a 4l60e, they will not swap without a reprogramming as the tcm strategies changed with the elimination of the 3-2 control solenoid and external mlps on the 4L60Es in 2009.

If one has a 4L60 and the other has a 6l80e then they won’t swap at all without major work.

4.8L and 5.3L received the 4L60 and 6.0L received the 6L80.

Slipping in third and reverse is the 3-5-R drum apply fluid leaking at the welds on the base of the drum. Most common failure on those 6l units.

 

[swathdiver]

Looking for some info if a trans out of a 2008 tahoe work in my 2009 looking for a budget build recently picked up a 2009 tahoe with trans issues still has 1st and 2nd but slips in all other gears even reverse. Previous owner broke a line on it and was run low on fluid pulled pan and inspected it was a bunch of small shaving in pan. Has a code set in the tcm. For p0776 code

No, the 2008 has a 4-speed transmission and yours has a 6-speed transmission.

If the transmission has been filled to the correct level, with the correct fluid, and checked after shifting through all the gears while sitting still, it may resolve itself. Cold check fluid temperature is between 80-90 degrees on the dipstick. This gets you into the ballpark. Hot check is 158-200 degrees and is most accurate.

If that doesn't solve the problem, the likely culprit is the 3-5-R regulator valve sticking. This can be repaired from the bottom of the transmission, without removing it, if memory serves. Nick will correct me if I'm mistaken.

That code, P0776 could also be related to other problems which would require removal of the transmission from the vehicle and partial or complete disassembly depending on the issue.

That code limits the transmission to 2nd or 4th gear depending on what the speed sensor sees. Less than or greater than 1,400 rpms.

A GM remanufactured unit is about $5-6K installed and comes with a 3 year, 100K mile warranty. Live near Vegas? That's where Nick's shop is located.

 

[NickTransmissions]

No, the 2008 has a 4-speed transmission and yours has a 6-speed transmission.

If the transmission has been filled to the correct level, with the correct fluid, and checked after shifting through all the gears while sitting still, it may resolve itself. Cold check fluid temperature is between 80-90 degrees on the dipstick. This gets you into the ballpark. Hot check is 158-200 degrees and is most accurate.

If that doesn't solve the problem, the likely culprit is the 3-5-R regulator valve sticking. This can be repaired from the bottom of the transmission, without removing it, if memory serves. Nick will correct me if I'm mistaken.

That code, P0776 could also be related to other problems which would require removal of the transmission from the vehicle and partial or complete disassembly depending on the issue.

That code limits the transmission to 2nd or 4th gear depending on what the speed sensor sees. Less than or greater than 1,400 rpms.

A GM remanufactured unit is about $5-6K installed and comes with a 3 year, 100K mile warranty. Live near Vegas? That's where Nick's shop is located.

Slippage in 3rd and R in the 6L80/90 can possibly be 3-5-R boost, 3/5/r regulator valve or even a bad clutch pressure solenoid but more than likely it’s the drum itself that’s bad and code p0766 can be set if/when this begins to happen. See this TSB for details

If fluid’s dark, stinks etc that drum is no good and 3-5-r clutch is wasted…

Exhibit A

TSB

 

[Geotrash]

Slippage in 3rd and R in the 6L80/90 can possibly be 3-5-R boost, 3/5/r regulator valve or even a bad clutch pressure solenoid but more than likely it’s the drum itself that’s bad and code p0766 can be set if/when this begins to happen. See this TSB for details

If fluid’s dark, stinks etc that drum is no good and 3-5-r clutch is wasted…

Exhibit A
View attachment 397764View attachment 397765
TSB

Those frictions and steels look fine from here. Send it!

 

[swathdiver]

Slippage in 3rd and R in the 6L80/90 can possibly be 3-5-R boost, 3/5/r regulator valve or even a bad clutch pressure solenoid but more than likely it’s the drum itself that’s bad and code p0766 can be set if/when this begins to happen. See this TSB for details

If fluid’s dark, stinks etc that drum is no good and 3-5-r clutch is wasted…

Exhibit A
View attachment 397764View attachment 397765
TSB

Course I'm guessing from my chair, when the OP said it was run low on fluid and the code set, I went for the easy option. My thinking being those hard parts breaking and setting the code would come from age but am no transmission expert. I did stay a Holiday Inn Express a few times though!

Thanks Nick!

 

[NickTransmissions]

Course I'm guessing from my chair, when the OP said it was run low on fluid and the code set, I went for the easy option. My thinking being those hard parts breaking and setting the code would come from age but am no transmission expert. I did stay a Holiday Inn Express a few times though!

Thanks Nick!

YW, @swathdiver - these transmissions are actually fairly straightforward to work on for mechanically inclined folks, the problem is all the specialized tooling needed. Lots of it and expensive!