Can I put a 2013 6l80 into my 08 Yukon?

[Andrew Melvin]

Hello Everyone,

The transmission on my 08 Yukon XL Denali is finally showing its age. Reverse has been slipping for a while but can still push her around on level ground. A couple of days ago my wife was driving the kids home from town and it acted like it went into limp. When I got home and test drove I could not replicate. I have plans for a full donor vehicle overhaul/transplant but this came sooner than expected. I’ve found a 64k donor out of a 13 Denali (car-part.com and the salvage yard both had it mislabeled as a 2008, VIN verification shows 13.) I read on “yourmechanic.com” that the “internals, most importantly the control module” is not compatible for someone asking the same question. I’m wondering if this is correct or if this is the answer given to those less mechanically inclined to entice them to click the “find a local mechanic” button.

Long story short, does anybody know if the 2008 and 2013 are truly incompatible or would it just need to be reflashed? My plan is to use the HP Tuner MPV12+ and VCM Editor to save my the flash off my 08 and reload it onto the 13, if that is even possible.

Any insight is greatly appreciated. Thanks.

 

[swathdiver]

Hello Everyone,

The transmission on my 08 Yukon XL Denali is finally showing its age. Reverse has been slipping for a while but can still push her around on level ground. A couple of days ago my wife was driving the kids home from town and it acted like it went into limp. When I got home and test drove I could not replicate. I have plans for a full donor vehicle overhaul/transplant but this came sooner than expected. I’ve found a 64k donor out of a 13 Denali (car-part.com and the salvage yard both had it mislabeled as a 2008, VIN verification shows 13.) I read on “yourmechanic.com” that the “internals, most importantly the control module” is not compatible for someone asking the same question. I’m wondering if this is correct or if this is the answer given to those less mechanically inclined to entice them to click the “find a local mechanic” button.

Long story short, does anybody know if the 2008 and 2013 are truly incompatible or would it just need to be reflashed? My plan is to use the HP Tuner MPV12+ and VCM Editor to save my the flash off my 08 and reload it onto the 13, if that is even possible.

Any insight is greatly appreciated. Thanks.

I think you just need to flash the new transmission to your VIN and then do a Service Learn Adapts. Did you get the torque converter too? Make sure to space if properly and examine your flex plate for cracks.

 

[Andrew Melvin]

I think you just need to flash the new transmission to your VIN and then do a Service Learn Adapts. Did you get the torque converter too? Make sure to space if properly and examine your flex plate for cracks.

Im going to replace the torque converter with one made for towing by transtar. Glad you said something about the flex plate, I should probably have a new one on hand just in case. I can check Mitchell, but any quick specs on the proper spacing?

 

[swathdiver]

Im going to replace the torque converter with one made for towing by transtar. Glad you said something about the flex plate, I should probably have a new one on hand just in case. I can check Mitchell, but any quick specs on the proper spacing?

Sorry I do not recall. Precision Transmission (Youtube) talks about it a lot on his teardown videos and even shows us how to do it.

 

[Doubeleive]

I would imagine there is some electrical difference from 08 to 13 in which case you may need a adapter harness. I am just speculating since they did make some changes in 2010+
you might try digging around a bit more online and see what years are shown as compatible and then figure out why and what the differences are and if a adapter is needed or even made which they probably are if this is the case.

 

[Andrew Melvin]

I have been digging for hours the last 3 days. I haven’t been able to find anything talking about updates to what and when. I called the salvage yard today and told them to hold on the purchase until I verify. He, of course, assured me it would fit. I know it’ll fit, but will the computers be able to communicate? It would be nice if I could find a lower mileage something in my year range and just be done with it but I don’t want to spend 3 grand just to be right back in the same boat in 5 months.

 

[swathdiver]

I would imagine there is some electrical difference from 08 to 13 in which case you may need a adapter harness. I am just speculating since they did make some changes in 2010+
you might try digging around a bit more online and see what years are shown as compatible and then figure out why and what the differences are and if a adapter is needed or even made which they probably are if this is the case.

I have been digging for hours the last 3 days. I haven’t been able to find anything talking about updates to what and when. I called the salvage yard today and told them to hold on the purchase until I verify. He, of course, assured me it would fit. I know it’ll fit, but will the computers be able to communicate? It would be nice if I could find a lower mileage something in my year range and just be done with it but I don’t want to spend 3 grand just to be right back in the same boat in 5 months.

There are no physical differences in wiring, they all use the same 16-pin plug. There are incremental improvements every year of various internal components and dozens of different TECHMs. As long as the donor transmission came out of a 4x4 truck and not a Corvette it will work. Problems can arise by using the wrong TECHM, like putting your old one in the new transmission, maybe. Yours is 24275872 and the 2013s is 24275873. I do not know what the differences are.

Andrew, if you have to see it with your own eyes, go to Amazon and purchase Art Landeck's 6L80E Shops Notes and ATSGs 6L80 Techtran Manual.

If you are at the dealership or tried talking to the service writers, it is very likely they will have no idea. Drive around back and and find the transmission guys and ask them.

Go over to the Performance Trucks forum and or the LS1Tech forum and ask what exactly needs to be programmed when swapping in a donor transmission. Is it just the VIN or something more? I know the Service Fast Learn Adapts will need to be done with the scan tool. That's easy.

 

[skpyle]

...go to Amazon and purchase Art Landeck's 6L80E Shops Notes

Unfortunately, this is no longer listed on Amazon. Or even google. I would like to have a copy for my impending torque converter and front drum replacement.

 

[BG1988]

Hello Everyone,

The transmission on my 08 Yukon XL Denali is finally showing its age. Reverse has been slipping for a while but can still push her around on level ground. A couple of days ago my wife was driving the kids home from town and it acted like it went into limp. When I got home and test drove I could not replicate. I have plans for a full donor vehicle overhaul/transplant but this came sooner than expected. I’ve found a 64k donor out of a 13 Denali (car-part.com and the salvage yard both had it mislabeled as a 2008, VIN verification shows 13.) I read on “yourmechanic.com” that the “internals, most importantly the control module” is not compatible for someone asking the same question. I’m wondering if this is correct or if this is the answer given to those less mechanically inclined to entice them to click the “find a local mechanic” button.

Long story short, does anybody know if the 2008 and 2013 are truly incompatible or would it just need to be reflashed? My plan is to use the HP Tuner MPV12+ and VCM Editor to save my the flash off my 08 and reload it onto the 13, if that is even possible.

Any insight is greatly appreciated. Thanks.

the 6 speed was available for a while 6 speed was on the 2008 xFE model

 

[swathdiver]

Unfortunately, this is no longer listed on Amazon. Or even google. I would like to have a copy for my impending torque converter and front drum replacement.

There's nothing of consequence related to the torque converter. It deals mostly with the TECHM, valve body and pump improvements from Sonnax, things you've done already.

the 6 speed was available for a while 6 speed was on the 2008 xFE model

2009 was the first year for the SUV XFE. They were only made two years. The XFE was offered in the pickups until 2013.

 

[skpyle]

Thanks swathdiver, I appreciate it!!!

 

[Just Fishing]

I looked for that other book too, nothing found.

I used a combo of my FSM and the ATSG 6l80 shop manual to do mine.
Not much on the converter setback that talks about the 6l80 directly, but the set back depth is pretty standard among transmissions.
on my build thread:

Just Fishing's 09 Tahoe Build thread

Cold case radiator test fitting, Seemed to bind somewhere when installing, odd... Seemed like if I did some light trimming of the OEM standoffs at the bottom, it helped. I still need to look closer to see what's happening. but this is a very solid/tight fit... :think:

www.tahoeyukonforum.com

""
Converter setback spec, I converted to decimal for ease of my brain using feeler gauges and my caliper...
3/16 max = .187
1/8 min = .125

Setback measured = .143
I could tighten this a little, but it's pretty much perfect.
So, I'm running it.
""

I rebuilt my transmission and replaced the pump with a brand new unit.
Not fun since it seems you can't just buy a complete unit.
And there are selective pump rotors and slides... lol

Remaining tidbits found by spending hours watching and searching for videos on youtube.
Most confusing thing was setting the clutch clearances, so little information about the selective snap rings.

I even did a little snap ring mixing and matching to get the other clutch packs within spec.
Since I was replacing the 1-2-3-4/reverse drum proactively (plus I saw lots of wear where the steels ride), I had some leftovers.

Even the new factory "loaded" drum was on the looser end of the spec...
In the end I pretty much did my best to match those clearances to the rest of the transmission.

I found this manual that looks neat,

GM 6l80 Transmissions: How to Rebuild & Modify (Sa Design, SA523): Garrett, Steve: 9781613257302: Amazon.com: Books

GM 6l80 Transmissions: How to Rebuild & Modify (Sa Design, SA523) [Garrett, Steve] on Amazon.com. *FREE* shipping on qualifying offers. GM 6l80 Transmissions: How to Rebuild & Modify (Sa Design, SA523)

www.amazon.com

I did a google image search for that manual, and found a site that had some sample pages listed.
Not bad, and if I were to do it again I would probably pick it up.
(I saved it in a "wish list" just incase I get to do this again )

 

[Just Fishing]

Oh yeah, there are some pump improvements in the late 08 manufacture date of the 6l80.
My tahoe is 2009.

My transmission showed as being manufactured in late December of 2008, and it had the improvements.
there is also an improved style of clutch pistons that won't crack as easily as the older units.

I probably wouldn't think twice about going to a later unit.
Just understand the possible valve body differences.
And don't get rid of your old transmission until your 100% sure everything is working.

Worst case, you take your old techm and rebuild the pressure switches and reinstall it.
worser case, new techm and have it programmed by the dealer.