'07 Yukon XL Transmission Rebuild ??

[BSarteSr]

My '07 Yukon XL Denali has ~165k miles on it.

The rear seal on the motor has been leaking for awhile, I keep cardboard under where it leaks in the garage. The cost is ~$1200 to replace the seal.

Not sure what trans is in it, might be a 6L80? Works fine.

I know if I decided to have the rear seal leak fixed, no sooner will it be done then the trans will need to be rebuilt. So I want to wait to do the rear seal when the trans needs to be done. Why pay to have the trans taken out twice!

I drive the Yukon easy (not accelerating quick, no towing) like an old man (I am 68 years old, retired, and drive like it!).

What is the longevity for the trans?

I had a '95 Suburban before this Yukon and it was Karma that about every 75k miles the trans would go and needed to be rebuilt, so after 340k miles it had been rebuilt 3 times. That was a 4L60E trans and I towed a car trailer with it occasionally.

 

[Geotrash]

My '07 Yukon XL Denali has ~165k miles on it.

The rear seal on the motor has been leaking for awhile, I keep cardboard under where it leaks in the garage. The cost is ~$1200 to replace the seal.

Not sure what trans is in it, might be a 6L80? Works fine.

I know if I decided to have the rear seal leak fixed, no sooner will it be done then the trans will need to be rebuilt. So I want to wait to do the rear seal when the trans needs to be done. Why pay to have the trans taken out twice!

I drive the Yukon easy (not accelerating quick, no towing) like an old man (I am 68 years old, retired, and drive like it!).

What is the longevity for the trans?

I had a '95 Suburban before this Yukon and it was Karma that about every 75k miles the trans would go and needed to be rebuilt, so after 340k miles it had been rebuilt 3 times. That was a 4L60E trans and I towed a car trailer with it occasionally.

Yes, yours is a 6L80E. I have 220K on the original in my 2007 XL Denali and do a fair amount of towing with it as well. The weak link in the 6L80 is the torque converter. GM's factory programming engages the lockup clutch in at least gears 3-6 (and some sources say 2nd as well), and also allows a lot of slip in the engagement of the clutch for smoothness. Unfortunately the cost of that is that the lockup clutch starts to eat itself in about your mileage range, and when it fails, it sends metal through the transmission and cooler lines, taking the whole system out in the process. Another weak link is in the valve body, which many here have repaired on their workbenches. The transmission itself is pretty stout and will last a long time. It's the TC and valve body issues that seem to lead to their demise.

If I were in your shoes right now with a leaky rear main seal, I would take it to a transmission shop and have them replace the rear main and rear cover seals, and install a new, upgraded torque converter with a billet cover and stronger lockup clutch. My shop installed a CVC BU60FHD in mine because they've had good results with them and it's been great so far. CVC is a nationwide rebuilder and they've engineered their own upgrades to the factory converter designed to make it stronger and last longer. When I had my 2012 done last year, it ran $1400 out the door for the same job.

And if at some point you start having trouble with shifting and flaring, you could have them tackle the valve body for only a few hundred $, or do it yourself. A complete rebuild will run about $3500 installed and they can reuse the CVC converter.

You may also want to take a look and make sure that it's really the rear main seal that's leaking. There is an oil cooler block off plate just above the oil filter with a gasket and an o-ring that are notorious for leaks on these, and it often masquerades as a rear main seal leak. You can pull the little metal cover at the bottom of the bell housing to look inside and see if there is a lot of oil in there. If not, you know the leak is coming from elsewhere.

 

[BSarteSr]

Yes, yours is a 6L80E. I have 220K on the original in my 2007 XL Denali and do a fair amount of towing with it as well. The weak link in the 6L80 is the torque converter. GM's factory programming engages the lockup clutch in at least gears 3-6 (and some sources say 2nd as well), and also allows a lot of slip in the engagement of the clutch for smoothness. Unfortunately the cost of that is that the lockup clutch starts to eat itself in about your mileage range, and when it fails, it sends metal through the transmission and cooler lines, taking the whole system out in the process. Another weak link is in the valve body, which many here have repaired on their workbenches. The transmission itself is pretty stout and will last a long time. It's the TC and valve body issues that seem to lead to their demise.

If I were in your shoes right now with a leaky rear main seal, I would take it to a transmission shop and have them replace the rear main and rear cover seals, and install a new, upgraded torque converter with a billet cover and stronger lockup clutch. My shop installed a CVC BU60FHD in mine because they've had good results with them and it's been great so far. CVC is a nationwide rebuilder and they've engineered their own upgrades to the factory converter designed to make it stronger and last longer. When I had my 2012 done, it ran $1400 out the door for the same job.

And if at some point you start having trouble with shifting and flaring, you could have them tackle the valve body for only a few hundred $, or do it yourself. A complete rebuild will run about $3500 installed and they can reuse the CVC converter.

You may also want to take a look and make sure that it's really the rear main seal that's leaking. There is an oil cooler block off plate just above the oil filter with a gasket and an o-ring that are notorious for leaks on these, and it often masquerades as a rear main seal leak. You can pull the little metal cover at the bottom of the bell housing to look inside and see if there is a lot of oil in there. If not, you know the leak is coming from elsewhere.

Thanks, exactly the info I was looking for!

 

[Foggy]

Do exactly what Geotrash says !!!!!

 

[donjetman]

Thanks, exactly the info I was looking for!

I did the rear main seal myself 3+ yrs and 41k miles ago. My 6.2 and 6L80 have 173k miles today and all is well. I drive mine like you drive yours. When I had the tranny out I changed some seals on it and installed another torque converter. Here's a thread I did w/pics: https://www.tahoeyukonforum.com/threads/rear-main-seal-job-pan-etc-07-yukon-denali-6-2.108334/

 

[BSarteSr]

Yes, yours is a 6L80E. I have 220K on the original in my 2007 XL Denali and do a fair amount of towing with it as well. The weak link in the 6L80 is the torque converter. GM's factory programming engages the lockup clutch in at least gears 3-6 (and some sources say 2nd as well), and also allows a lot of slip in the engagement of the clutch for smoothness. Unfortunately the cost of that is that the lockup clutch starts to eat itself in about your mileage range, and when it fails, it sends metal through the transmission and cooler lines, taking the whole system out in the process. Another weak link is in the valve body, which many here have repaired on their workbenches. The transmission itself is pretty stout and will last a long time. It's the TC and valve body issues that seem to lead to their demise.

If I were in your shoes right now with a leaky rear main seal, I would take it to a transmission shop and have them replace the rear main and rear cover seals, and install a new, upgraded torque converter with a billet cover and stronger lockup clutch. My shop installed a CVC BU60FHD in mine because they've had good results with them and it's been great so far. CVC is a nationwide rebuilder and they've engineered their own upgrades to the factory converter designed to make it stronger and last longer. When I had my 2012 done last year, it ran $1400 out the door for the same job.

And if at some point you start having trouble with shifting and flaring, you could have them tackle the valve body for only a few hundred $, or do it yourself. A complete rebuild will run about $3500 installed and they can reuse the CVC converter.

You may also want to take a look and make sure that it's really the rear main seal that's leaking. There is an oil cooler block off plate just above the oil filter with a gasket and an o-ring that are notorious for leaks on these, and it often masquerades as a rear main seal leak. You can pull the little metal cover at the bottom of the bell housing to look inside and see if there is a lot of oil in there. If not, you know the leak is coming from elsewhere.

I changed the oil today. While I was under there I looked at what you said about the oil cooler block off. First I took the metal cover on the bottom of the bell housing part of the transmission. Looked very clean in there. Cleaned all the oil around that area and put the cover back on.

I could see where you were talking about, saw the cover with two 10MM head bolts holding it in place. Took a wrench and each of the bolts were a bit loose so I tightened then maybe 1/8 to 1/4 turn. Also cleaned all the oil residue around all of the bottom areas so if it leaks again I hope I get a better idea of where exactly it is coming from.

Thanks for the info! I sure hope this fixes the oil leak problem!

 

[BSarteSr]

Geotrash, do you know what the GM part number for the oil cooler cover seal is? Having a little bit of trouble finding the exact one.

 

[Geotrash]

Geotrash, do you know what the GM part number for the oil cooler cover seal is? Having a little bit of trouble finding the exact one.

Here you go!

GM Genuine Parts 15203889 Engine Oil Cooler Gasket https://www.amazon.com/dp/B0987T9PRB/ref=cm_sw_r_cp_api_i_CY0R4DQXDAD3ZBZY4TN9?_encoding=UTF8&psc=1

 

[BSarteSr]

Here you go!

GM Genuine Parts 15203889 Engine Oil Cooler Gasket https://www.amazon.com/dp/B0987T9PRB/ref=cm_sw_r_cp_api_i_CY0R4DQXDAD3ZBZY4TN9?_encoding=UTF8&psc=1

Thanks! Very much appreciated.

 

[me88]

Here's some more info about this possible leak: https://testing-public.carmd.com/Tsb/Download/115431/2713908