Main Bearing Gasket Replacement

[alvocado]

The main bearing gasket between the transmission housing and engine is leaking oil on my 2002 Yukon Denali. The leak is worsening so I will likely have to replace the gasket (u-shaped gasket in the pic.)

 

I'm comfortable taking this on but want to confirm if the main bearing seal replacement procedure is well documented in the GM shop manual, assuming I follow the same procedure and to the bearing seal as well. I'll plan to purchase the full manual prior to making the repair. I understand it's also recommended to replace the oil pan gasket at the same time since it can be compromised when the transmission housing is removed.

 

Any input from a GM tech on the level of detail in the GM manual for the replacement is appreciated. Specifically, is this a job with a lot of undocumented steps or is it pretty straight forward? Thanks.

[alvocado]

Anyone with a factory manual out there?

[gmtech4]

online only and very expensive

[alvocado]

online only and very expensive

 

So GM no longer sells factory manuals (DVD or printed) through the parts department? I can get a yearly subscription to Alldatadiy for $26.95/yr for a single vehicle.

[Bronc]

Helm Factory Manuals

[alvocado]

Helm Factory Manuals

 

Thanks for the link.

[bcb1]

The main bearing gasket between the transmission housing and engine is leaking oil on my 2002 Yukon Denali. The leak is worsening so I will likely have to replace the gasket (u-shaped gasket in the pic.)

 

I'm comfortable taking this on but want to confirm if the main bearing seal replacement procedure is well documented in the GM shop manual, assuming I follow the same procedure and to the bearing seal as well. I'll plan to purchase the full manual prior to making the repair. I understand it's also recommended to replace the oil pan gasket at the same time since it can be compromised when the transmission housing is removed.

 

Any input from a GM tech on the level of detail in the GM manual for the replacement is appreciated. Specifically, is this a job with a lot of undocumented steps or is it pretty straight forward? Thanks.

 

 

Definitely need the Kent Moore alignment tool to install the rear main seal on a 5.3 engine. When I had my mechanic replace my tranny, I thought heck, since it's out we might as well replace the rear main seal as well. Uh, bad idea. He didn't have the alignment tool, and it made the leak a lot worse. He finally ended up borrowing the tool from a tech at the Chevy dealership and got a new seal installed.

 

But after all that, I still had an oil leak! It was the oil pan gasket leaking all along, not the rear main seal. So you might want to do the oil pan gasket first and see if that fixes your leak. It's much less labor intensive than the rear main seal.

[ChevyTech77]

Lots of special procedures to these engines when it comes to oil pan, rear main seal carrier and seal alignment repairs. I wouldn't attempt them without the special tools. The service information from GM is pretty much on

the money as far as accuracy.

[alvocado]

I used oil dye and confirmed it's the housing gasket. Main seal and oil pan gasket replacement would be done as preventative maintenance while everything is removed. I have the 6.0L Denali so is a main seal alignment tool or other special tools required?

[ChevyTech77]

I used oil dye and confirmed it's the housing gasket. Main seal and oil pan gasket replacement would be done as preventative maintenance while everything is removed. I have the 6.0L Denali so is a main seal alignment tool or other special tools required?

 

Yes, they are. If done without, it will leak worse.

[whitedenali]

I used oil dye and confirmed it's the housing gasket. Main seal and oil pan gasket replacement would be done as preventative maintenance while everything is removed. I have the 6.0L Denali so is a main seal alignment tool or other special tools required?

 

 

Got the same issue. And I know this was posted in 2010 but how did the fix go?