This weekend I had planned on changing all of my fluids in my truck. After having a truck that had damaged rear axle gears, I always drop my rear axle housing cover to examine and check for damage. I purchased a lot of the materials at GM but bought the rear axle cover gasket from Auto Zone only to find out that it is the wrong gasket. FelPro has the gasket listed as a RDS55063 and this is NOT correct. This is also the gasket listed on the Felpro home page, so the problem didn't come from Auto Zone but from Felpro. I will be calling Felpro on Monday to reveal that the part that they have listed is not correct and give them a little peace of my mind.

On another note, I noticed a lot of metal on my magnetic plug from the front axle housing. I was really surprised how much was on the magnetic plug and wondered if this was normal? Truck only has 24,000 miles on it.

Thanks

Craig

PS. They listed this gasket for all rear axles up to and including 2008. I'm sure that the LBZ and later has a different rear axle then LLY models and earlier. Sometimes it is best just to pay a few extra bucks and get it right from the dealer.

They are probably giving you a gasket for a 10.5" not an 11.5". Why not use silicone? BTW all 8.1's and 6.6's have the same axle 11.5"

ever one that has changed the front diff has had "excessive" junk on the magnet. seems to be the norm for the front diff. I did mine a couple weeks ago at 38,*** miles and had the same junk I've seen pics posted of here before. How'd you like the creamy color of the fluid in there too??

Moved to Drivetrain...

They are probably giving you a gasket for a 10.5" not an 11.5". Why not use silicone? BTW all 8.1's and 6.6's have the same axle 11.5"


Napa doesn't show a listing for 2007 and newer trucks saying that the bolt pattern is different. The Differential does use newer technology than the previous years and has been redesigned. Thought about using silicone but decided not to use it just in case I need to get back into the system again at a later date. Less mess to clean.

GM makes a rear differential gasket for the LBZ (Part # 12471447). I used one when I installed my PML diff cover and switched to Amsoil Severe Gear 75W-90 with 987 miles on the clock.

This weekend I had planned on changing all of my fluids in my truck. After having a truck that had damaged rear axle gears, I always drop my rear axle housing cover to examine and check for damage. I purchased a lot of the materials at GM but bought the rear axle cover gasket from Auto Zone only to find out that it is the wrong gasket. FelPro has the gasket listed as a RDS55063 and this is NOT correct. This is also the gasket listed on the Felpro home page, so the problem didn't come from Auto Zone but from Felpro. I will be calling Felpro on Monday to reveal that the part that they have listed is not correct and give them a little peace of my mind.

On another note, I noticed a lot of metal on my magnetic plug from the front axle housing. I was really surprised how much was on the magnetic plug and wondered if this was normal? Truck only has 24,000 miles on it.

Thanks

Craig

PS. They listed this gasket for all rear axles up to and including 2008. I'm sure that the LBZ and later has a different rear axle then LLY models and earlier. Sometimes it is best just to pay a few extra bucks and get it right from the dealer.

No they don't. The same AAM 11.5" 14 bolt axle has been used with the Dmax and 8.1 in 3/4 and up trucks since 2001. The cover has not changed.

If I were a betting man, I'd say you got the gasket for a Corporate 14 bolt 10.5" which is also used in the 2500 HD's behind the 6.0 gasser.