Aluminum Rear end cover?

[Yo Hoot]

I'll check it out.



So all the bolt holes on the GM rear line up and it doesn't need rtv.



All the bolt holes on the Dodge rear line up but it needs rtv?



What's up with that? Is the bottom fastener hole in a different loc on the Dodge?

 

[Chris N5CWM]

Take a closer look at this pic.



#ad




The O-ring is intentionally designed to go around the outside of the bottom bolt hole. The purpose of the RTV is to seal off the unused bottom hole, the threaded one in the axle housing. Otherwise fluid will just drain right out the bottom.

 

[Rosco]

Originally posted by Yo Hoot

I'll check it out.



What's up with that? Is the bottom fastener hole in a different loc on the Dodge?

I guess it's off just a tad. When I received the cover in the mail from Geno's they (Geno's) even added a notation stating it is necessary to fill the bottom hole for Dodge applications.

 

[Yo Hoot]

Maybe the caulk caused the leak

 

[Rosco]

Maybe.

 

[Chris N5CWM]

The RTV/Silicone/Caulk (don't use caulk! Use a Permatex type RTV that is impervious to oils) needs to cure for 12 hours at least, better yet 24. You can't just plug the hole and install the cover, and immediately fill the lube. Maybe that's what happened?

 

[TX Gooseneck]

I've never had any problems with RTV leaking.



I really feel like raising hell with DC about mine. My rear cover looks like it's 15 years old

 

[GerryDrake]

Chris. . is the picture you posted of the MH-AA11. 5 cover ?...



... or is the MH-AA11. 5 a new one to fit the American Axle 11. 5" diff's that doesn't have the need for RTV ?



Gerry

 

[Joseph Donnelly]

The Dodge version of the AAM looked the same as the GM that Mag Hytec already had a cover for. However, they later noticed that the housing was cast a little differently and the o-ring traveled too close to the inside edge of the sealing surface on the Dodge. Hence some early covers leaked. They have fixed that. The fact that Mag does not use the top or bottom bolt is not related. I always use RTV because the cover will not come off periodically. I use the drain plug to change lube. Maybe it is excessive to use RTV with the o-ring, but I don't get any leaks, either.