front differental

[stevens cummins]

ok guys just found my front diff cover is leaking so im going to pull cover and re seal what do yall recommend using to seal it and what oil to put back in

[anoldbiker]

I know on my 06 I have a choice of paper gasket or silicone sealant. I believe it's the black sealant you can get from NAPA or AutoZone. Just make sure you torque properly and to specs. As for oil, I use Valvoline 75w-90 full synthetic oil. Also check you don't go over the proper oil level. I've read a bunch of guy in many forums have and they had seal problems. So I maintain level at the bottom of the axle tubes.

Edited July 17, 2014 by anoldbiker

[Mopar1973Man]

I typically use plain old silicone sealant and 85w-90 GL-5 gear lube (Petroleum).

 

I always over fill slightly I take my thumb and place over the hole and pump in about 2 more barrel pumps more of gear lube. This way and inspection time I unscrew the plug tip it a for a brief second take a sample on my finger and screw the plug back in. So the overfill thing is a total myth.

[Wild and Free]

What is the overfilling myth you are referring to?

 

I can say from my own experience 2 times one on my 02 and on my old 95 over the years that overfilling can lead to oil blowing out the breather on the front axles when hot in hot weather and making a heck of a mess.  I used to do the same thing you describe until that happened two separate times on two separate rigs, I now just fill level with bottom of fill hole and no more issues. I never had any issue with the rear diff but both times happened on the front.

 

As far as the rear diff, overfilling could cause things to run hotter than normal, it needs air space to sling and help cool the oil, take up the space and the oil has less space to sling and cool, probably a non issue in the small automotive diffs but it makes a huge difference on large equipment.

[mopartechnician]

Rtv unless they put a reusable gasket but most likely its rtv

[Mopar1973Man]

What is the overfilling myth you are referring to?

 

I can say from my own experience 2 times one on my 02 and on my old 95 over the years that overfilling can lead to oil blowing out the breather on the front axles when hot in hot weather and making a heck of a mess.  I used to do the same thing you describe until that happened two separate times on two separate rigs, I now just fill level with bottom of fill hole and no more issues. I never had any issue with the rear diff but both times happened on the front.

 

As far as the rear diff, overfilling could cause things to run hotter than normal, it needs air space to sling and help cool the oil, take up the space and the oil has less space to sling and cool, probably a non issue in the small automotive diffs but it makes a huge difference on large equipment.

 

Like I said place my thumb over the hole 2 more pumps. Throw the plug in. both the 1996 or the 2002 neither truck leak nor do then blow oil out. But I can tip the plug and it over fill slightly so I can get a sample and know its still full. With 2 trucks here and all 4 axles overfilled slightly no issues its got to be a myth about making axles or pinion seal leak with a few extra ounces.

[anoldbiker]

What I have read was on some aftermarket covers, they had the fill hole higher that the stock covers. When these guys filled, they had the oil level when at rest above the bottom of the axle tubes and always had oil contact on the outer seals. Then in time their seals leaked, they suggested saturation issues.

 

The first time I was dropping the stock cover, I pulled the plug and seen where the original level was at rest. Then, when the cover was off, ran a level to the bottom of the axle tube to see where it laid. It was at the bottom of the tube. I put the new cover on and filled to that level.

 

But as for fluids, the manual for my truck states full synthetic 75w - 90 gear old. 

 

Sorry for not responding earlier, seems when I subscribe to a thread and someone answers, I don't get an email to notify me. I need to check into this. I have @mopar1973man.com in my white papers, so it must be something else.