2nd Gen Non-Engine/Transmission Differential Cover Sealer

[rspeers]

I changed the lube in my diff last month with AMSOIL 75-140. I used the sealer recommended by the local auto store. It is leaking now. Can anybody tell what to use without buying from DC.

 

[Wiredawg]

Use high-temp silicone

Remove the diff cover. Completely wipe down mating surfaces of diff and diff cover and clean with brake or parts cleaner. Run a 1/4 inch bead of black high-temp silicone sealer on you diff cover. Be sure to circle the bolt holes. Let set for about 30 minutes. Put cover on with bolts only finger tight. Let set for another 30 minutes. Then, begin to tighten in cross pattern. Don't have my manual handy, but seems like it's 14 ft lbs. Double check the torque rating.



Should be leak free!



Wiredawg

 

[BillGotthelf]

You don't have to use Hi-temp. Rear end temps very rarely go over 175. Any good quality RTV silicon sealer will work otherwise Wiredawg hit the nail on the head.

 

[Wiredawg]

Billgothelf is right. I've just gotten in the habit of using high-temp on any component that generate any heat. Overkill-yes maybe, but I stand by my record of zero leaks on oil pans, valve covers and diffs. A tube will last you for a really long time.



So, you could save the $. 75 or...



Wiredawg

 

[BillGotthelf]

Wiredawg-lasts a long time (one tube)? If I open a tube-3 months later when I go to use it it is solid as a rock-I always buy 3 tubes.

 

[illflem]

I use Perma-Tex flange sealer, sort of expensive but the same tube has lasted 4 years on two trucks and numerous other applications without a drip.

Whatever you use don't use too much. Any excess squeezed inside the differential will eventually find it's way to a bearing or seal possibly causing damage.

 

[HiPerf360]

The AmsOil is causing the problem... LOL



Just kidding, The other uys gave you good advice.

 

[Royal]

Get a Mag-Hytec cover and you won't need a sealer.

 

[John Berger]

Royal, that's true most times

... but not always. On my first axle housing, the Mag-Hytec mated perfectly. When it was replaced under warranty, I could never get the Mag-Hytec to mate to the new housing without leaking. I finally went to RTV. When it dried and I knew I was leak free, I trimmed all around the edges and now you can't tell that there was any RTV used.

 

[Rman]

Axles can be a real pain. One thing i always do is let it cure over night before adding any oil. I've done it a couple times without and it still didn't leak, however i've never had it leak when i let it cure for a day.



On my 4x4 beast i change the axle fluid monthly because of the possibilty of water contamination... i obviously use the cheapo valvoline brand (140 bucks a case for amsoil once a month wouldn't be prudent). So getting my axles to seal has become kind of a science! Since i change so often you'd think i'd wise up and buy a cover with a plug... hell no i'm cheap and set in my ways. The mag hytecs are just to big and bulky for crawlin over rocks, can get kind of scary at times.

 

[BillGotthelf]

John I had the same problem with my mag-hitec on my 96. Without using sealer it leaked no matter how clean it was. RTV stopped the leak for the last 3 years.

 

[Matt42]

Any decent quality RTV sealer should work fine. I used Permatex gray oil resistant. Something to keep in mind is that RTV silicone will not adhere to petroleum distillates. Most people think of oil or diesel when they think of petroleum distillates. A lot of people use lacquer thinner to clean mating surfaces before they re-seal them. Unfortunately, when it comes to RTV silicone, lacquer thinner behaves like 00 weight oil. (So do some chemical gasket removers. )



I use denatured alcohol as a final wipe. I use it liberally, then wipe it down with a fresh paper towel. Once I started doing that, I NEVER had another oil leak. Not even a drip. I even used that technique when re-sealing an AMC-Jeep 258 six cylinder engine's plastic valve cover. (You Jeep guys know about THAT!) The valve cover quit leaking. Everything else kept leaking, but the valve cover didn't.



Brake cleaner should also work.

 

[DragsterRob]

I prefer Loctite Anaerobic Gasket eliminator. I ran into it working on heavy equipment. It does not peel off on the inside of what ever you are sealing like silicone. This can be a real problem on hydraulic systems. For that reason, I just hate messy silicone. I use formula 515. I have seen it a some auto parts stores, but I know the Case dealership has it. It is expensive, but it works. I also use the loctite primer "N" to prep the surface. Just my 2 pennies worth.

 

[rubberneck]

I use a product called the "right stuff" it is killer stuff. comes in a can similar to "squeeze cheese". They are proud of the stuff, but it works great, it is the only stuff that i have found to seal fast coolers the first time everytime. I wish they had an oring like the maghytec

 

[Badunit]

Some people let the RTV cure and get a skin on it before mating the parts together. The tube (at least the ones I've seen) and the service manual say to mate the parts within minutes. I've always mated the parts and tightened everything up within minutes and never had a problem. I figure this way it bonds to both the cover and the differential housing for a better leak-tight seal.



One more important point with RTV: Don't overtorque the bolts, it just squeezes out the sealer and reduces the quality of the seal.