Do I need to replace my rear axle gaskets?

[Michael Kerich]

I have a 1999 Chevy Suburban 2500. I am doing some brake work on my suburban (replacing the springs, lubing the brake backing plate, checking the brake shoe thickness, and replacing the wheel cylinders because I broke the bleeder valves off of them). Problem is it has a full floater rear axle and I need to take out the axles out to get the brake drums off. I figure while I am at it why not replace the differential fluid. I am going to lose a good amount taking the axle out, it isn’t that expensive, I already bought all the gear oil to do it, and it makes sense probably hasn’t ever been replaced before. So, job consists of brake work and replacing differential fluid. In order to fully drain the differential fluid I have to take off the differential housing cover. Online I see a lot of people saying those aren’t reusable so I ordered a new one. Then, I realized that there is another gasket behind each of the axle flanges. And, it seems as if people are saying those aren’t reusable either. So, I came here to get some more expert advise. Here are my main questions…

#1 Do you guys think the differential housing cover gasket is…
A- Reusable forever
B- Reusable to a point (if so for how long can it be reused)
C- Not reusable, replace it every time

#2 Do you guys think the gasket that sits behind the axle flange is…
A- Reusable forever
B- Reusable to a point (if so for how long can it be reused)
C- Not reusable, replace it every time

I would say B for both, but I wouldn’t have any idea how long they would last and I am not a mechanic. I would say 18 years is too old to be reused (I am just assuming they are original). I don’t think I will ever need to take off my differential housing cover again and I already bought the gasket. So, why I am even bothering writing about it? Because, I want to see if I was wrong to have purchased it (btw it was $4.49). I have not purchased the axle flange gaskets yet. I plan to buy them tomorrow unless told otherwise. More questions…

#3 When putting on a new gasket do I just clean off both surfaces and slap the new gasket on there?

#4 When reusing a gasket do I just clean off the gasket, both surfaces it contacts with, and put the gasket back on?

#5 Do my torque specs look right for my vehicle?
Bolts for the axle flange – 115 ft lbs (that number seems wayyyy too low to me, I don’t know if I am looking at the right number)
Bolts for differential housing cover – 35 ft lbs (that number seems just a bit high, but it might be right)

P.S. I know what RTV is. They make gaskets for my suburban. I don’t like RTV. Most people use RTV because they can’t find the right gasket for their vehicle. My gaskets are easy to find and cheap so I will not be using RTV. I have heard some people say to use RTV with real gaskets and other people say not to. I don’t know which is right, but I think the safe route is to just use the real gasket.

Topic

[none]

Never reuse a gasket on the differential cover, It’s just a paper gasket and it’s going to break apart when you remove the cover anyway. You should be able to reuse the gaskets at the axle flanges if they’re metal seals. Reuse them all you want as long as they’re not heavily seeping or flat out leaking gear lube through them. Always clean all your mating surfaces where you’re going to use any gaskets. (Same goes for any reusable gaskets.) Make sure to cover up the differential any way you can while you’re cleaning up the gasket surfaces for the diff cover. Since you don’t like RTV, don’t use it. But do clean those gasket surfaces.

[Michael Kerich]

Makes sense. Metal gaskets can be reused, paper you can’t, got it. I was just about to order a bunch of those metal gaskets for the axle flange since I thought every time I took off the brake drums I needed to replace them. I was lookin a em last night thinking these really don’t look like they need to be replaced. You’re name is very ironic lol.

[none]

If you saw me try to get through a day in real life, you’d understand. 😀

If you can’t laugh, I can’t help you.

[Author]

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