Rear axle bearing and seal replacement questions.

[Lil-j]

So my truck is in my garage again. I'm in the process of dropping the fuel tank for a pump replacement and fixing the leak on the top of the tank. Decided as long as the ass is in the air, might as well replace the right side axle bearing and seal while I'm at it.

I understand how to do most of the job and have the proper pulling and installer tools at the moment. My problem is that I cant figure out how to get to the C lock that holds the shaft in. And I did search here for how to's, found HenryJ's info on here but with out pics, this part is difficult.

I've got the diff cover off and fluid drained. I see the 8mm bolt that holds the pin in place.


I get that part, 8mm bolt comes out, slide the big pin out, rotate spiders out, C lock is behind, pull that out, slide shaft out, carry on.
BUT......


What is all the stuff in the way with the springs? I have no idea how to get that out........

I watched some videos on youtube of wheel bearing replacement but none show this part on the differ.
Any thoughts?

[Lil-j]

Also,



This is the 7.6 rear end right? It's a 10 bolt diff, as opposed to 12 bolt

[HenryJ]

That is the fly weight and engagement mechanism for the Eaton locking differential. Roll it over to the opposite side and you will see where you can retrieve the C clips.
There you go. That last picture is the right one. Push in on the axle and you will see the clip to remove. The center pin keeps the axles from coming in where they would fall out.

[Lil-j]

After looking at it again, second pic, it looks like I can get at the lock, but barely! Thank you for confirming that for me Henry!!! I'll let ya know how it goes, with pics!

For now, my truck in happier times

[HenryJ]

Make sure your new gasket has the holes for the axles to lube.

[Lil-j]

The diff cover gasket?

I can get a screw driver on the C lock, but cant figure out how to get the damn thing to come out of there. I cant he get the shaft in enough to let it slip off. And the lock is pretty thick so I dont think prying is going to work. Not sure what to do and dont want to take apart the locker. Or can I just take out the center pin to let the axle in more?

[HenryJ]

The center pin is the key that locks the axles outward and keeps the c clips on the axles.

Remove the lock pin. remove the center (spider) pin. Push inward on the axle. (With the carrier oriented where they can fall down) Sometimes a pick may be needed to rotate the clip allowing it to fall. I have a pair of hemostats that are thin enough to grip them for installation, but a magnet works too.

Once that is done, the real work begins. A pitted or worn axle shaft will require replacement. Pulling or prying the seal out is not bad. Pulling the wheel bearing can be "trying" to say the least. Many times I have resorted to cutting a relief with a torch to get them to pull out. A Dremel might work too? BE CAREFUL! Don't mess up the housing!

Luck be with you...

[Lil-j]

Ok, I though the spider pin had to come out. I dont want to have the spIders move though. I've got a magnet to get the clip out with. And I borrowed a puller set with a slide hammer to get the bearing and seal out from school. Plus the installer tool.

And thanks for the luck, I'm a gonna need it!

[HenryJ]

It takes some force rotate the spider gears. Move slow and make sure the tires move together. It will rotate just fine. Slow and easy rotation of the driveshaft.

When you put it back together make sure not to over torque and break the lock pin/bolt. I have seen them twisted off. Be sure to use a liquid locking compound on the threads. I have seen them fall out. That is messy. Lots of big broken parts. Expensive error.

[Lil-j]

Locktite?

The lock bolt is a PITA. Hard time getting it out.

[HenryJ]

Six point 5/16 or 8mm box end wrench. Give it (the wrench) a whack with a BFH and it will break loose.

[Lil-j]

Sucks, all my wrench's are 12 point.

Just got the tank down. I'm gonna have the pump out for warranty tommorrow. As well as fixin the leak around then top of the tank, I'll get pics of that.

[HenryJ]

Sucks, all my wrench's are 12 point.

Time to buy more tools! NAPA has them.

[Lil-j]

Rear end got finished last night. Once I got the lock bolt out, the rest fell apart and went back together easily. So thats done, onto the fuel tank.

This tank is rotting out on me so I'm gonna try to salvage it as best I can and see what happens. I'm taking pics as I go, I'll post em up later. Wish me luck fella's!

[HenryJ]

Sounding good. I think luck is with you.

[Lil-j]

One more question to bother you with. My little brother is aruing with me that my rear diff needs 80/90w gear oil w/friction modifier for limited slip, I say no. Who is right? Manual says no friction modifier. Looking at the above pics, whats the correct answer?

[HenryJ]

You have the G80 Eaton GovLoc differential. Use only 80/90W GL-4 lubricant. NO FRICTION MODIFIERS / LIMITED SLIP ADDITIVE.

[Lil-j]

Crap! Talked to my brother again, he did a diff oil change for me a few months ago as I didnt have the time to do it.......He used the oil with LSD additive. I'll be changing the oil out tommorrow. Hope there wont be any problems..........



Guess thats what I get for being in a hurry!!!!!!!!

[killian96ss]

Save your money, you don't need to change your diff oil. Almost all GL4 and GL5 gear oils contain some friction modifier. If you had a limited slip that used spring loaded clutch packs or a spring loaded cone you would need to add additional friction modifier to prevent chattering, but since you have a Gov Lock you don't want or need to add modifier. The Gov Lock does have clutches, but they work differently than a limited slip.

Steve

[HenryJ]

Crap! Talked to my brother again, he did a diff oil change for me a few months ago as I didnt have the time to do it.......He used the oil with LSD additive. I'll be changing the oil out tommorrow.

No more than a couple quarts of lube costs, I'd dump it for good measure.
Cheap peace of mind.

[Horsehammerr]

Make sure your new gasket has the holes for the axles to lube.

Pulled my cover, and yes it had pucky water contaminated oil. The cover had no gasket , only hi heat silicone sealer. Never any problem with oiling. What do you think ?

[HenryJ]

Relocate the vent tube, Personally for no more than the cost of the slotted gasket, I'd buy one. In a pinch RTV will work fine. You do risk the reduced wheel and carrier bearing lubrication though. You won't know if that was bad until they fail. The flexy little 7.625 rear axle has enough problems. I'd want every advantage. That said, I gave mine every advantage and it still failed. The 8.5" was my answer.

[Horsehammerr]

Is there a list of the required amounts of lube in the different locations on our trucks and if synthetic oil should be used in the differentials ? I am moving the vent hose to a high and dry location, somewhere in the area of the fuel tank vent I think.

[Lil-j]

The rear diff is easy, just fill till it starts coming back out, done.

[HenryJ]

Is there a list of the required amounts of lube in the different locations on our trucks ...

Look at the stickies for this section.

Lubing and Manuals

GM Fluid Capacities and Lubricant Recommendations

Also in your owners manual (paper or electronic)

Also in our stock information page there are capacities Detailed Specifications.

[Horsehammerr]

Thanks Brule ! It's just that I hate it when I have to stop everything , clean up and drive back to the shop to get more oil, 'cause I didn't check how much was needed to begin with. You don't happen to have a PN for the right cover gasket for our differential do you ?

[HenryJ]

I do not. Finding the right one with oiling holes is the key. Might check that thread and see if it lists part numbers?

[Horsehammerr]

I do not. Finding the right one with oiling holes is the key. Might check that thread and see if it lists part numbers?

I can not see any oiling available with a flat surface cover plate. What advantage would extra holes in the gasket serve ? The only cover gasket I can find with a slot , is in the 8.6 cover plate gasket. There are two holes in the cover surface, one on each side in line with the axles , but nothing on the cover at these points. What am I missing ?

[HenryJ]

Wrong Differential Gasket And Cover ?

» 14 Nov 2003 09:04 am
I'm not sure if this has been discussed before, but I'll mention it anyway. GM has been installing the wrong differential cover gasket on all 10 bolt rear ends for at least 10 years now. I just put on a new Summit aluminum rear end cover with bearing cap preload bolts last night and noticed that the factory gasket and even the factory cover are completely blocking the side oiling holes for the wheel bearings! I found this same problem on my 10 bolt equiped 96 Impala SS. I know most of the people in the Impala / Caprice community have known of this problem ever since they started making them. I just recently read a thread on the Impala SS forum that states all 10 bolt rear ends both cars and trucks have this incorrect gasket. Basically your wheel bearings will fail much sooner than they should because of the inadequate oiling. Even the gasket I got with the Summit cover had the holes blocked, so I put the gasket on the rear end and marked the holes and cut them out. I even filed my own oiling holes into the aluminum cover to be sure my bearings are getting oil. So, the next time anyone here is changing their rear end fluid or putting on an aftermarket cover take a look at the oiling holes and you'll see what I mean. BTW, GM does not admit to the problem, so you probably won't be able to have then cover it under warranty, even though the problem is very obvious. Hope this info helps, Steve K.

http://www.socalss.org/special/holes.htm

You don't file gaskets. You cut them. If you use the correct gasket with the hole open , there are no modifications needed to the gasket.
The covers no longer have provisions for oiling. That is what needs to be modified...

Maybe little or no help on a stock cover. Can't hurt though and our stock 7.625" diff needs all the help it can get. Best advantage is for those that see lots of highway use.

[Horsehammerr]

So basically , with the stock cover , the slotted gasket is useless. I mean since there are no oiling passages in the stock covers, who needs oiling slots, right. Unless you just gotta have a snazy aluminum cover with free advertizing for summit on it, that you can hopefully grind your own oiling slots in, in the right place. Seems to me the best mod is to eliminate the free GM water bath cooling vent hose location.

[killian96ss]

The aluminum cover is more than just "free" advertising. The extra thick aluminum combined with bearing cap preload bolts helps prevent the case from flexing which is common on the 7.625, it offers superior protection compared to the weak stamped cover, it has drain and fill plugs with magnets to remove metal, and the oiling channels can be filed into the cover to help prevent premature bearing wear and failure.

Steve

[HenryJ]

So basically , with the stock cover , the slotted gasket is useless. I mean since there are no oiling passages in the stock covers, who needs oiling slots, right. ..

Wrong. The stock cover does not completely cover the oiling hole and using a gasket adds some clearance. The gasket will cover the hole if it is not open, but if it has a hole or slot it will direct some oil to the axle tube.
Is an aluminum cover better? Yes.

[Horsehammerr]

Well , what I did was RTV around all the bolt holes and in between , then just around the outside of the axle oil holes. That is how the cover was in place when I removed it. By the appearance of the differential this had never been touched from the factory. Has anyone else pulled their cover and found no gasket ? Just a complete coating of sealer. After 160,000 miles the only wear I have found is brakes , tires, and parking brake. The gears looked very good with very little polishing on the contact surfaces and I know my posi. works when it's supposed to.