Replacing Rear Axle Seals

[Indycars]

I'm replacing the seals for the rear axles. Now it's been 35 years since I had one apart, so memory is alittle foggy. Also there is more than just 4 spider gears inside the carrier, so this part I've never seen before.

To take the axles out, I need to remove the 3/4" pin and push the axles in about 1/2" and remove the C-Clip.

What should I be aware of after I removed the 8mm bolt and the 3/4" pin. Anything going to fall out on the ground. Which side do I remove the C-Clips from???

 

[grumpyvette]

gtr1999 happens to be both a member on the site and an expert with experience in this area, I sent him an EMAIL/PM hopefully he will reply


BTW I don,t do 10 bolts if I can avoid it, I just sheared and SHREDDED too many in the 1970s
and even the dana 36 and 44 that came in corvettes suck, in durability in my opinion when you throw serious torque and shock loads at them
(HINT HINT HINT!)

viewtopic.php?f=71&t=5083

viewtopic.php?f=71&t=1282

 

[Indycars]

The shop wanted about $450 to replace both seals. Maybe this is one of those learning experiences you refer to as "Getting in Over Your Head". Luckily it's an extra vehicle in my stable at this time, trying to sell a 1985 Chevy Caprice that I bought when it had 34,000 miles. It's got about 150,000 miles now.

Thanks for sending a PM to gtr1999. Tomorrow I will have to forge ahead into the great unknown, with or without extra info.

 

[gtr1999]

Hi
Although I usually stick with the Eaton posi's this is what I call the ratching posi from GM. They work like an open diff until a wheel slips and then it locks up. I wouldn't recommend using it for a HP application, I've had one fail in my '85 S10 with under 100hp.

I'm not sure what type of diff that is off hand but I'm pretty sure you can get a new Eaton to fit it and even a new loaded Eaton is better then those in performance cars. I usually don't use the new loaded Eatons either because I don't like the internals so if you really want a better unit it's best to build one using 10-17 spiders for your axle count,solid steel clutches,and polish and tune it. In basic form like that it should hold up great. How much depends on the rest of the build but this is how I build the vette diff's from 63-79 and those range from 400-1000hp ratings. The 600Hp + is based on a 12 bolt not a 10 bolt setup.

If you plan on using this one just check with a GM overhaul manual, it should cover it and there is probably something on you -Tube as well.

If you plan on removing the case then be sure to stamp the caps,L&R. If you just want to replace axle seals, then remove the c-clips and slide out the axles and you can get to them. All you need to do in the diff is install a new gasket,posi additive and gear oil.

The pinion seal is more involved and I have a thread on replacing those in a vette which is pretty much the same.
Here it is

http://www.digitalcorvettes.com/forums/ ... hp?t=76719

 

[Indycars]

I should have mentioned that it's a 1993 GMC Suburban and I'm just replacing seals and not wanting to build it for HP. It's just a family vehicle.

When I pull the 3/4" pin, anything that I should be ready for? Which side of the carrier will I pull the C-Clips from?

Thanks for the help!

 

[grumpyvette]

HERES THAT POST GTR1999 POSTED
This is a 1971 LT1 Diff a local guy brought in to me to check for him last winter.

This car was just purchased and he was told no one worked on the diff to their knowledge. I checked the side yoke play. .020-.025" was found but the play was in the sloppy stock posi not yoke wear. This will be discussed in another post or two so you'll just have to wait!:smack What I did was to mount the diff on my engine stand and put some gear oil it. After 5-6 hours I noticed a leak at the pinion seal and proceeded to replace it.


Here is the diff sitting on the stand with oil in it. I do this with every rebuild as well just to be sure. I let them sit 24-48 hours sometimes more.

Here is the close up.

Before tearing it apart you want to know where the reference points are. If doing this in the car you need to mark the pinion yoke,nut, and pinion end so that they all go back together in the same relationship to maintain the bearing preload. Since I have it out it is much easier to get a precise reading of drag with my 0-30 in/lb dial wrench. Used bearings should spin smooth and have about 5 in/lbs of drag.

I found someone was into this before. The witness marks were there and I heard the replacement seal hitting the yoke shield when I turned it by hand.

I use a puller to remove the yoke, this is one my friend Tom Buddy clued me in on years ago. Works great on these and rebuilding a diff when you have to pull the pinion off a lot during setup.

You want to look over the parts when you remove them. Here is the seal the previous mechanic installed.You have to look at the gap between the flange and housing. Usually it's about .125" but that can vary. Hitting it home will distort it and leaving too high the yoke will hit the flange as on this one.

You can see where the seal flange hit the yoke.

Also the last guy was clueless installing the seal. Here are the pinion yoke splines- no sealer. Oil will wick up and out if installed like this.

Here is the yoke. Look at the OD where it mates with the seal. If there is wear there you need to buy those expensive speedy sleeves or you'll have a leak.

Unlike some places my goal is not to sell parts or services. Instead of telling the guy the yoke was NG I cleaned it up and checked it on our scope. This one didn't need the sleeve.

Here's the new CR seal. Spend the extra couple of bucks and buy the best parts. Not all seals are the same and I have seen some rebuild kits on the market with the cheapest junk you can find. This is a CR/SKF seal.

Here is the secret to stopping a future leak- good old #2 on the splines. A few bucks for the right stuff saves you a lot of swearing in a few weeks!:spanked:

Back together, torqued and ready for the leak test.

24 hours later dry as the moment I installed it.

I reused the yokes with 90k miles on them, replaced the seal, installed Lucas 85-140 gear oil and GM additive, Back to the owner.

This is the type of post I usually do. What is your feedback?

Gary

 

[northrnyankee]

if you are just wanting to change the axle seals just remove the lock pin and then the pinion shaft. Nothing will fall out and once you get the pinion shaft out just smack the axles in and the c-clips will fall out allowing you to remove the axles. When you're removing the pinion shaft I rotate the carrier and push the pinion shaft out about an inch, don't push the shaft too far or you won't be able to turn the carrier, then rotate the carrier 180 again and the lock pin or small screw driver can be used to help remove the shaft. When your turning the carrier the c-clips will fall out if they havn't already. I assume you already know if the axles seals are leaking then there is a good chance the bearings have worn a groove on the axle. If there is a groove in the axles and you don't want to replace them there are axle saving bearings you can buy that use a different area of the axle.

 

[gtr1999]

I agree with Nothern Yankee , all you need to do is have a magnet ready, remove the cross shaft bolt,use the magnet to pull out the shaft, slowly push the axle in and use the magnet to pick up the c-clip. Then the axle can be pulled out from the diff and you can check the parts.
Good luck
Gary

 

[Indycars]

Many thanks guys, that's the kind of info I was hoping to get !!!

 

[Indycars]

The 93 Suburban has 142,000 miles on the vehicle.

The bearing and seal surfaces look good to me, I can't feel any grooves. Anybody think differently ???

 

[northrnyankee]

those axles look ok to be cleaned up and reinstalled. How bad were the seals leaking and what do the bearings look like?

 

[Indycars]

those axles look ok to be cleaned up and reinstalled. How bad were the seals leaking and what do the bearings look like?

I'm glad you agree, the seals are already in and diff cover installed. I cleaned the bearing surfaces with scotch brite and inspected again, all looks good.

The brakes and inside the drums were saturated in oil, I'm replacing the brake shoes with some Wagner shoes. I rolled the bearings and looking and feeling each roller, didn't find any rollers that had any roughness, visually or by feel.

Thanks for the help!

 

[northrnyankee]

I would think that if both sides were leaking the seals themselves were the problems since the axles look good. Glad we could help, I've built a few rear ends after learning it from a pro so it's nice to pass along some tips.

 

[Indycars]

Just a couple more photos to show how the C-Clip comes out for others that read this thread. I was concerned with pinion shaft out, that a spider gear/pinion gear would shift making it hard to put the shaft back in, but nothing moved, even when I rotated the carrier. The pinion shaft started sliding out of it's own weight, once I removed the 8 mm locking pin bolt.


This is before I removed the pinion shaft (3/4" shaft), you can barely see the C-Clip trapped in the spider gear recess.


Here you can see where I have the C-Clip started in on the left side only.

 

[northrnyankee]

all the components in every posi are installed before the pinion shaft goes in so none of the posi components will move when the pinion shaft is removed. The only things that can move which are not related to the posi components is the thrust washers for the two pinion gears but if they do that means they are worn and need to be replaced. The pinion gears can also move but you'd need to rotate the side gears in order for that to happen. With the axles out you don't have to worry about the side gears moving if you rotate the carrier