rear axle bearing question

[tonyfromjersey]

I'm in the process of doing the rear axle bearings on my 77, which apparently has the rear end off a 78 or later. Anyway, got the new bearings pressed on the axles and I'm almost ready to go.

Here's my question: I also bought new oil seals. How do I remove the old ones from the housing?

This project probably cost me the last decent weekend of the driving season, although I've been known to drive in the cold anyway, as long as there's no snow.

[mdrburchette]

Hope you get an answer, Tony. One thing I haven't had to do to mine is anything on the rear of the car. Lucky me!

[tonyfromjersey]

Got one from Ralph, I'll try it tomorrow. He said to hit it with a screwdriver and bend it then it will come out. I'll take a shot at it.

[Curly]

I use a slide hammer fitted with a small hook on the end. The hook goes inside the lip of the seal and pulls the seal out when the slide hammer is used. Be careful prying it out with a screw driver, you don't want to score the face that the seal mounts onto as it will cause a leak - don't ask me how I know

[ventura ace]

Curly,
How did you ultimately fix the leak? I've been battling a rear axle seal leak for several years, and can't figure out why it's leaking. No scratches where the seal sits. I use silicone RTV to assist the seal on the outside when pressing in place. The axle sealing surface is smooth, no scratches. The seal seems to be tight around the axle. I've replace the seal several times now and can't get the leak to stop. It's been suggested to shorten the energizing spring inside the seal -- I am probably going to try that for the next attempt. Any other ideas?

Alvon

[Curly]

G'day Alvon, I feel your frustration I've had a similar issue with the coupe that was finally fixed a couple of yeas ago when I attacked the seal mounting surface inside the axle housing with some 400 grit wet & dry paper. It removed all the fine scratches that had been inflicted over the last 40 years and left a smooth surface for the seal to to fit into. I also used an aircraft quality 'stud sealer' when fitting the new seal to the housing.
I've also managed to fix a different leak that was caused by a scored surface on the axle (where the lip of the seal runs) by using a stainless steel 'Speedy Sleeve' that is pressed over the axle up to where the seal runs. They are about half an inch long and are available in a range of sizes - one of which is a snug fit over the axle. Fitting a Speedy Sleeve also has the effect of increasing the tension of the seal on the axle due to its slightly larger diameter. I've also thought about shortening the spring behind the lip, but never had any success cutting and rejoining the spring
Keep at it mate, I'm sure you'll eventually get it beaten.

EDIT: One other thing I just thought of that I''m sure you probably also considered is the rear axle breather. If it's blocked, pressure can build up in the axle housing and force the oil out past the seals. It can simply be unscrewed and cleaned out if blocked.

[seabeelt]

Curly, I dont think I have seen that. Can you describe where the breather is located. Many Thanks

[azygoustoyou]

Got a pic of it Curly?

[Curly]

I'm not surprised you can't find it it's a litlle 'pimple' thingy up on the top of the diff banjo casing and probably covered in decades of grease and grime like the one in this pic.

[ventura ace]

. . .EDIT: One other thing I just thought of that I''m sure you probably also considered is the rear axle breather. If it's blocked, pressure can build up in the axle housing and force the oil out past the seals. It can simply be unscrewed and cleaned out if blocked.

Tony from Jersey,
I usually poke a tiny pilot hole (or use a drill) in the metal case of the seal, then thread a drywall screw into the hole, then gently pry out the scew with pliers or a claw hammer or such. The seal usually just pulls right out.

Curly, I checked the vent by blowing compressed air through the filer hole, and could feel / see air come out of the vent hole. I may pull the vent off to give it a thorough cleaning anyway. I pulled the axle out again tonight and supported the bearing in a v-block, then turned the axle and checked the runnout of the axle sealing surface. It wobbles about .001". I can't find any specs for runnout between the bearing and the shaft, but I would guess that .001" is not drastic. Do you have any idea if .001" runnout is apt to cause a leak in the seal?

I probably need to replace the bearing again anyway, since the 90 wt oil leaking through it has likely washed all the grease out of it anyway.

Alvon

[Curly]

Alvon, 0.001" is "three fifths of bugger all" , I can't see that causing a problem with the oil seal. You could try the Speedy Sleeve idea while you've got the axle out.

[engineerted]

Alvon,

One of the issues that cause the axle to leaks is worn or loose running bearings. In order for the oil to leak out the axle ends it must travel past the axle seal and then past the bearing/seals. The axle bearing is a double seal type, thus if the oil is leaking past the bearing it must leak either past its seals or around the outside of the bearing past the o-ring. New bearings and new o-rings are a must to help solve the issue. Increasing the lip pressure either thru the addition of the speedy sleeve or shorting the spring will provide the best protection against leakage due to axle movement either radial or axially. This is what I had to do to solve the leaking issue with the race car.


Ted

[ventura ace]

Thanks for your inputs guys. My understanding of the seals is as follows:
1) The axle shaft lip seal is to contain the differential fluid. It has a static pressed seal on its OD to the differential case, and can be enhanced by using a sealant. The lip part, or ID, is a rotating seal that contacts the axle shaft sealing surface, and can be enhanced by using a speedy sleeve or shortening the energizing spring.

2) The bearing is a permanently lubricated sealed bearing, packed with grease, and with inner and outer seals to keep the grease from escaping. If the axle shaft lip seal is leaking, the differential oil can leak through the grease seals and wash the grease away, necessitating replacement of the bearing. The grease seals aren't meant to contain the differntial fluid.

3) The o-ring seal is a static seal that sits in a recessed groove in the differential case, and seals against the bearing OD. It is primarily a moisture seal to keep splash water from getting in behind the bearing, which could result in rust.

It's interesting that my Fiat shop manual shows that wheel bearing grease should be applied between the bearing and the axle seal. Maybe that's another anti-rust step to help prevent moisture from attacking the steel differential case.

I'm not sure why I have so much trouble with this particular axle seal. I will try shortening the energizing spring with another new seal, and if that doesn't work, I'll shop for a speedy sleeve. The sealing surface on the shaft is completely smooth, no groove. The axle diameter is 1.170" (29.7 mm). Maybe that is the problem. is it supposed to be 30mm (1.181")? The seal is identified as a 30mm seal (30 x 45 x . Maybe someone has machined the sealing surface down in the past to remove imperfections. Can someone give me an accurate measurement on the sealing diameter on a spare axle shaft laying around?

Alvon

[seabeelt]

Thanks Curly, I always thought that was some sort of casting deformity - Of course it is covered with years of muck so I really never looked that close.

[vaz124]

For this bearings you will need a special equipment for disassembly, assembly and testing the bearing. The testing is very important because if the bearing ring fell of the his place the shaft and the wheel will fell of the axle.

disassembly:


When assembling the bearing ring (fig.2 position 2) must heat to 300 degrees celsius to have time to cool to 240 degrees celsius while you put on the assembly tool.
assembly:


When evrything cool down you shoud test the bearing ring (locker, holder) like for dissasemby with force of 19600 N (2000 kg). The bearing ring (locker, holder) should stay in his position. fig.3 position 6
testing:


If you dont have this disassembly equipment you can do like next photos. Cut the bearing and his locker






assembly with home made tool:


Sorry for my english