axle leak

[Guest GreazMonkY]

so a buddy noticed that i had a drip from my axle the other day, not from the back cover, but from the front. i don't remember what that seal is. and how to replace it. i'm having a brainfart, can someone help

[502ci]

Are you referring to "pinion seal"? That's in the front of the rear end where the driveshaft connects to it...it has a crush sleeve type of seal which would have to be replaced...and it's not the easiest to do from what I have read or have been told.

 

Mine is actually leaking also and needs replaced but I have been holding off because I'm looking at ordering a whole new rear end soon.

 

I'm sure someone will chime in and give you an actual answer unlike mine...

[zmanabba]

That is your pinion seal if I understand your description correctly. You will need to pull the drive shaft and remove the nut on the yoke (1 1/16 if I remember right). Then you can pry out the seal. The way to do this correctly however is to pull the ring and pinion out and change the crush sleave along with the seal to make sure you retain pre-load on the bearings. But the times I have had to change the seal I have just popped the seal out and made sure I had the same pre-load on the bearings going back together. Hopefully the nut hasn't backed out on it's own or you have bad pinion bearings. The seal could be your early warning that something else is going on. I did have one one my 70 that the nut just backed out so I had to guess on the pre-load on the bearings. I must have guessed right because that was 2 trips to Hot August Nights and an engine ago lol. Maybe someone else has a more scientific way to check the pre-load. The specs in the book are for when the ring gear and the rest of the differential aren't hooked up. I hope I didn"t scare/confuse you. 9 times out of 10 it's fine. This is why you should never have coffee this late in the day. LOL David

[zmanabba]

Even in my caffine induced trance Bill typed quicker than I did LOL. Bill love your car you are running the times I want to...probably help if I take out the 2.73 gears. LOL David

[502ci]

I see I beat you by only seconds on the response but I gave basically no helpfull info...

[wallaby]

Bla Bla Bla....you guys are cracking me up.

[Chevyss]

I've always wanted to do the pinion seal replace, but never had one leak. Good luck.

[zmanabba]

Well this sounds like a win-win. Royce how soon can you be on the plane to Del City to replace GreazMonkY's pinion seal?

[72MC]

Even after you change the pinion seal there can be a leak. One final step on reinstallation of the pinion yoke onto the pinion is to put some black RTV on the splines of the pinion and the pinion yoke and slide together. Reinstall pinion yoke nut and this should make sure there is no leaking through the splines. In my haste, forgot this step on a freshly built rear once and it leaked where stated. Doesn't need to be gobbed in there, just a nice film on both set of splines. - Dave

[overdrive]

The spline sealant is more good advice. You can mark the nut and case to get the nut tightened back to the same torque value, if you don't replace the crush sleeve.

 

Dan.

[bdk70monte]

I had this happen to my 70 MC when I first bought it too actually. It turned out it was over filled with gear oil. They must have filled the rear with gear oil when it was out of the car and standing on it's end. When we pulled the plug to check the fluid level, since it had been leaking, it came pouring out. Now that I have the correct amount of gear oil in it, it hasn't leaked at all since. I doubt this is your problem, but just wanted to throw it out there since it can happen.

[wallaby]

There is also a vent on top of the axle tube to release excess pressure as the oil heats up during use. There should be no pressure in the rear. I have seen these vents get clogged and under pressure, oil will find a way out.

[Mikstudie]

Mark the nut or count revolutions,buy a SPEED SLEVE for the pinion yolk before reinstall and presto no leak.

[wallaby]

Ditto that. I have used speedi-sleeves many times with great results. Probably the most common application is repairing the sealing surface of harmonic balancers, but they work anywhere there is a shaft seal, and they will far outlast the original part.

LINKY

[CrazyDavey]

Ditto!!! Ditto!!! you provincial putz.....

[Winston Wolf]

Don't stress too much on the crush sleeve and bearing tension, you can check it with an inch pound torque wrench on the pinion nut before you take it apart and get it close enough to the same preload with that torque wrench when you put it back together. If it's close, your bearings will be fine. Preload changes as the bearings wear in, so it's not brain surgery. Taking out the carrier will take a 1 hour job and turn it into a 1 day job; and to crush a new sleeve takes approx 150 ftlbs of torque, so you need a air wrench or long bar (not feasible on jack stands). Check the surface of the yolk for any burs or wear, if there is none, I wouldn't bother with the speed sleeve. Be sure to put some silicone RTV around the outside metal part of the seal where it contacts the pumpkin so you don't get leakage there.