I have a '94 LT1 with a D36 (2.59) that has a leaky pinion seal. I have had the seal changed three times and it's still leaking. Is there something other than the seal that would cause it to keep leaking ? After the car sits for a few days, it will leave a decent sized puddle on the ground.

I can go to Huntington Beach and ask that Differential expert if you don't get an answer....

Is there any movement in the pinion?
If the bearings are bad the pinion could be running out of round opening up the seal.

Thanks for the replies. I don't know if there is any play in the bearing, but there really shouldn't be as it was replaced. I had bought the rear diff. with 40k on it to replace my 109k one and had it freshened up, the front bearing was apparently worn and was replaced. Unfortunately, the front pinion has leaked ever since and while the gentleman that worked on it has been very accomadating, I have contemplated tackling it myself.

It would seem to me that the next obvious thing to replace would be the pinion shaft itself as it could be grooved or worn, but I didn't want to play the throw parts at a problem game.

Thanks again,

i dont think that the pinion shaft would have a groove on it with only 40k on it. but if it does federal mogul or c&r bearing and seal anufacturers make a part called a speedi-sleeve. it slides over the shaft and makes a new surface for the seal to ride on.
also are they replacing the crush sleeve each time they take it apart.

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I don't know the specs off hand, but have you measured anything to see is it is within tolerance and/or round and not ovaled, etc? Are there any hairline cracks in the case?

Matthew

Well, I looked and made sure that there were not any hairline cracks, and the leak is very obviously coming from behind the dust shield. That was the bearing that was worn, so I had not thought of the possiblity of the pinion shaft being out of round. I will definetely look into this and will see about re-sleeving it or just replacing it if necessary. Thanks again for all of your help.

The seal seals against the drive line yoke installed on the pinion, not the pinion (shaft?). The seal surface on the yoke could be worn or grooved as suggested or possibly the pinion nut wasn't properly tightened and the pinion is moving. Of course that would likely ruin the pinion bearings. There is a baffle or slinger on the pinion between the bearings and the yoke. If left out it would tend to over load the seal with grease to try to control.

RACE ON!!!

Mine did the same thing. Changes the seal twice.

Luckily, Gm still stocks the yoke. Was $40 my cost. (shop price) at the time.

New yoke fixed it.

-- Joe

Thanks again, guys. The yoke is actually what I was referring to and I believe it may need replacement. All of your help is greatly appreciated, I'm tired of smelling burning diff. fluid, it stinks !

Probably the companion flange or "yoke" has a groove. Replace or repair with a sleeve. There is no crush collar in a Dana 36.Be sure to use a Viton seal. Federal #5778V