Dana 35 Pinion seal

I've noticed the pinion seal on my Dana 35C is slowly leaking after 155K miles. There's no apparent slop in the pinion bearing itself, so I assume I'll just replace the seal. Is the seal replacement as straight forward as it looks? Simply drop the driveshaft, remove the pinion nut, and then pull the yoke? Any tricks to pulling the yoke? Am I missing anything? Thanks -

Andy

Properly, the pinion bearing preload is determined by a crush sleeve, which is crushed down by the tightening of the pinion nut, and properly, this sleeve should be renewed every time you take the nut off, and the preload adjusted anew with the ring gear off. In actual practice, on an old one, it's probably all right to do it straighforwardly, and just tighten it a teeny bit more than it was before, to add a little more preload to the now-well-worn bearing. You should try to get a feel for how tight the bearing is before you remove the nut, and try to record how many turns it takes to get the nut off, so that when you put it back you can snug it down and set the preload by feel when you wiggle the pinion. Just remember that because this is set with a crushable sleeve, once it's crushed down you can't back up, so proceed with caution.

Obviously what I'm suggesting is not the proper way to do this, but that's how I did it on my 87, and it never gave a bit of trouble.

Make sure you have a huge pipe wrench or other device with which to hold the yoke when you loosen and tighten the nut.

Ahhhhhh....I didn't realize that the nut holding the yoke on was also the nut that preloaded the crush sleeve; I figure there was another nut behind the yoke for that. Well, I don't mind the backyard approach as long as it's reasonable. I'd like an excuse to get an 8.8 with disks, but I'd like to do it on MY timeline! :>)

Do I need to hoild the yoke when removing/replacing the nut, or can I let the ring/pinion keep the pinion shaft from turning? or will that damage it somehow? I can't imagine that I could put more torque on the shaft than the driveshaft could, but maybe I'm overlooking something....

Thanks for the tips, Matt!

Andy

If you don't hold the yoke while removing/replacing the nut, it's just going to spin. You can (may have to) use an impact to loosen it without holding the yoke but to put it back on you will need to hold the yoke and I wouldn't use an impact to put it back on.

I just had this discussion with the shop foreman at the dealership. They don't replace the crush sleeve. He said it takes about 300 foot-pounds to crush the sleeve, and when they replace a pinion seal they just torque to somewhere between 200 and 250 foot-pounds.

Which means I need a new torque wrench

I usually torque to about 210.

AndyS said:

Ahhhhhh....I didn't realize that the nut holding the yoke on was also the nut that preloaded the crush sleeve; I figure there was another nut behind the yoke for that. Well, I don't mind the backyard approach as long as it's reasonable. I'd like an excuse to get an 8.8 with disks, but I'd like to do it on MY timeline! :>)

Do I need to hoild the yoke when removing/replacing the nut, or can I let the ring/pinion keep the pinion shaft from turning? or will that damage it somehow? I can't imagine that I could put more torque on the shaft than the driveshaft could, but maybe I'm overlooking something....

Thanks for the tips, Matt!

Andy

Click to expand...

A big wrench makes it easier because pushing on the gears won't give you really firm consistent resistance. Remember the thing was put on with something like 2- 300 foot pounds of torque, and it's now nicely rusted on. You'll probably be underneath it with your feet braced to the frame and both hands on the wrench. If you're taking up slack in the differential it's hard to get a really firm "break-it-loose" yank. A big pipe wrench, blocked against some part of the frame, or against a jackstand or a block, will help a lot. and you'll definitely want some way to hold it when you reattach.

Remember, two hundred foot pounds of torque at near zero RPM is a heckuva lot of torque, more than enough to move the car.

Eagle said:

I just had this discussion with the shop foreman at the dealership. They don't replace the crush sleeve. He said it takes about 300 foot-pounds to crush the sleeve, and when they replace a pinion seal they just torque to somewhere between 200 and 250 foot-pounds.

Which means I need a new torque wrench

Click to expand...

I'll have to do that on my 44... and man those "high range" torque wrenches are expensive!!!

Thanks again, everyone.

Andy

The correct way to replace the seal on an alxe with a crush sleeve is to jack up the rear and put it on jack stands. Remove the tires. Drop the driveshaft. Then measure the force it takes to rotate the pinion. Tear everything down and replace the seal. You then tighten the pinion nut to a point where it takes 3 inch pounds more rotational force to rotate the pinion than it did before. Once the vehicle is driven for a few miles, the rotational force will settle back to where it was. This is the recommended factory method and is not hard.

I've done plenty by feel, but I now have a inch pound beam torque wrench for measuring the forces. The actual torque on the pinion nut isn't the issue, its the amount of preload it accomplishes. That is witnessed by the rotational torque.

The other thing to think about when replacing the seal is that the surface on the yoke is most likely scored and that is why it is leaking. You either need to take a piece of emery paper and smooth the surface or get a new yoke. Otherwise you are just wasting your time. You may be able to get what is called a jiffy sleeve or ready sleeve. It is a very thin cylinder of stainless steel that can be pressed over the yoke gasket surface and basically glued in place. That gives you a new smooth seal surface. It is a few thousandths larger, but well within tolerance.

I've used jiffy sleeves before for crank seals with good results - I didn't know they made 'em for driveline components too. Thanks for the tip -