By over tightening it, the crush sleeve will compress further, and change the relationship of the pinion gear to the ring gear.
While over tightening would crush the sleeve, it won't change the relationship of the pinion gear to the ring gear. The pinion is shimmed for pinion depth under the bearing or race. What crushing the sleeve will do is greatly increase you pinion bearing pre-load and lead to pinion bearing failure as Knuckelhead mentioned.
I'm not trying to make it sound less crucial because it is extremely important to maintain proper bearing pre-load. However, the crush sleeve is not used to set pinion depth and does not effect the gear setup.
Originally Posted by jbarrett
Hey Guys - this is a good guide and I would like to try and follow it to replace my own pinion seal leak. I had a few questions.
1. This is for a Dana30 - I have a Dana35. I'm assuming it's the same.
2. How do you truly get the pinion nut back on? The service manual says before removing the nut, you need to measure the torque required to turn the yoke several times. Can you really (and accurately) mark the location of the nut prior to removal? What's the tolerance or room for error?
3. Does the new seal need to be "seated" with a special tool? I had heard that you need a "seal set" to correctly align the pinion seal because it needs to be perfectly centered.
Originally Posted by jbarrett
So I guess I should take it to a shop. Thanks guys.
1. Same procedure for the D35 as the low pinion D30 that comes stock in non-rubicon TJs and LJs. They both use crush sleeves so maintaining bearing pre-load is important.
2. the truly accurate way to do it would be to remove the carrier, measure pinion bearing preload using an inch pound torque wrench and take note. Then reassemble with a new crush sleeve and new pinion nut and gradually crush the sleeve until achieving the desired bearing pre-load.
This is not the only way to do it. As was done with this write-up, marking the pinion nut and pinion threads and then tightening back to that same mark or just a 1/16" past works fine. You MUST use red loctite on the old pinion nut though. They are considered a one time use nut so they will want to back off if re-used without loctite.
Another method is to tighten the pinion nut to somewhere between 165-180 ft-lbs using a new pinion nut. The idea here is that it maintains a tolerable bearing pre-load since it takes over 200 ft-lbs to crush the sleeve.
I have personally tried both of these methods, one when changing the seal on my D30 and the other when changing it on my D35. I have not had any problems since.
3. Carefully tap the seal in straight and evenly. do not try and seat one side first and then the other. I used a small hammer and gently tapped around the edge of the seal until it was fully seated.
If your have some mechanic skills you can preform this job. I think the biggest problem most will run into is removing the pinion nut which usually requires a very large breaker bar and a lot of grunting as someone else stands on the brakes to keep the jeep from moving. A strong impact gun can do the job as well. Since the pinion nuts are designed to lock on the threads they can be a PITA to remove.
Since it was asked, a race and seal driver set is the tool you would use to push in seals. But as others have said there are other ways. A set is like 40 bucks or so, it would only be worth it to buy a set if you set up gears and to to press in bearing races.
Of course you don't even need the kit for races, but if your doing gees you minus well sped the 40 bucks.
CU Boulder Aerospace Engineering
Update; For what it's worth, I recently swapped out my d35 pinion seal, too, using the same procedure. I did not, in either instance, swap out the pinion nut, I used locktite. That was a budget decision, nothing more. Then I drove it 800 miles back to the Seattle area towing a trailer without incident.