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Pinion Nut

Actually just found this in the GM manual. Mark the threads/pinion nut/yoke before removal, check force needed to rotate the pinion, (in in-lbs) record that info, disassemble, reassemble, measure force again, making it 3 in-lbs harder to rotate than before.
 
dyeager535 said:
Actually just found this in the GM manual. Mark the threads/pinion nut/yoke before removal, check force needed to rotate the pinion, (in in-lbs) record that info, disassemble, reassemble, measure force again, making it 3 in-lbs harder to rotate than before.
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Is that exactly what the manual said? There is no real follow through on the part that says "Mark the threads/pinion nut/yoke before removal".

The rest of the instructions are one correct way to do it but it involves dissasembling the entire front axle and differential except for the pinion bearing.



Some people will recommend marking the nut/yoke and then counting the number of threads it takes to get the nut off and put it back on the same number of threads. I feel this way is asking for bearing failure.

First, you have to reuse the old pinion nut. Old pinion nuts have a tendancy to loosen which will destroy the ring and pinion instantly. Some people have staked the pinion nut to prevent this (though that involves cutting a groove in the pinion).

Second, you really have no idea what the pinion bearing preload is. The window for pinion bearing preload is pretty small (something like 5-7 in. lbs. with used bearings) and the pinion bearing preload increases A LOT when the nut is tightened a very small amount (1/64 of a turn might be 10 more in. lbs. of preload). Too much preload and your bearings will burn up and too little preload and they will skip across the races and kill the bearings.

If anyone decides to mark the nut/yoke and count threads make sure that you err on the tight side. If you don't tighten it at least as tight as it was you won't be contacting the crush sleeve and the diff will be done in very short order.




So, the answer to your question is that there is no torque spec for a pinion nut on a 10 bolt. The nut has to be tightened until the correct pinion bearing preload is attained.
 
I abbreviated, it took GM about 1 page to describe that. :) As others have said, once you mark the relationship, you put it back together so everything is lined up, then check bearing preload, in small increments getting 3 in-lbs above what it was before you disassembled.

They don't even mention the "correct" way of doing it for seal repair. I'd have to dig deeper to see if they cover pinion removal, I'm sure they do, and the crush sleeve would be mentioned.

I was surprised to see GM state this way of doing it, but I guess as long as you have an in-lbs wrench, it's perfectly legit.
 
Well I might have messed up, this is the second seal since october. The first time I changed it I tried the count the treads and mark it, but I somehow erased my mark on the nut. So I just threw it all back together. Took it up to Uwharrie, and one mudding trip. I haven't heard any funny noises or anything, butthe seal is leaking again. I wanna fix this the right way, but would prefer not having to replace all the bearings. I've been searching, and am not sure exactly how I should fix this.
 
Did you lube the seal before you installed it? I didn't the first time, ended up replacing the seal again in about two weeks.
 
Yeah but I never checked pinion preload. I just sorta tightened it back up. And now I have no reference.
 
WinslowS said:
Well I might have messed up, this is the second seal since october. The first time I changed it I tried the count the treads and mark it, but I somehow erased my mark on the nut. So I just threw it all back together. Took it up to Uwharrie, and one mudding trip. I haven't heard any funny noises or anything, butthe seal is leaking again. I wanna fix this the right way, but would prefer not having to replace all the bearings. I've been searching, and am not sure exactly how I should fix this.
Click to expand...


If you want to fix it the right way you will have to dissasemble everything and replace the crush sleeve, pinion seal and pinion nut. You can check the pinion bearings at that time. The info on how to do that is here (you can ignore most of the gear setup stuff, concentrate on the pinion setup which is ~2/3 of the way down).

You will need a torque wrench that measures inch lbs.

Its possible that the pinion bearings are toast and are causing the new seal to leak. You never know til you pull it apart.
 
WinslowS said:
Yeah but I never checked pinion preload. I just sorta tightened it back up. And now I have no reference.
Click to expand...

I've actually done that 4 times, (pull the pinion nut and not marked or measured anything) and only once had a problem. The torque on the *new* crush sleeve is huge, I just used a large breaker bar to tighten them back down. This was all before I knew better, of course. :)

If the gears aren't growling at you, you may be ok. Only time it didn't work for me, the gears made noise.
 
dyeager535 said:
I've actually done that 4 times, (pull the pinion nut and not marked or measured anything) and only once had a problem. The torque on the *new* crush sleeve is huge, I just used a large breaker bar to tighten them back down. This was all before I knew better, of course. :)

If the gears aren't growling at you, you may be ok. Only time it didn't work for me, the gears made noise.
Click to expand...

The axle in question is a front axle that likely has selectable hubs so it may last a while even if its not setup correctly (since the front end is locked in relatively infrequently).

The real question is why is the seal failing so soon? Is the surface of the yoke worn?
 
Yeah I probably need to pull it apart and check all this. Since my dad does have an inch pounds torque wrench, I'm probably going to just reset the crush, don't want to have to take it apart again after this time.
 
As mentioned, at this point you either need to pull it all apart and do a new crush sleeve or just throw it back together as is. I'd advise against trying to use the crush sleeve that's in it now, they are a one time use deal, once it's been crushed to the right spot, anything beyond that (except apparently the 3 in-lbs GM says) and it's worthless, as everything else will be off.

If you didn't lube the seal, lube the new one, and torque the yoke down tight if the leak was the only problem. You have no baseline, so you can't do this "right", other than replacing the crush sleeve.
 
Haha, and I just got around to doing it today. Couple of problems though.
-No where sold a new pinion nut. How Nessesary is that?
-The drawing you gave me was for a Dana 60, I have a 10 bolt. I also didn't see where to put the crush sleeve, I could be wrong.
-Are the torque specs the same for both axles?
 
I have bought pinion nuts from Napa before. Or try the dealership.
The crush sleeve goes in between the two pinion bearings. You could try all day and never get it to fit anywhere else.
The torque specs are different between a D60 and a 10Bolt. Look at RR&P's website, they have all the torque specs there.
 
Thanks, The Napa dude told me he didn't carry it, they have told me that before cause they were to lazy to look it up.
 
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