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Pinon Bearing Nut Torque

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Im planning on fixing my leaky 8” rear axle and I’m going to be replacing my pinion seal with a new one and also a new pinion nut. I’ve heard the torque specs with your same crush sleeve is 125ft pounds but I’ve also heard 175ft pounds so im very lost as to what i should set it to.
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Here's what I did...there is a torque setting for how much it takes to spin the pinion and make the back tire spin. I kept tightening the nut until I achieved the proper torque to spin the pinion. I cannot remember off hand what the value was, but I stayed on the low side.

When I took mine apart, I was a bit surprised how loose the nut was. Did not take much to break it.

Make sure you use a new nut that has proper sealant. I assume you'll use a Speedi-Sleeve?
 
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Discussion Starter · #5 ·
Here's what I did...there is a torque setting for how much it takes to spin the pinion and make the back tire spin. I kept tightening the nut until I achieved the proper torque to spin the pinion. I cannot remember off hand what the value was, but I stayed on the low side.

When I took mine apart, I was a bit surprised how loose the nut was. Did not take much to break it.

Make sure you use a new nut that has proper sealant. I assume you'll use a Speedi-Sleeve?
Im hoping not to have to replace my sleeve so im going to replace the seal and nut only and see what happens.
 

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1965 Mustang GT. 11.898 @ 113.646, all motor, three pedals
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Im hoping not to have to replace my sleeve so im going to replace the seal and nut only and see what happens.
You should be ok. I’ve done the same simply gunning the nut back on with a 1/2” impact and a little red loctite on the threads
 

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I don’t like crush sleeves, yes they work but we’re designed for assembly line time saving.
I used shims for my ratio change. Hint use an old yoke opened up to ease set up
 
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Im hoping not to have to replace my sleeve so im going to replace the seal and nut only and see what happens.
If you have it apart and there is any kind of a groove, use a Speedi-sleeve. Here's a picture of my groove.
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Discussion Starter · #11 ·
You should not have to do that. Can you push the drive into the tranny enough to get clearance.
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soi tried grinding some off and hitting with a hammer since I couldn’t move the driveshaft any more and these two things fell off from the drive shaft.Do i have to replace them or my driveshaft or something? The second photo is them in their original spot before they fell
 

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As long as you did not lose any of the needle bearings and they are clean, just slide them back on. Do you know the age of the U-joints? You may want to just install new ones. I got into a bad case of while you are at it and installed new bearings and cleaned and detailed the drive shaft.
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Discussion Starter · #13 ·
As long as you did not lose any of the needle bearings and they are clean, just slide them back on. Do you know the age of the U-joints? You may want to just install new ones. I got into a bad case of while you are at it and installed new bearings and cleaned and detailed the drive shaft. View attachment 869458
It seems like they’ve never been changed, where can i order some. But they fell on the dirty floor sadly, what grease can i use to stick back on once i clean them
 

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1965 Mustang GT. 11.898 @ 113.646, all motor, three pedals
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X2 on replacing u-joints. Worn joints can contribute to pinion seal leak. Replacing u-joints isn‘t difficult, but it’s not hard to screw it up. I’d encourage you to do it; maybe watch some YouTube vids first. If you’re not confident, any driveline shop can do it but they’ll all be closed until Monday.
 

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1965 Mustang GT. 11.898 @ 113.646, all motor, three pedals
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It seems like they’ve never been changed, where can i order some. But they fell on the dirty floor sadly, what grease can i use to stick back on once i clean them
Any auto parts store can get them, if they don’t have them on the shelf.
 

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It seems like they’ve never been changed, where can i order some. But they fell on the dirty floor sadly, what grease can i use to stick back on once i clean them
Last year I went to the local Advance Auto and they had them on the shelf. :) They said they knew I was coming. You should be able to get them locally at most any parts store. They are very common.
 

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X2 on replacing u-joints. Worn joints can contribute to pinion seal leak. Replacing u-joints isn‘t difficult, but it’s not hard to screw it up. I’d encourage you to do it; maybe watch some YouTube vids first. If you’re not confident, any driveline shop can do it but they’ll all be closed until Monday.
Ditto on watching youtube videos. Very simple once you watch them.
 
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Speedi-sleeves and pinion crush sleeves are two completely different things.
You cannot buy just the needle bearing cups for the u-joint. You replace the entire u-joint assembly.
You don't need to cut the u-bolts to remove the driveshaft and u-joint assembly from the pinion yoke. This must be your first time to do this job.
 

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Just did this job on the 8” on my 69…..Looks like you already got the universal apart, but I found that rotating the driveshaft a bit not only improved access to the nuts, but also brought those u-bolts to a point where they’d just barely slip out.

If you’re just replacing the pinion seal and nut you won’t see the crush sleeve - that’s buried inside the diff - folks here are talking about a sleeve made of a very thin metal that slips over the shaft to make up for a worn groove deep enough to make your leak come back….will that groove catch the tip of a sharp pick? If not, you shouldn’t need the sleeve.

Consider the procedure described in the FSM. It begins with removing the rear wheels and drums and using an inch/pound torque wrench on the pinion nut to determine the existing preload. This value is important and specified in the FSM. The FSM goes on to tell you how much more you should tighten it after installing the new seal and pinion nut.

There’s a difference between the amount of torque applied to the pinion nut to get it tighter during installation and the measurement in inch/pounds of the force required to keep the pinion nut rotating once you get it to move in the “preload testing stage.”

Many folks are comfortable and familiar enough with the job to use other methods - counting the number of threads exposed on the end of the shaft, use of impacts, etc. Remember that the goal is to get the new nut on there at the same tightness it was before plus a smidge more….That “smidge more” is detailed in the FSM but is also found in decades of guys knowing just how much tighter to hit it - but if you over-tighten it, the preload is wrecked.

I’m an FSM guy, but in fairness, the pinion nuts on most of these 55 year old cars have likely been replaced “outside” the FSM for decades. I’d start with the FSM and then, if you’re so inclined, slim down the procedure based on experience and results.
 
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