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Question on rear diff pinion flange

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Old May 27, 2025 | 08:56 AM
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Question on rear diff pinion flange

Am taking off the rear pinion nut and flange to replace a leaking seal. On the videos I watched, the flange appeared to be
press fit onto the pinion shaft. On my truck, looks like the pinion nut holds the flange on. See below:



I have it marked where the nut goes back on (num threads in = 4). will go a wee bit past when I put the nut back on.

Question: in my setup, that flange that the driveshaft mates to is held onto the pinion by the nut....correct?

thx for your insight.
 
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Old May 27, 2025 | 09:16 AM
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It's not a press fit but it is on a bit of a taper so you may have to tap on it with a hammer to remove it once you take the bolt off. Just be aware that the torque on that nut is also responsible for the bearing preload. I am not saying you have to tear down the entire rear-end to check the preload, but be sure to torque it back to the correct spec which is quite high, 160 lbs-ft is the minimum.
 
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Old May 27, 2025 | 10:21 AM
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sure enough...took the nut off with the impact and it just fell off...just the nut holds it on. cleaning things up now...

will be taking the old seal out next. will inspect the outer bearing for any pitting before putting things back together.

I have a kit to redo the bearings for the pinion but that's a bigger job. the leak is the current task at hand.
 
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Old May 27, 2025 | 10:29 AM
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Originally Posted by mackendw
........will go a wee bit past when I put the nut back on.
Assuming you got a crush sleeve, why would you tighten it more? Tightening it any more/less would be changing the adjustment. Assuming it was right on day one, I would put the nut back in the same spot.

Of course, the proper way is to replace the crush sleeve, measure the preload, and put things back together, but there is a little bit of butcher in all of us, so that is rarely done.
 
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Old May 27, 2025 | 11:15 AM
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Originally Posted by Mackenzie
sure enough...took the nut off... and it just fell off...just the nut holds it on.
I took it off while I was driving.
 
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Old May 27, 2025 | 11:31 AM
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The preload and pinion clearance is CLEARLY out of spec. there is at least 1" of free play on the pinion where the gears mesh
when turning it left/right. mind you this is with the nut off.

I'll put it back together as it was before and see where it ends up.

The seal came off fairly easily. Once I got a lip underneath it and the housing, just moved the screw driver a bit each time
giving it a twist as I went. Cleaned out the inner housing well, took out the bearing (Timken M44088) and oil slinger washer.
Both look to be in good condition. There were only 2 spots on the bearing rollers where a small bit of pitting had started.

New seal went in slick. I used a plumbing flange from homer depot that was exactly the right size. I packed the backside
of the seal where the spring was with grease to keep it stationary during install.

About to put things back together....and fill it back up with fresh gear oil.

Driveshaft cleaned and lubed too
 
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Old May 27, 2025 | 11:37 AM
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some pics of the job:






 
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Old May 28, 2025 | 03:12 PM
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Impact it down just to where it stops then torque the nut
Use Loctite, and "stake" the nut
No need for a new crush sleeve unless it ends up too tight and the bearings are already shot
 
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Old May 28, 2025 | 03:21 PM
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I used the impact to get the nut back in the same # thread position and the tick marks lined up. At some point, I'm going to take the rear end
apart and clean the internals more thoroughly, put new bearings, crush sleeve and do a more accurate installation. New fluid going in. Just
finished draining the pumpkin, cleaning it out and making the sealing surfaces ready to accept a new gasket.

btw, if you have lots of spare sealing kits for the steering box sector shaft, I'll pay shipping. Let me know if that works for you. thx a bunch!
 
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Old May 29, 2025 | 02:46 PM
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PM me your address
I am moving and might not be able to find them for a little while
But
I will
 
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