8 3/4 Axle replacement pinion Seal

Lycidias

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Hello guys,

I need to change the differential pinion seal on my 73 New Yorker, 8 3/4 Axle, #489 Case. Got the seal N5126 (Seal, Differential Pinion, 8 3/4_ #489 Case & 8 1/4_, 16,02 €)
I read a lot of good stuff here: Replacing pinion seal on 8.75 rear end

Several questions:

The Manual says:
Drive Pinion Flange Nut (Small Stem Step Pinion) . . . . . . . . . . . . . . . . . .240 ft. pounds (min) = 325NM
(Large Stem Tapered Pinion) . . . . . . . . . . . . . . . 170 ft. pounds (min) = 230 NM

--> How do i recognize which pinion i have?

I already read about the collapsible spacer and that it is recommendet to use a inch-pound torque wrench.

(4) Using inch-pound torque wrench C-685-A
measure pinion bearing preload by rotating pinion
with handle of wrench floating, read the torque
while wrench is moving through several complete
revolutions and record. This operation is very important
because preload

--> I didn't found any video or further explanation how to exactly do this. Just connect it to the flange and turn it around an around reading the shown value of torque?
--> Is the torque that low, about ~0-50 inch.lb?

I read from "Just my opinion from an old fart that's been there done that.":

Quote: "Man, after doing this stuff for over 30 years, I've never ever worried about hitting that damn high torque figure! IF you have the 89 case, mark the nut and get it back to where it was or you'll take the chance of crushing the sleeve a bit more and making the bearings too tight. On the others, do the same and do a 'feel' test to see if it still turns like it did before. Main thing is that you do not want to be too loose or too tight but on the 89, if you end up too tight, the crush sleeve probably got crushed some more and then you need to either shim it or start over and yes, you can shim it. If that happens, shimming it is a crutch but it works. That high torque stuff is for new set ups with new bearings but even then, I don't even try to hit it on the 41's and 42's and all 89's I do gets the crush sleeve eliminator kit...ie, solid spacer and then use shims to set preload."

--> So just mark it and measure the value of torque?

Thanks in advance for your help
Manuel
 
Hello guys,

I need to change the differential pinion seal on my 73 New Yorker, 8 3/4 Axle, #489 Case. Got the seal N5126 (Seal, Differential Pinion, 8 3/4_ #489 Case & 8 1/4_, 16,02 €)
I read a lot of good stuff here: Replacing pinion seal on 8.75 rear end

Several questions:

The Manual says:
Drive Pinion Flange Nut (Small Stem Step Pinion) . . . . . . . . . . . . . . . . . .240 ft. pounds (min) = 325NM
(Large Stem Tapered Pinion) . . . . . . . . . . . . . . . 170 ft. pounds (min) = 230 NM

--> How do i recognize which pinion i have?

I already read about the collapsible spacer and that it is recommendet to use a inch-pound torque wrench.

(4) Using inch-pound torque wrench C-685-A
measure pinion bearing preload by rotating pinion
with handle of wrench floating, read the torque
while wrench is moving through several complete
revolutions and record. This operation is very important
because preload

--> I didn't found any video or further explanation how to exactly do this. Just connect it to the flange and turn it around an around reading the shown value of torque?
--> Is the torque that low, about ~0-50 inch.lb?

I read from "Just my opinion from an old fart that's been there done that.":

Quote: "Man, after doing this stuff for over 30 years, I've never ever worried about hitting that damn high torque figure! IF you have the 89 case, mark the nut and get it back to where it was or you'll take the chance of crushing the sleeve a bit more and making the bearings too tight. On the others, do the same and do a 'feel' test to see if it still turns like it did before. Main thing is that you do not want to be too loose or too tight but on the 89, if you end up too tight, the crush sleeve probably got crushed some more and then you need to either shim it or start over and yes, you can shim it. If that happens, shimming it is a crutch but it works. That high torque stuff is for new set ups with new bearings but even then, I don't even try to hit it on the 41's and 42's and all 89's I do gets the crush sleeve eliminator kit...ie, solid spacer and then use shims to set preload."

--> So just mark it and measure the value of torque?

Thanks in advance for your help
Manuel
If you are only replacing the pinion seal, you should not do anything with the collapsible spacer.
489 case has large spline.
1972 8 3/4
Pinion Yoke: Monkey wrench to hold yoke. Belleville washer, install with convex side forward. Pinion yoke nut, reinstall. Turn nut until pinion yoke fully seated on pinion shaft splines. Turns with firm push and then nut stops. Final tighten: 1 ¼” ss, 3 ext, Armstrong ½” TW @ 170-170’lbs.
20190510_122352ps.jpg

Turning torque: 2” lbs, same as before. No variation in turning force thru 360°. (Check before and after install)
20190510_124253 pre load check ps.jpg
 
The correct way with a crush sleeve spacer is. Remove wheels, remove drums. Measure the turning torque of the pinion nut with inch pound torque wrench. Write that number down. Remove pinion nut, remove yoke, remove and replace seal replace yoke, tighten pinion nut stopping to check turning torque on pinion nut slowly creeping up on the turning torque number you wrote down this provides the same preload on the pinion bearings as before your disassembly. If your not using a impact and the nut is not all rusty you can try reading a torque to loosen the nut and give you a idea when you are approaching the preload number.
If you have a #741 or #742 case you can just retorque to recommended pinion nut torque in FSM.
If you have a 1 1/4" nut holding yoke on it will have fine spline yoke, the smaller 1 1/8" nut will be a course 10 spline yoke.
 
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