Differential Pinion Question 1973 FJ40 (1 Viewer)

[ukboneman]

I opened up the rear differential on my 1973 FJ40 and it was a mess - the oil was clearly contaminated with water, and there was corrosion on one of the carrier bearing adjusters. So, against all of my desires, I pulled it apart, removed the bearings and ordered a rebuild pack from Cruiser Outfitters. The pinion has neither a crush sleeve nor a solid spacer, just 2 shims below the rear pinion bearing race. The FSM shows a fairly elaborate method of setting the preload on the pinion using several SSTs. My question is, do I just put it all back together, torque the pinion nut to 100ish and add or replace shims to get the proper preload determined using a digital torque wrench? Seems that way to me, but I am not sure. Is there any benefit to switching to a crush sleeve or solid spacer construct? Thanks.

 

[Mark Jennings]

The shims are pinion depth.....preload on the older rigs is set with a fish scale, wrapped around a pulley (like a lawn mower pull start) ....if I remember, start out with 150 lbs ft...then use the fish scale and keep tightening until you get about 8 lbs pull...

The pulley is a Toyota tool of course, maybe slightly larger than the yoke flange....

What I’ve done on these, start at 150, give it a spin. Should be snug to turn by hand. A good firm grip...not a one finger spin (8 lbs side pull is pretty firm). Always tighten. Then smack it with a hammer (release stresses, ensure bearing cups are seated), and recheck.

If you think you went to far, loosen fully and start over...always tighten then check.

 

[ukboneman]

That is super helpful. The shims just sort of showed up when I took out the pinion, and I wasn't exactly sure where they had been, but that makes a lot of sense now. I have a digital torque wrench that can be used like a "fish scale" to spin and check resistance. Thanks for your help.

 

[B y r o n]

You don't need a crush sleeve or solid spacer. The pinion on the right is a factory '73:

Comparison of old 4.11 pinion right to new 4.10 left.

• B y r o n
• May 11, 2013

Simply reassemble as the pinion has a built in solid spacer. Follow FSM directions.

 

[ukboneman]

You don't need a crush sleeve or solid spacer. The pinion on the right is a factory '73:

Comparison of old 4.11 pinion right to new 4.10 left.

• B y r o n
• May 11, 2013

Simply reassemble as the pinion has a built in solid spacer. Follow FSM directions.

Awesome. Thanks. That's very helpful.

 

[eaj71]

I opened up the rear differential on my 1973 FJ40 and it was a mess - the oil was clearly contaminated with water, and there was corrosion on one of the carrier bearing adjusters. So, against all of my desires, I pulled it apart, removed the bearings and ordered a rebuild pack from Cruiser Outfitters. The pinion has neither a crush sleeve nor a solid spacer, just 2 shims below the rear pinion bearing race. The FSM shows a fairly elaborate method of setting the preload on the pinion using several SSTs. My question is, do I just put it all back together, torque the pinion nut to 100ish and add or replace shims to get the proper preload determined using a digital torque wrench? Seems that way to me, but I am not sure. Is there any benefit to switching to a crush sleeve or solid spacer construct? Thanks.

Haha. Yeah. Mine has no crush sleeve or spacer. Just the shims.

I am about to do this too…

did you have a spacer between the pinion gear and the bearing ?

 

[ukboneman]

Hard to remember for sure, but I am pretty sure I did not. Good luck.

 

[eaj71]

Mine did not either.
thanks