There seems to be quite a lot of confusing information on the web regarding how to measure the Sterling 10.5 differential pinion pre-load.

I am installing an entire rear-end from a local junkyard on my Excursion. (better 4.30 gears)
While the rear-end was in good shape and had low miles, I figured it would be best to replace all of the oil seals before installing.
(All of the brake components were removed)

The axle shaft seals were the first to get changed.

As I was fully enjoying the use of my often un-used air tools... I stupidly removed the pinion nut from the junkyard rear-end without counting the number of threads.
To make matters worse, the yolk required a 3 jaw puller to remove. The entire length of the yolk had to be pulled. It was on tight!

I inspected the bearing and race. All looked good and of course replaced the pinion seal.
Cleaned everything up, repacked the bearings, and lubed the pinion shaft and yolk splines. (FYI there is about 2qts of new diff fluid in the case)

Even with cleaned and very well lubed splines, the yolk required me to use the nut to "press" it all the way on.
And it wasnt an easy turn of the nut either!

My idea was to tighten the nut until the bearings bottomed out on the crush sleeve, then slowly tighten the nut to get the proper pinion rotational torque of 6-8 in/lbs. (used bearings)
But since the yolk was so difficult to install, I could not feel when the yolk finally met up with the bearings. I just eyeballed and wiggled until all the yolk play was gone and the backlash seemed good.
My initial rotational torque on the pinion shows about 25in/lb.

So here are my questions:
1. Do you measure pre-load with the axles in or out? Carriage in or out?
2. If you measure pre-load with the axles in.... do the new axle seals I installed add to the rotational torque value?
3. Will running the rear-end on a drill for a few minutes loosen things and get my pre-load values lower?

On a side note: I measured the pre-load from my old rear-end and it was a nice 8in/lb with the carriage and axles still installed. (no brakes of course)

I would prefer NOT to replace the crush sleeve, as it would be really difficult for me to achieve the torque required to crush it.
But I also do not want to prematurely kill my differential.

Answers and suggestions are welcomed.
(I'll do all the "you are an idiot" myself)

 

The “right” answer is to replace the crush sleeve and set the pinion bearing preload with the differential carrier removed.

That said I’ve gotten away with not doing that several times (including on the 2010 F250 that I have now).

An easy way ( but still the wrong way, the right way was discussed above) is to spin the complete differential before adding any pinion preload to see what value spinning the carrier and axles takes (say for example it takes 10in-lbs), then tighten the pinion nut until you add your desired amount of pinion bearing preload (like if you wanted 4in-lbs of pinion preload, and it took 10 before tightening the nut, then tighten to 14in-ibs of rotation resistance).
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Yes as mentioned above, the manual has you set the preload with everything out, otherwise you are allowing the load of even free moving parts of the axles, and diff to give you a false reading on your pre-load. I had a tough time with the crush sleeve too, because my rear end build was using all new FOrd parts, upgrading the carrier to the Detroit Tru-Trac, and keeping the same gear ratio, I cheated on the crush sleeve by using my shop press. You can scroll up and down to see first time fun I had rebuilding my Sterling, but here is the post of me setting the pre-load on the sleeve with teh press.


https://www.ford-trucks.com/forums/1...l#post20731116