Pinion bearing preload (Detroit pinion support)

[dogsbody]

Is this a case of: fit the spacer, guess at a couple of shims, crank the nut to 200lb-or-so and turn the pinion. If it turns with slight resistance, job jone. If not, chance shims as req'd til it does.
Or am i over-simplifying...

Is there a trick for holding the pinion whilst cranking the nut up? Can i bolt the support to the housing and maybe stuff a rag between the pinion and ring gear teeth or will the stress the bearings?

[MrQuick]

Theres a special tool which is a big flat bar with a section cut out for the yoke to fit in and you just jam it up against the frame. But you can lock it up on a vise, then tighten it up that way. I've seen guys bolt a lenth of pipe into the u joint straps and jam it up on the frame.

I wouldn't jam a rag in there cause if it spins your going for a ride. Hopefully not your head into the leaf spring.

[chicane67]

The easiest way to do this...

Put the pinion support in a press and pre-crush the crush sleeve. As you do this while you are applying pressure... you can rotate the pinion support housing by hand until you feel slight resistance. Not to much resistance... as you can fine tune the pre-load when you are torquing the nut.

In reality, you want to set the pre-load with assembly lube on the bearings or at a minimum... a light coat of gear lube. You can not rely on a specific number like "200 ftlbs"... the measurement is of 'rolling inch pounds' in resistance. The proper rolling pre-load with lube is 30 - 35inlbs.

[dogsbody]

Thanks guys.
MrQuick- of course! I was looking to grip the pinion itself but the yoke looks a lot easier to get hold of! It's not in the car so i'll be testing my vise to see how well it's fixed to the bench.
Chicane67- thanks for the pre-load info, though as it's a Daytona pinion i have to use the solid sleeve & shims not the crush-type.

[dogsbody]

Well, now i've got my yoke to fit i can get on with the build-up.
It only took about 5 goes to get the shims right for the pinion preload, that assembly is complete now and bolted to the main housing. I've guessed a couple of shims to get me started on the pinion depth so next job is to play with the gear pattern.
I've welded up a simple pair of stands out of a few bits of angle iron. These bolt to the case and hold it nice and firm with the yoke a couple of inches off the bench so i can turn it easily by hand.
I have a depth gauge and some marking grease and a lot of patience. Here goes...

[chicane67]

... We're here for ya.

Post up some pic's when you get close.