I have two different information concerning the location of the pinion depth shim:

1. "The Borg Warner model 78 rear axle assembly, like the Dana design, uses a pinion shim located between the rear (inner) bearing cup and the carrier. (Source: ASE3 - Manual Drivetrain and Axles, page 6-51)

2. Item 24 in this pic:



Here it is between the pinion gear and the rear pinion bearing.


Which one is the correct one???


for your response.

 

When I upgraded the gears in my 9 bolt it was between the bearing cup and carrier housing. If it was put on the pinion before the bearing gets pressed on that would make it a pain in the *** to set pinion depth.

 

#24 is the shim. Without a pinion depth gauge, you can only guess at the proper shim to use. Since you just about have to destroy the inner bearing to change the shim, places that rebuild diffs on a regular basis will have setup bearings. These are bearings that have the center part honed/machined out a few thousands of an inch so that it doesn't need to be pressed on and off. If the shim isn't correct, they pull it apart, slide the bearing off and use a different shim. Once the proper shim has been found, the setup bearing is removed and a new bearing is pressed on the pinion.

If your wear pattern isn't correct and you need to change the shim thickness, you're SOL if you think you can remove the bearing without damaging it. If the pattern is close enough, try living with it.

If you need a thinner shim to move the pinion outward, try crushing the crush sleeve a bit more. You set up the gears without the crush sleeve first to eliminate it's thickness. If you're already doing this without the crush sleeve then you can't tighten it up more.

 

Thanks for the replies!

At the moment the new inner bearing is pressed on the pinion and I know that the removal will destroy it.
The bearing cup is NOT pressed in the carrier housing at the moment.
I have a second cup too. I'm planning to reduce the diameter of this cup by a few thousands of a mm so that I can press it into the carrier and remove it again without any big effort. It will be used as a "service cup".

So let me state my question more precisely...:IF it will be necessary to adjust the depth of the pinion: does it make any difference where I add the shim?

I don't think so, but I want to have a second opinion to be on the safe side.

 

It goes between the pinion and the pressed on bearing.. If you have the right tools you wont destroy the bearing.. just use the one that was on your stock gears and you'll be fine

 

The manual text is correct for service, the blow up diagram is correct for a factory set-up.
The shim behind the bearing under the head can be done only if you know exactly what shim to use, the first time.
You can more easily shim the inner pinion in or out from behind the bearing cup. DANA axles are all like this. If your axle has the smaller main pinion bearing it will be the same as the DANA 35 inner pinion bearing, ie get pinion shims for a 35. If it has the large inner pinion bearing, you can use the same shims as your carrier bearings. Your housing has notches in the casting for knocking the bearing cup out to change the shims..it's not that hard, just get a nive long drift.