Pinion Depth

During the install, I remembered that "someplace safe" where I stashed the old pinion shims during my move. The shim pack including baffle was .039". That would have been nice to know! Here's why........
Most/Many/Some pinions have a nifty number marked with a "+", "-" or "0". These numbers indicate the best running position for the gear. This part is a little confusing. A positive number indicates the number of shims that should be REMOVED. Think of a one foot ruler that is three inches too long. To fix it, you chop three inches off. Of course the opposite would be true as well. If your ruler were -3, you'd add three inches.

The other significant number in this case 169 should have a matching number on the ring gear. This lets you know that these gears are a matched set. Buying used gears? I'd check that out! Unfortunately not all gears are marked.

My new pinion is a +6. Using the information above, we can figure that we need .003 less shims than the original + 3 pinion.

ASSUMING the original gears were setup correctly, the following will be a very good starting shim pack.

The original shim pack being .039, minus an addition .003 = .036"

If you're confused, refer to this chart which I copied from the Dana Service Manual. Take note that all possible combinations are not presented.