Shim starting point on 8.25 regear

Hey guys/gals,

Regearing an 8.25 from essentially an empty housing, no old pinion to work off from. Was wondering if anyone had an idea of or if there is a shim minimum needed as not to damage anything for the intial pinion depth setting. I thought I had read somewhere about a measurement needed but can`t find the reference to that now, nor anything in the XJ FSM.

Thanks!

How about for anyone that has regeared the 8.25, can someone tell me what they had for a starting point from thier old shim packs?

i had to regear a D44 from an empty housing.

you basically just have to start somewhere. i don't remember if the 8.25 is shimed inside the bearing or outside the bearing. either way, until you get close, just shim it between the race and the housing until you get it adjusted pretty close. that way you don't have to pull the bearing after every single try.

when you setup the pinion you're really just going to have to take a wild guess. what you can do is place the ring and carrier into the housing so it sits centered and then slide the pinion without the bearings installed back and forth until you think it looks somewhat acceptable. then try to shim the pinion for that.

so basically slide the empty pinion in, then the carrier w/ring installed and eye it up. start shimming and adjusting from there. it took me about 8 times tearing everything back apart until i got it perfect. i would also recommend buying an extra master install kit or at least find a place to buy extra shims from. i was lucky that i had access to a dealership shop at the time, so we had tons of extra shims.

now if the shims have to go between the bearing and the carrier, once you have the shim thickness figured out by testing it between the race and housing like it told you earlier, then you can go and pull the bearings off the carrier and place the shim in between them.

hopefully that helps. while i was able to get mine set perfect, it sure wasn't as much fun as re-gearing an old axle which i can usually get perfect on the 1st or 2nd try.

hope that helps.

Thanks for the reply,

I did finally find a figure for a starting point of .020 on the pinion. I believe I am gonna have to get extra shims, but there are a couple shops near me where i can get them, and worst case there is a dealer nearby. Setup bearings are a plus on this project so far.

Won`t have to worry on the carrier because of the adjusters. Already made a tool to move those around.

My D30 should be alot easier, it`s still intact.

JM

theres a number on aftermarket gears, IE 2.345 (just a random number, no idea what the 8.25 is) that measurement is from the head of the pinion gear, to the centerline the carrier (where the caps meet the housing) get a straight edge across the bolt holes and a depth gauge, install the pinion, subtract, and your done in 1 shot

Thanks for the good tip there, worked like a charm!

tealcherokee said:

theres a number on aftermarket gears, IE 2.345 (just a random number, no idea what the 8.25 is) that measurement is from the head of the pinion gear, to the centerline the carrier (where the caps meet the housing) get a straight edge across the bolt holes and a depth gauge, install the pinion, subtract, and your done in 1 shot

Click to expand...

This method does not account for machining tolerances when the carrier bearing journals were machined. That's why they sell special tools with ways of measuring for this and calculating it into your measurement...you basically need to figure how far off the carrier center line the bearing cap was machined.

It won`t be exact, but it gives a great starting point though.

ive always been within .003 when doing it this way....chances are when you get to the marking compound your going to be changing it anyways lol