M.pool32

I have looked through quite a few threads and I cant seem to find what I'm looking for. I picked up a used xj D30 hp. Went and bought a new oem Spicer gear set. Went from 373 to 410. I am very experience with setting up pinion depth and backlash and what not. I am a little bit stumped here though. I've set my diff up 100+ different ways and cant get the pinion depth right. When I initially set it up with the original shims to get me ball park numbers be able to dial in the correct specs, it was wayyyyyy off. Fast forward to now, I have .150 worth of shims behind the inner bearing race while is a crap ton! I still can get my gears to mesh in the center. My initial Mark's were barely even showing. It was barely showing on the heel of the drive side and barely showing on the toe of the coase side. Which would indicate to me the pinion was too far away. With all the shims it currently has its starting to get closer to center but its still off. Now, I have so many shims behind the inner race that the oil slinger is starting to contact the ring gear. According to my markings on my yellow paint, pinion is still too far. Do I somehow have the wrong gear set? Is there a carrier break where I need to buy a new one? Do I just keep adding shims behind the inner race and just add shims between the pinion gear and the oil slinger to offset it, so it wont contact the ring gear? I have never had this much trouble setting up a d30. Kinda weird. On another note. I pulled the original carrier bearings and turned them into dummies before I press on my new bearing, that way I can set the backlash correctly first. The gear side has all the shims and the other side has "zero". My last backlash check was at about 50 thousands. With the current .150 worth of shims behind the inner bearing race. I'm concerned that if I just shimmed the crap out of the pinion, I know my backlash would still have to be adjusted as to put more shims on the gear side to get it closer to the pinion. This is. I have zero adjustability to ade more. I'm maxed out.

Just a sneek peak of my D30 HP Build

4.3L XJ

You should have some shims for the large pinion race. Generally, it is marked on the pinion what shims you need to start with. Generally +.004 for instance. Those go under the large race and should set the pinion right on or near it. Then you put the small bering on and just a little tight. Then set your carrier. Generally you can start with a back lash of about .008" and have it in the ball park

M.pool32

That's the thing. That's what I did. But my pinion depth is way wayyyyyy too low and my backlash is way wayyyyy off.

4.3L XJ

Don't know what to say then without pics

M.pool32

Drive side

Coast side

M.pool32

You can see the scuff marks on the oil slinger from contacting the ring gear

You can also see all the carrier shims are one side. With 0 on the other side. Back lash is still above 50 thousands.

M.pool32

FIGURED IT OUT!!!
So, when I bought the diff, the guy had told me it had 373 gears. I didn't think much of it. I'm going to 410. I've been fighting this crap for days! After running all the part number through online searches. Turns out the original gear set up was 355. There is a carrier break for 355 and numerically lower gears. There is another carrier for 373 and numerically higher gears. Makes sense that the 373 that were installed had odd wear and chips in the teeth. My guess, the carrier was never changed out and they just set it up as close as they could possibly get it. Now it makes sense as to why my measurements are way off. Now to go and buy a new carrier. FML!

00t444e

I was getting ready to ask if you changed carriers, 3.73 geared high pinion axles were rare from the factory.