Back lash is spot on. I started with the .005 shim that was on the original pinion. New Motive gear ring and pinion. I have too increase the depth on the pinion. Can you tell be the pattern, or figure out what too increase the depth by. I was thinking to double the size of the current shim would get me close.

 

It's a trial and error thing. Just be aware as you push the pinion into the ring gear, you will need to move the ring gear away from the pinion a like amount using the carrier bearing shims to maintain your backlash.

 

Yeah I was planning to keep those shim changes similar. The carrier is the easy part. Getting that pinion depth is tricky.

 

And you gotta pull the whole thing apart to change it.

 

Edjumcate me- to my eye, that looks like the ring gear needs to go toward the pinion a bit, which you'd do
by moving a thin shim from the non- ring side of the carrier to the other- or moving the carrier bearing
adjusters an equal and opposite amount to move the carrier towards the center of the diff.

What am I seeing wrong?

t

 

Just moving the ring gear closer to the pinion will result in taking away backlash. He says his backlash numbers are spot-on at this point.

By just moving the carrier to the right, sure, his pattern will change a little. However, he will also lose backlash immediately. By moving the pinion back, he'll get move the contact pattern deeper (cone-shaped gear) but will have to move the ring gear left (away) to get correct backash again.

 

Here is a gear pattern chart

 

I think I would add .005 and recheck it
Dummy bearings are your friend
When I do Moab red rock Jeeps for my buddies (on a regular basis) I make dummy bearings out of a few new bearings
That way I don't destroy one after another after another

 

Yeah I have a set that I used originally. I thought the depth was good, but I was wrong. I’m gonna add a .005 shim behind the dummy bearings and run another pattern check

 

Yep that is exactly what happened. Lost the correct backlash moving the carrier and the pinion depth on the ring gear did not change at all. Carrier shims are correct, the pinion needs to run deeper.

 

you did not state what differential are you working on F150 8.8 or F250 Dana etc. anyways your gear pattern is way off and i do not recall any 8.8 using a 0.005 pinion depth shim , the go to shim for a 8.8 if you do not have an original shim to start with is 0.030 and then make adjustments in shim thickness up or down to produce the correct pattern . pattern should look some what like this pic i am posting

 

Sterling 10.25

 

Tell me more about these dummy bearings good sir. I had an old pinion bearing that I tried to grind the inside to make it slip off the pinion easier with no luck. My dad had told me the bearings are usually heat treated and harder than the grinder disc I was using.

 

I used a dremel with a stone grinding bit. Nice and smooth and only took a few minutes. I imagine a 60grit drum sander would work well too

 

Here is some of mine
For the ones I made, I used a die grinder with a carbide bit

These dummy bearings are worth their weight in Gold