Ring/pinion pattern check

[u2slow]

First pattern check on used 3.73s. The somewhat opposite pattern drive vs. coast suggests I need more pinion shim. I have the original 0.026 pinion shim in there. Opinions?

What are you guys doing to load the gears for a better pattern? I've seen suggestions about applying the brakes, but that's not so viable on the mopar diffs because the axle bearings are out for access the the adjusters.

 

[TwoBobsKJ]

So did you install the gears into your rear housing or did you buy a complete housing with axles, diff, gears and all?

Your answer determines what my response is to your question...


Bob

 

[u2slow]

Used gears in my housing.

In an effort to improve the pattern, I've been adding pinion shims behind the pinion gear head. I had 0.026" and gone to .030, and now .035.

According to what I've researched, that's supposed to move the contact patch toward the toe on the drive side... but so far its doesn't seem to be helping.

I'm at 0.007-0.008" backlash when I check the pattern.

 

[TwoBobsKJ]

Used gears in my housing.

In an effort to improve the pattern, I've been adding pinion shims behind the pinion gear head. I had 0.026" and gone to .030, and now .035.

According to what I've researched, that's supposed to move the contact patch toward the toe on the drive side... but so far its doesn't seem to be helping.

I'm at 0.007-0.008" backlash when I check the pattern.

Reason I asked whether housing and gears came together is that if it they did then you could just go with it the way it is. But since they're used gears in your diff...

Don't you also need to shim the driver side carrier bearing to work in concert with the pinion shim? I'm going off memory here but I thought both had to be done - but I'm certainly not a gear expert. Like Abe Lincoln said, you can't trust everything on the Internet gr_grin but I watched a YouTube video on a gear install and I remember them shimming the pinion and side bearing.

"Gear" heads smarter than me will check in I'm sure.


Bob

 

[u2slow]

Here's the video I went with...

https://www.youtube.com/watch?v=nVb5WRUfM7Y

After 4 full setups today at different pinion depths, and not getting any closer, I had to call it. :Violin: 3.55 went back in with all new bearings. It has a 500km drive in a week and needs all the break in it can get.

On the bright side, I made an adjuster tool for the carrier bearings. :gr_grin: Very glad I'd gone with a crush sleeve eliminator (Ratech #4114). I'd surely have wasted the 1 crush-sleeve I have on hand today. Definitely a few extra tools I'm looking to pickup now.

Call it a learning experience? :emotions33:

 

[TwoBobsKJ]

That's a good video - explains the process real well.

Not sure why the pattern didn't change when you changed shims...? Something is funky there. Hopefully the original gears give you the power you need for this trip and someone here can help with getting the setup correct for the 3.73's.

Bob

 

[tommudd]

So this was a used set of gears?
How many miles on them ?
Never did like installing a used gear set
Kind of like tires, once a wear pattern is set up its almost impossible to change the patter of wear .
I see what you tried to do but can't really tell how much wear there is before install
If you could of gotten a picture of them before they were pulled out would of been easier to match up ( to what they were previously )
But yes what you did should of changed some but don't think enough to really see with the naked eye maybe or I just can't see the picture well enough??

 

[u2slow]

So this was a used set of gears?
How many miles on them ?
Never did like installing a used gear set
Kind of like tires, once a wear pattern is set up its almost impossible to change the patter of wear .
I see what you tried to do but can't really tell how much wear there is before install
If you could of gotten a picture of them before they were pulled out would of been easier to match up ( to what they were previously )
But yes what you did should of changed some but don't think enough to really see with the naked eye maybe or I just can't see the picture well enough??

Yes, used gears. Leftovers from somebody who re-geared to 4.10. No idea on miles. Supposedly 06-07 vintage... the part number agrees. I know used gears can take a bit of screwing around.

Copper neverseize was my marking compound. I couldn't get anything from the crappy white grease that came with the bearing kit. Going to hunt down the nice yellow stuff for next time.

 

[Gyro]

60,000 kms/40,000 miles on those gears.From an 07.

Gyro