Dana 30 Drive Pattern Check

I'm setting up gears for the first time and need some advice on my gear drive pattern. I have been fighting with this sucker for the better part of two weeks. This is the best pattern I can seem to get. I first thought it seems a little towards the toe, so I added more shims to bring the pinion closer, but the pattern doesn't go towards the root much and the contact area just gets smaller and gets really sharp define edges. I've read the pattern should have soft edges and be as centered as possible. I'd have to measure the shim pack again, but I think it's at about .035". Either way, will someone who knows more than me please help.

 

that looks pretty close ,I had problems achieving the perfect pattern with my 30 also ,,,remember that's on the front end and doesn't get much use.

 

What is the backlash with this pattern? I think I have set the pinion depth first to get the proper backlash. Then I shim the carrier to adjust final pattern. Will have to check my notebook on that again.

 

It helps to have an old bearing with the center hole enlarged so you can disassemble and adjust the pinion shims easily. Once you get the proper fit, then press on the final bearing.

 

x2 - what's the current backlash?

Not knowing where you've been, if it were mine I would try to pull a tiny bit of shim out of the pinion, readjust backlash, and see if it moves away from the top of the tooth a little more. You are close though and probably safe to run if you won't be doing heavy duty wheeling, running a front locker, etc. Otherwise I'd work on it more...the D30 housing loves to flex under load.

 

I'll take a backlash check today and post. I am planning on running a front locker, so I want to be sure that it is going to stand up to a lot of stress.

 

Here is a link to the Randy's Ring and Pinion Guide. http://www.ringpinion.com/Content/H...tions/Yukon_Installation_Kit_Instructions.pdf
Based on the photos you have provided and the pattern guide in the instructions, it appears to me that your pinion gear is too far away from the ring gear.

 

I finally got some time to run some patterns today and will posting pictures with the specs. I started at .030 on the pinon and then stopped at .040. I think the .040 is the best pattern so far, will run a .045 tomorrow to see what it looks like. Thanks for all the help on this, I think I'm starting to get it, but still don't trust my judgement on the patterns.

Almost forgot, when I say "pinion depth", I'm talking about the shim pack alone, not counting the oil baffle that resides below the shim pack.

 

Pinion Depth - .030" Backlash - .007
Pinion is definitely too shallow

 

Pinion Depth - .035" Backlash - .009
Looks better, however pinion still seems too shallow IMO.

 

Pinion Depth - .040" Backlash - .007"
I think I'm getting close, unless someone here tells me to button it up, going to run another pattern adding .005" shim.

 

I agree. My concern is that the original shim pack in the axle was only about .023" and I'm now up .040" with the new gears and still interpreting it as the pinion gear being too far away.

 

There can be huge variations between gearsets so don't worry about what was in there. Concentrate on what you have now.

 

I ended up going with .038" pinion depth and backlash of .007". I guess my setup bearings were slightly off, or just not seated completely. The .040 depth pattern looked best with the setup bearings, but ended up being a tad too deep once I pressed the actual bearings in. Now time to start all over on my Dana 44, hooray!

 

Glad you got it! Sometimes you have to compromise between drive and coast side patterns. In the front I put more emphasis on coast side pattern (assuming a low pinion carrier assembly) and in the rear on the drive side (again assuming a low pinion carrier assembly). It does get easier with practice.