Gear pattern check

[Rainman27]

Need some advice on my gear pattern. This is a used gearset with unknown mileage that came with this new-to-me Dana 44. I'll be regearing and adding a locker next year so this setup only needs to last ~10k miles.

Option 1:
Pinion: 0.032 + 0.013
Driver Carrier: 0.143in
Passenger Carrier: 0.126in
Backlash 0.011in (out of spec)
Pinion Preload: 20 in*lb
Pinion + Carrier Preload: 30in*lb (with dry setup bearings)
Coast:

Drive:

Option 2:
Pinion: 0.032 + 0.013 (same as option 1)
Driver Carrier: 0.148in (thickest shim I have)
Passenger Carrier: 0.124in (thickest shim I have)
Pinion Preload: 20 in*lb
Backlash: 0.0055in
Pinion + Carrier Preload: 40 in*lb CCW and 60 in*lb CW. Much higher than the manual's guideline however I did add 3 thou of preload vs #1 so I'm not too surprised.
Coast:

Drive:

Tomorrow night I'll try option 3 (0.145 and 0.124) as long as the committee agrees that pinion depth is good enough. That combo should get a better amount of carrier preload although backlash is unknown.

 

[Rickyd]

None of the above,get backlash in spec before bothering with a pattern.Get a shim kit

 

[hosejockey61]

Need some advice on my gear pattern. This is a used gearset with unknown mileage that came with this new-to-me Dana 44. I'll be regearing and adding a locker next year so this setup only needs to last ~10k miles.

Option 1:
Pinion: 0.032 + 0.013
Driver Carrier: 0.143in
Passenger Carrier: 0.126in
Backlash 0.011in (out of spec)
Pinion Preload: 20 in*lb
Pinion + Carrier Preload: 30in*lb (with dry setup bearings)

Tomorrow night I'll try option 3 (0.145 and 0.124) as long as the committee agrees that pinion depth is good enough. That combo should get a better amount of carrier preload although backlash is unknown.

Used gears

A bunch of things here.

1. Used gears don't set up like new gears
2. If you didn't run a pattern before pulling those used gears, how do you know where they need to be set up? It's not to new specs, it should be where they were running in the original axle. This is because gears work harden when breaking them in and running them.
3. Trying to run a pattern without backlash in spec is nothing but a waste of time.
4. Why are you measuring "pinion and carrier" preload? Preload for the TJ is just the pinion. Later models (JL) account for the addition of the carrier.
5. The committee does not agree that you have any runnable looking pattern there whether they are new or used gears.

Here's what I would do to move forward for your temporary fix. Clean ALL the marking compound off. Take a picture of the drive side of the gear tooth. You might be able to see the wear pattern. Use that as a reference and try to match your new pattern to it. Don't bother running a pattern without backlash in spec. You don't need to worry about pinion preload until depth is established. Preload comes last.

Your pictures show that the pinion depth is way too shallow no matter new or used gears.

 

[NashvilleTJ]

Used gears

A bunch of things here.

1. Used gears don't set up like new gears
2. If you didn't run a pattern before pulling those used gears, how do you know where they need to be set up? It's not to new specs, it should be where they were running in the original axle. This is because gears work harden when breaking them in and running them.
3. Trying to run a pattern without backlash in spec is nothing but a waste of time.
4. Why are you measuring "pinion and carrier" preload? Preload for the TJ is just the pinion. Later models (JL) account for the addition of the carrier.
5. The committee does not agree that you have any runnable looking pattern there whether they are new or used gears.

Here's what I would do to move forward for your temporary fix. Clean ALL the marking compound off. Take a picture of the drive side of the gear tooth. You might be able to see the wear pattern. Use that as a reference and try to match your new pattern to it. Don't bother running a pattern without backlash in spec. You don't need to worry about pinion preload until depth is established. Preload comes last.

Your pictures show that the pinion depth is way too shallow no matter new or used gears.

Quoting Ralphie in "A Christmas Story:"

"Mike works in Ring and Pinion setup the way other artists might work in oils or clay. It is his true medium. A master."

 

[Rainman27]

Well I'm glad you guys made me recheck the wear, turns out this set is scrap. I found a couple of teeth with some pits that I missed on my initial inspection. I bought this axle completely disassembled with a blown up Trac-Lok and thought I got lucky that the R&P somehow survived pieces of spider teeth circulating through the oil. I guess I'll have a new pattern to check next week when the new set arrives.

Looking at it again I do agree that the pinion depth was way to shallow. The service manual guide seems a lot more focused on the pattern location on the tooth and not so much the pattern's shape. Reading through the Yukon install guide and watching the amazing BFH videos for the second/third time really helped.

 

[Rainman27]

New ring and pinion finally came in today. Got an initial pattern after a couple tries to get backlash correct.

This pattern:
0.062" pinion shim.
Backlash: 0.005"
Coast:

Drive:

I feel like the pinion needs to move deeper (towards the ring gear) but you guys are the experts.

What is an acceptable backlash range? I am going off the 2003 service manual which states 5-8 thou but some places online (west coast differentials and crawlpedia) state 6-10 thou.

 

[hosejockey61]

New ring and pinion finally came in today. Got an initial pattern after a couple tries to get backlash correct.

This pattern:
0.062" pinion shim.
Backlash: 0.005"
Coast:
View attachment 683222
Drive:
View attachment 683223

I feel like the pinion needs to move deeper (towards the ring gear) but you guys are the experts.

What is an acceptable backlash range? I am going off the 2003 service manual which states 5-8 thou but some places online (west coast differentials and crawlpedia) state 6-10 thou.

You are correct in your interpretation. The pinion does need to move deeper. Where you are at is a great bracket identifying to shallow. If you find a little deep now, you'll have your range to dial it in.

I think adding 5 thou will put you really close, however, if you can add about 8-10 thou it should be more definitive. Yeah that means you have to put it in and take it out a couple more times but it's worth it to get it right.

As far as your backlash specs 5-8 is the range but I have also seen 6-10 everywhere. The problem is that they don't provide enough shims to make really small adjustments, so you might be only able to get one number in that range. If you can get 7-8, that would be optimal, but if you can only get 9 or 10, I would certainly take a look at the pattern with that.

 

[Rainman27]

Good to know for the backlash.

I'd say your 5 thou recommendation was right about perfect. I will try some other carrier shim combos to get a bit more carrier preload as this combo only took about 4 medium wacks to get seated.

Pinion: 0.067" (+0.005 change)
Backlash: 0.008"
Coast:

Drive:

 

[hosejockey61]

No need to change that! Run it

 

[Rainman27]

I added 2.5 thou of preload with this pattern and got a backlash of 7 thou. Took about 10 hits to get seated. I'll go back to the other setup if this is too much preload.

Coast:

Drive:

 

[hosejockey61]

You're good

 

[Rainman27]

Ok great. Thanks for all the help.