Jeep JK rear Dana 44 build help

[Rockcrawler02]

Good afternoon I am currently in the process of re- gearing/installing ARB air locker in my 2008 Jk rear Dana 44. I would like to get some input on my gear pattern as this is my first time building a differential. I have found a lot of helpful videos through YouTube @TheBFHGarage and reading on various different forums.
I haven’t been able to get any feedback on any Jk forums so I wanted to see if I could get any help here if possible.




Parts that were used in this install:

New OEM Dana 44 jk non rubicon rear axle
4:10 Dana Spicer Gears NOT the Cheaper Dana SVL gears
Spicer master install kit
ARB RD117 Locker
Yukon Crush Sleeve eliminator



Current Set-Up Specs:

Pinion shim (under inner pinion bearing):0.048 in

Crush Sleeve Eliminator shims:0.0120+0.0120+0.0080=0.032+(crush sleeve eliminator which is 0.5150)=0.547 (total thickness)

Pinion Preload: 25 inch lbs

torqued pinion nut to 225 ft.lbs with red loctite

Carrier Shims:

Non Ring Gear side: OE Master shim (0.1270, ARB seal housing, ARB master shim and 0.006 shim stack)

Ring Gear side : OE Master Shim (0.1360, ARB Master shim and 0.014 shim stack)

Backlash:0.007

I tried multiple different setups using new set up bearings changing pinion depth and carrier preload and this is the best pattern I have been able to get. Was curious if anyone else who has setup Spicer OE gears has gotten a pattern similar to this. Not very pretty compared to the Gear pattern chart spicer offers.



I have also been alittle confused on backlash as well. I have heard spicer recommends between 3-5 thou, Yukon says between 6-10 thou but that’s for 5 cut gears. I have had multiple sources tell me 6-10 thou is standard on Jeep jk rear Dana 44 for backlash so not sure what’s best. Originally I had equal shim stacks of 0.010 on each side of carrier but backlash was 0.004 thou so figured that was to tight and moved 0.004 thou to ring gear side to open up backlash.



Wanted to note I am using a differential case spreader as well.



Apologize for the long paragraphs just wanted to include as much info as possible.

@hosejockey61

Thank you for your help!

 

[hosejockey61]

I have also been alittle confused on backlash as well. I have heard spicer recommends between 3-5 thou, Yukon says between 6-10 thou but that’s for 5 cut gears. I have had multiple sources tell me 6-10 thou is standard on Jeep jk rear Dana 44 for backlash so not sure what’s best. Originally I had equal shim stacks of 0.010 on each side of carrier but backlash was 0.004 thou so figured that was to tight and moved 0.004 thou to ring gear side to open up backlash.

6-10 thou is the spec.

First things first though. Don't worry about setting the pinion preload until after the proper depth has been established. Without adding preload shims, simply tighten the pinion nut down until you start to feel drag on the bearing. If you want to be very precise about it, you can check with your in/lbs. torque wrench to be sure you have enough and not too much. 25 in/lbs is too much. Shoot for 16-20. Higher torque can cause the bearings to burn up (I know the FSM calls for 20-40 but shoot for 16-20). Red loctite only when you are completing your final install after the seal has been installed and you aren't removing the pinion again.

As far as the pattern, I have a couple of questions. You stated you are using a case spreader. When you installed the locker and release the case spreader did you ensure the locker was seated using a deadblow hammer? It is very important to ensure it is FULLY seated before tightening the bearing cap bolts. That could potentially be the reason the patterns differ so much. My other thought is that if you established your pinion pre-load before depth, then it might throw something off. Lots of questions for me as for the WHY you aren't getting a good consistent pattern.

When things seem off to me I ALWAYS revert to removing everything and then double checking work. Sometimes I find a bent shim or tiny debris that got on the bearing seat. It's just better to go back through everything. In your case, I would remove any pinion pre-load shims until you are 100% certain you have the depth you want. THEN determine what the pinion pre-load shim stack needs to be.

6-10 thou backlash, 16-20 in/lbs for pinion pre-load. All of the other numbers will be what they will be once you get those set.

Lastly, when determining your pinion depth, find shallow, find deep so you are 100% certain what your bracket range is. You can easily dial in in from there.

 

[Rockcrawler02]

6-10 thou is the spec.

First things first though. Don't worry about setting the pinion preload until after the proper depth has been established. Without adding preload shims, simply tighten the pinion nut down until you start to feel drag on the bearing. If you want to be very precise about it, you can check with your in/lbs. torque wrench to be sure you have enough and not too much. 25 in/lbs is too much. Shoot for 16-20. Higher torque can cause the bearings to burn up (I know the FSM calls for 20-40 but shoot for 16-20). Red loctite only when you are completing your final install after the seal has been installed and you aren't removing the pinion again.

As far as the pattern, I have a couple of questions. You stated you are using a case spreader. When you installed the locker and release the case spreader did you ensure the locker was seated using a deadblow hammer? It is very important to ensure it is FULLY seated before tightening the bearing cap bolts. That could potentially be the reason the patterns differ so much. My other thought is that if you established your pinion pre-load before depth, then it might throw something off. Lots of questions for me as for the WHY you aren't getting a good consistent pattern.

When things seem off to me I ALWAYS revert to removing everything and then double checking work. Sometimes I find a bent shim or tiny debris that got on the bearing seat. It's just better to go back through everything. In your case, I would remove any pinion pre-load shims until you are 100% certain you have the depth you want. THEN determine what the pinion pre-load shim stack needs to be.

6-10 thou backlash, 16-20 in/lbs for pinion pre-load. All of the other numbers will be what they will be once you get those set.

Lastly, when determining your pinion depth, find shallow, find deep so you are 100% certain what your bracket range is. You can easily dial in in from there.

Thank You for the reply. Here are somethings I forgot to mention in original post:

First off I started with all new set up bearings and did many different mock- ups with various different pinion shim thicknesses. I landed at the 0.048 Pinion depth because that is what seemed to have the best pattern ( but like I stated still not anything like the spicer gear pattern chart.)

In these pictures I was going for my final install thats why crush sleeve eliminator was installed. All New bearings and races have been installed the only thing that is old here is the ARB seal housing and thats because I wanted to run a pattern with the old one I have without copper line so i didnt chance breaking the new one. Housing was cleaned thoroughly no shims were bent or out of place i confirmed that. And yes i did use a deadblow hammer along with the case spreader to confirm carrier is fully seated in housing.

Thank you

 

[hosejockey61]

Tell me what you used when you say all new setup bearings...

 

[Rockcrawler02]

Tell me what you used when you say all new setup bearings...

I bought 2 spicer master install kits and a extra set of timken bearings and races that match the ones that came with the ARB locker. I used the bearings from one of the install kits and made them setup bearings by honing the inner bores out with a flapper disc so i could slip them on and off and did the same with the extra set of carrier bearings that way i didn't chance damaging my final install bearings. The inner and outer pinion races I Installed at first and those remain in the housing as my pinion depth shims were going under the inner pinon bearing like my previous axle was set up.

All bearings and races in spicer install kits were Koyo and the Carrier bearings are Timken just like whats included with the locker.

 

[Rockcrawler02]

I bought 2 spicer master install kits and a extra set of timken bearings and races that match the ones that came with the ARB locker. I used the bearings from one of the install kits and made them setup bearings by honing the inner bores out with a flapper disc so i could slip them on and off and did the same with the extra set of carrier bearings that way i didn't chance damaging my final install bearings. The inner and outer pinion races I Installed at first and those remain in the housing as my pinion depth shims were going under the inner pinon bearing like my previous axle was set up.

All bearings and races in spicer install kits were Koyo and the Carrier bearings are Timken just like whats included with the locker.

Also i reused the OE Master shims from my old axle housing as the ones in the spicer master install kits were different

 

[hosejockey61]

I bought 2 spicer master install kits and a extra set of timken bearings and races that match the ones that came with the ARB locker. I used the bearings from one of the install kits and made them setup bearings by honing the inner bores out with a flapper disc so i could slip them on and off and did the same with the extra set of carrier bearings that way i didn't chance damaging my final install bearings. The inner and outer pinion races I Installed at first and those remain in the housing as my pinion depth shims were going under the inner pinon bearing like my previous axle was set up.

All bearings and races in spicer install kits were Koyo and the Carrier bearings are Timken just like whats included with the locker.

Ok good. The carrier bearings just get pressed on, no need for setup as they don't need to come off. With the method you chose, the only set up bearing needed would be the pinion head bearing. Sounds like you have a handle on it then.

With the pics you have posted, the two patterns are distinctly different in size and shape. That doesn't mean they are bad, just different.

Looking at your coast side first, the pattern is over toward the toe, but it doesn't run off which is good. It's more round rather than oval, but you can see where it wipes paint off toward the center of the tooth which is good. The coast side pattern has good diffusion but it looks slightly deep to me.

Looking at the drive side, it looks more oval and it also has nice diffusion. The pattern tapers up toward the top heel, but not off of the heel which is good. The right side of the pattern has the nice roundness on top and bottom which tells me the depth is good.

Since a low pinion rear axle uses the drive side of the gear, we want to favor the drive side. Luckily your drive side is the better of the two patterns. With what you have shown me, I would say this is an acceptable pattern to run. Anytime somebody asks me to read a pattern, I always ask for the shallow and deep patterns to ensure we are where we want to be. Anytime I see a weird pattern like yours I always want to ask the questions I did before commenting on the pattern to ensure all variables have been accounted for. Good job.

 

[Rockcrawler02]

Thank you for your help sir. I was just going back thru some of my trial setup photos and wanted to include them.

Pinion Depth:0.049
Carrier shims were the same

Backlash:0.005-0.006

I know marking compound was a-little to thin in these was still learning the compound to gear oil ratio!

 

[Rockcrawler02]

Thank you for your help sir. I was just going back thru some of my trial setup photos and wanted to include them.

Pinion Depth:0.049
Carrier shims were the same

Backlash:0.005-0.006

I know marking compound was a-little to thin in these was still learning the compound to gear oil ratio!

View attachment 643574View attachment 643575View attachment 643576

 

[Rockcrawler02]

Ok good. The carrier bearings just get pressed on, no need for setup as they don't need to come off. With the method you chose, the only set up bearing needed would be the pinion head bearing. Sounds like you have a handle on it then.

With the pics you have posted, the two patterns are distinctly different in size and shape. That doesn't mean they are bad, just different.

Looking at your coast side first, the pattern is over toward the toe, but it doesn't run off which is good. It's more round rather than oval, but you can see where it wipes paint off toward the center of the tooth which is good. The coast side pattern has good diffusion but it looks slightly deep to me.

Looking at the drive side, it looks more oval and it also has nice diffusion. The pattern tapers up toward the top heel, but not off of the heel which is good. The right side of the pattern has the nice roundness on top and bottom which tells me the depth is good.

Since a low pinion rear axle uses the drive side of the gear, we want to favor the drive side. Luckily your drive side is the better of the two patterns. With what you have shown me, I would say this is an acceptable pattern to run. Anytime somebody asks me to read a pattern, I always ask for the shallow and deep patterns to ensure we are where we want to be. Anytime I see a weird pattern like yours I always want to ask the questions I did before commenting on the pattern to ensure all variables have been accounted for. Good job.

Here was another setup:

Pinion shim 0.045
Backlash:0.006

 

[hosejockey61]

Yeah I think you're good to go

 

[Rockcrawler02]

Yeah I think you're good to go

Thank you for your help. Pattern still seems off where it should be to me being that it appears the drive side is closer to the heel of the tooth. Almost looks like it runs off heel on first tooth.Pattern just doesn't seem what one would expect with all new parts and OEM quality spicer gear set.

Ive been debating whether it would be worth it to order a T&D Pinion Depth Checker to confirm pinion depth especially since i started with a bare housing . I probably tried 10 or more various pinion shims but i regret not recording all of those along with pictures of set up to go back and review.

 

[hosejockey61]

Pinion depth tool will do you no good. They get you a good starting point is all. You're beyond that. If you saw it shallow and deep, and you're in between there, then you're good to go.

 

[Rockcrawler02]

Pinion depth tool will do you no good. They get you a good starting point is all. You're beyond that. If you saw it shallow and deep, and you're in between there, then you're good to go.

Ok So any idea on what would be the cause of of the weird pattern? Gear quality? Issue with the housing?

 

[hosejockey61]

Ok So any idea on what would be the cause of of the weird pattern? Gear quality? Issue with the housing?

Sometimes that's just the way they set up. In a perfect world, patterns set up right in the middle of the tooth. Rarely does that happen though. Spicer gears are usually pretty consistent, but yours isn't on this case. Doesn't make it wrong, just not what you had hoped for.