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Discussion Starter · #1 ·
Hey all,

Just recently re-geared the Jeep. I'm having some issues so I would like to go through and check that everything is up to spec.
As the title says, particularly the torque to turn the rear pinion. Currently everything is buttoned up in the rear and I'm driving. Here's my question:
After removing the rear driveshaft; Can I put my Inch Pound torque wrench on the pinion nut with the flange and pinion seal in place and get an accurate torque measurement? I know this is done during setup without the seal in place. My concern is how much friction does the seal apply to the pinion shaft, affecting the torque to turn?
I'm just trying to avoid damaging a seal and having to replace it if I can.
Thanks in advance, let me know if you need more info.
 

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Your rotating torque is measured before axles and oil are added. Would the seal drag enough to affect torque first assembling--quite possibly. That's why its checked before installing a seal. If you are carefull you might just get the seal out without damaging it. Not hard to do. Its also possible that a greased up seal wouldn't drag enough to measure the added resistance but would not be worth the risk. Try it both ways. Experiment. That seal just isn't a big ticket item.
 

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Discussion Starter · #3 ·
Your rotating torque is measured before axles and oil are added. Would the seal drag enough to affect torque first assembling--quite possibly. That's why its checked before installing a seal. If you are carefull you might just get the seal out without damaging it. Not hard to do. Its also possible that a greased up seal wouldn't drag enough to measure the added resistance but would not be worth the risk. Try it both ways. Experiment. That seal just isn't a big ticket item.
OK got it. My big worries were damaging the seal and untorquing the pinion nut, I should have added that as well as my intention to pull the axle shafts and carrier and drain the diff. Mainly because I don't have an extra crush sleeve and other spare parts handy at the moment. I just want to go over what I'm able to without making the rig totally non op.
Thanks for your input, I appreciate it.
 

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You can "cheat" a little bit if you over crush the sleeve---Install a "shim" on one end of the spacer. OR-- hammer the bulge out of the crush--works but not a great idea.
 

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The Dana service manual says to account for 3 in-lbs of additional rotational torque when the seal is installed.

I don't know all the details of your install so I'll just make a few key statements.

Depending on how many miles you drove the Jeep the initial preload may be gone already. This assumes you installed all new bearings. If you do take it all apart to check the torque to rotate I would mainly be checking that 1. there isn't too much resistance, 2. that you have some kind of preload remaining. The most common issue is that the preload was set too low and the yoke just spins freely by hand.

Hopefully you kept notes on your setup. Here is a few specs that you should have been within during your install.

Pinion Bearing Preload (DANA 44) = 20-45 IN-LBS
If seal was installed then subtract 3 IN-LBS from reading.
Differential Bearing Preload, Add below torque to reading based on gear ratio:
2.35 - 2.72 add 10-15 IN-LBS
3.07 - 3.91 add 8-12 IN-LBS
4.10 - 4.88 add 6-8 IN-LBS
5.38 - 7.17 add 4-6 IN-LBS

What kind of issue are you having anyway?
 

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Discussion Starter · #6 ·
The Dana service manual says to account for 3 in-lbs of additional rotational torque when the seal is installed.

I don't know all the details of your install so I'll just make a few key statements.

Depending on how many miles you drove the Jeep the initial preload may be gone already. This assumes you installed all new bearings. If you do take it all apart to check the torque to rotate I would mainly be checking that 1. there isn't too much resistance, 2. that you have some kind of preload remaining. The most common issue is that the preload was set too low and the yoke just spins freely by hand.

Hopefully you kept notes on your setup. Here is a few specs that you should have been within during your install.

Pinion Bearing Preload (DANA 44) = 20-45 IN-LBS
If seal was installed then subtract 3 IN-LBS from reading.
Differential Bearing Preload, Add below torque to reading based on gear ratio:
2.35 - 2.72 add 10-15 IN-LBS
3.07 - 3.91 add 8-12 IN-LBS
4.10 - 4.88 add 6-8 IN-LBS
5.38 - 7.17 add 4-6 IN-LBS

What kind of issue are you having anyway?
This is what I needed! Thank you for that guide!
Installed 4.88s last week. 2015 JKUR. I'm getting a whine/whirr starting at 18mph through 30mph. Then it comes back at 60 to 70mph becoming a whistle at that point. This is on acceleration only, not coasting. It almost sounds like a jet engine spooling up but nowhere near as loud.
We've only done the rear end so far. There's no gearset in the front. Front axle has been stripped until I can get to that.
Yesterday I yanked the axle shafts and drained the diff. No metal chunks of any sort. Just metal dust accumulated on the magnet. From what I read up, that's ok.
So I rechecked the torque to turn the pinion and I'm getting about 25 inch pounds. That seams pretty low given that I left the seal and yoke in place and didn't pull the carrier/differential out when I took the reading. However you did mention that the preload may drop after having driven for a bit. The new gear set has about 520 miles on it now so I just got past the break-in period.
Additionally, I rechecked the backlash and I'm getting .016-.017. So there needs to be some corrections made. I'm guessing these are the reasons I'm getting that noise on acceleration.
 

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Yeah the backlash is out of spec and could cause the issues you are having. Like maskale said I would take a pattern, you should definitely see an issue. Got any pictures of your pattern?

Be careful of the "close enough" mentality when it comes to doing gears. The settings are either in tolerance or out. If you stick to the values in the books you can guarantee 3 of the 4 settings are correct every time. Pinion depth is the only subjective setting that requires someone to read and interpret the pattern correctly. A lot of the time people don't have enough shims so they end up being "close enough" which leads to issues.

The 500 miles is a lot to consider the bearings still "new" however the preload seems low.

25 IN-LBS (Reading)
- 6 IN-LBS (4.88 gear ratio, if set properly)
- 3 IN-LBS (Seal)
= 16 IN-LBS on the pinion bearings

My Opinion:
Run a pattern and see what it looks like
Increase the pinion preload back within spec
Adjust the backlash within spec
Adjust carrier bearing preload to within spec
Take another pattern.

You can do all the above without replacing the crush collar or seal.
 

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Discussion Starter · #9 ·
Yeah the backlash is out of spec and could cause the issues you are having. Like maskale said I would take a pattern, you should definitely see an issue. Got any pictures of your pattern?

Be careful of the "close enough" mentality when it comes to doing gears. The settings are either in tolerance or out. If you stick to the values in the books you can guarantee 3 of the 4 settings are correct every time. Pinion depth is the only subjective setting that requires someone to read and interpret the pattern correctly. A lot of the time people don't have enough shims so they end up being "close enough" which leads to issues.

The 500 miles is a lot to consider the bearings still "new" however the preload seems low.

25 IN-LBS (Reading)
- 6 IN-LBS (4.88 gear ratio, if set properly)
- 3 IN-LBS (Seal)
= 16 IN-LBS on the pinion bearings

My Opinion:
Run a pattern and see what it looks like
Increase the pinion preload back within spec
Adjust the backlash within spec
Adjust carrier bearing preload to within spec
Take another pattern.

You can do all the above without replacing the crush collar or seal.
I'm gonna tackle it again this weekend. I painted the gears this past weekend when I was going over all the above. I'm having a hard time seeing the pattern, but yes I snapped some pics and will upload here. Maybe I did something wrong.


ForumRunner_20170705_135656.jpg



ForumRunner_20170705_135705.jpg



ForumRunner_20170705_135715.jpg
 

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No problem, doing gears is fun and I like to help.

Seems odd that your pattern is so hard to read. Maybe more marking compound or a different type. I use the GM ACDelco 1052351 stuff.

Seems like the drive side is out towards the heel which would say too much backlash, are you loading the differential when doing a pattern? Coast side doesn't look bad but it is hard to see.
 

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Sorry this is a little off topic, but how did you strip the front axle? When I did mine I just pulled the front shaft so I could do 1 axle at a time.

I assume you didn't just pull the carrier and are letting the axles spin around in there. I have a feeling that might cause an issue, or atleast some noise.
 

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No expert here, but how many miles since you regeared?

Part of the issue you could have seeing a pattern is that if you have a few miles on the jeep, the gears have broken in a bit.

What was your backlash on final assembly when you installed, and what is it now?

I had to pull my rear carrier due to snapping an axle shaft about 2 months after my regear. Knowing I didn't change anything, I just made sure my backlash was the same and my shim packs were on the same side and didn't run a new pattern. All things being equal, it should be good. Just make sure your shim packs are the same and you should be good.

I just did final torque on my pinion with the seal on, but it was lubricated well. If you are in the middle of the range there isn't enough drag there to worry about.

Pattern looks pretty close to me. You can kind of see the shiny spots, but put a bit more oil in your marking compound as suggested. Might reveal it a bit more.
 

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Discussion Starter · #14 ·
No problem, doing gears is fun and I like to help.

Seems odd that your pattern is so hard to read. Maybe more marking compound or a different type. I use the GM ACDelco 1052351 stuff.

Seems like the drive side is out towards the heel which would say too much backlash, are you loading the differential when doing a pattern? Coast side doesn't look bad but it is hard to see.
I notice that too. You can actually see where the contact is being made just from the wear even without the paint.
That pattern was with the carrier preload in place. That may not be the correct method? I'm gonna have to go over my my notes but I'm sure as heck excited to get back in there and get it right this weekend if the creek don't rise. Although here it's hot as all get out so there aren't any creeks rising.

Sorry this is a little off topic, but how did you strip the front axle? When I did mine I just pulled the front shaft so I could do 1 axle at a time.

I assume you didn't just pull the carrier and are letting the axles spin around in there. I have a feeling that might cause an issue, or atleast some noise.
You're right, we pulled the front driveshaft, yoke, carrier and shafts. Then stuffed some rags in all the housing openings to keep as much crud out as possoble.

No expert here, but how many miles since you regeared?

Part of the issue you could have seeing a pattern is that if you have a few miles on the jeep, the gears have broken in a bit.

What was your backlash on final assembly when you installed, and what is it now?

I had to pull my rear carrier due to snapping an axle shaft about 2 months after my regear. Knowing I didn't change anything, I just made sure my backlash was the same and my shim packs were on the same side and didn't run a new pattern. All things being equal, it should be good. Just make sure your shim packs are the same and you should be good.

I just did final torque on my pinion with the seal on, but it was lubricated well. If you are in the middle of the range there isn't enough drag there to worry about.

Pattern looks pretty close to me. You can kind of see the shiny spots, but put a bit more oil in your marking compound as suggested. Might reveal it a bit more.
About 540 miles on the new gear set. My buddy used his tools to gather specs (dial indicator and inch pound torque wrench).
I purchased my own last weekend to go over all the specs again and that's where I got my numbers. He's done three of these with no problems and I trust him hands down, he's no BS'r. So somethings obviously not right. One of us may have done something wrong or its out equipment. When we put the gears in he got .010 on the backlash. Now I'm getting .016 to .017 (taken on multiple teeth). Torque to turn pinion the was 35 inch pounds (iirc) on install without the seal or carrier in. I just got 25 inch pounds WITH the seal and carrier in. So again something is askew. I'd never done this before so with everything I've learned over the last few weeks I'm looking forward to getting in there and being much more involved in the gear setup. My friend's been breaking his arse with this. We hit a bunch of road blocks during this install. That parts off topic so I'll make a separate write up for that. But we're not done yet so.....

Again thank you guys.
 

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What I meant with loading the differential is that when you take a pattern if you just spin the pinion you are not providing any load on the teeth. Load which gears will always see in actual use causes separating forces and will change your pattern. Bearing pre-load is not enough. Not loading the gears is the number one mistake people make when taking a pattern.

So if you are unloaded and your pattern is towards the heel then when you load the gears it will actually creep higher towards the heel making a much worse contact pattern.

Rear axles are easy to load since you can easily slip in the axles, throw on the rotors and have someone work the parking brake while you turn the pinion. You don't even need to put the nuts on the axle retainers or rotors. They should apply enough brake to make it hard for you to turn the pinion, like two hands on an 18" ratchet, hard.
 

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Yep, you have to have some load on the pinion to do the pattern, which sounds like you did. I don't think it has to be a lot of force but I had a friend hold the pinion while I forced the ring around.

While .010 is in spec, from what I have read you should get closer to .006 if possible. I was able to do this by moving the thinnest shim.

Rotational torque measurements were trial and error for me. I practiced being smooth and trying to stay the same speed every time. Mine was actually really heavy, right at the top end of the spec with the seal. SHHHH don't tell anyone but I backed it off the tiniest amount (a reputable gear shop here in town that does a bunch of gears kind of ok'd this). 7000 miles on them and no issues...other than the broken axle, not gear related...stupidity related... :(

Another thing to note. You should when possible, not switch between different tools. Use the same caliper for all measurements, same torque wrench, same dial indicator, etc....
 

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Discussion Starter · #17 ·
This is all great info! What I had done when I took a pattern last weekend was apply some force to the ring gear with a towel in hand to get some friction. Then while applying friction with the one hand, rotate the pinion with the other hand several times forwards and several times back. I had read these instructions on another write up somewhere. I honestly can't remember what we did during the initial install. It was a long two days and by the time we got the first pattern it was late enough at night for the neighbors to complain if we made any ruckus. This project has been fighting us. Stuck bearing on the carrier, having to cut it off. Broken impact wrench. Welding together a jig to hold the rear yoke. Trying to get the crush sleeve to crush without the impact. Jacking up the threads on the new pinion and filing them back to working order. That's just nutshell'ing it. And I'm not the one who's been finding the solutions, it's been my friend. This has been an extremely educational project.
 
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