I just regeared my 2007 jk wrangler unlimited rubicon. It was my first time doing it and I did a ton of research and bought the proper tools. I put in yukon 5.13 gears with the Timken bearings install kit. I haven't had any strange noises or problems. I'm new to gears and obviously nervous about messing up my install. I'm at 115 miles into the break in and I decided to buy a Lazer thermometer to see if anything is getting to hot. During my setup of the rear I had all my specs right in the middle of the spec. My front however I had a pinion preload of 34 inch lbs. Top of spec is 35 inch lbs. This made me a bit nervous but it is in spec so why worry. I've been driving it to work and back a 15 mile each way trip. Now that I have the thermometer I am checking the Temps after each trip. The rear is at about 145 f everywhere I check it . But the front was 170 at the pinion bearing and 135 on the rest of the case on the drive to work ambient was 75 degrees f. On the way home it was 155 degrees for at the pinion and 125f at the case.
Is there a chance I have set my preload to high? Does this large of a temperature difference seem normal? Is this part of the bearing break in? Is it running hotter because it gets less airflow facing backwards?
I have another crush sleeve and could redo it if needed. I just don't want to do it if it is unnecessary . But I want my setup to last. I'm an aerospace mechanic an confident in my measurements. Running torque and measuring to the .001 is normal for me. Any help is appreciated!

 

This is from the JK service manual regarding the front Dana 44 axle:

Pinion Torque To Rotate is:

• Original Bearings: 10 - 20 in. lbs.
• New Bearings: 20 - 40 in. lbs.
• Total torque to rotate with differential installed and shafts removed: pinion torque to rotate, plus 7 - 11 in/lbs. This includes differential bearing preload.

Assuming your initial preload measurement was accurate, you are well within spec.

Don't be too concerned with your temperature readings yet. Get some more break-in miles on it.
Mine, with 138,000 miles, has always gotten too warm to be able to comfortably keep my hand flat on that area of the housing. This is very subjective, but I don't recall the readings I had when I checked it.

 

How did the mesh patterns look when you were setting up the gears?

 

the yukon manual says 22-35 I was reading 34. Odd that the manual says 20-40. I guess yukon just tighten the tolerances a bit. Feel a bit better knowing the manual says 40.

 

They we're centered well on the tooth from the face to flank nice rounded edges at the start and end of engagement . The coast slightly favored the toe and the drive slightly favored the heel. I tried many different pinion shim thickness to try to get a better pattern. In the rear I used the same thickness shim as the previous set up. Added a total of .010" to the carrier preload back lash was 6-7. On the front I increased the pinion shim .025" from the original. Had zero initial backlash and had to move the ring gear over significantly to get an in spec reading on backlash. Pattern was centered face to flank nice rounded edges again. The coast side was well centered and drive side slightly favored the toe. I just think it's odd that the installation Manual allows for tooth patterns that contact the toe or heel. Luckily mine don't. But I guess that is controlled by the machining of the housing when you only have .004" to play in for backlash it is hard to change the heel to toe pattern.

 

I took it for a drive to work yesterday it was reading 183 degrees f. Now I am wondering if my cheap beam torque wrench gave me a false reading. My buddy said to swap out the crush sleeve and try again. Assuming the bearings are not smoked.
Choices are give it another couple hundred miles and hope it cools down.
Take it apart inspect the bearings and races and reset the crush sleeve. But what do I crush it to for preload same as it reads during breakdown. Minus a couple inch lbs. It's not a used bearing but not new what's the preload spec.
Option 3 go with a crush sleeve eliminator buy new bearings and restart.
I don't want to redo it for nothing but I want the job done well. Rear has no issues and is running cooler.
I just wonder if it is broken in better because it is working and taking side loads and spinning while the front has only been spinning without ever taking a side load from pushing off the ring gear. Plus the gear oil smells fine. If I was cooking the bearings I should smell it right?