Vehicle is an '01 TJ, axle is the rear dana 44. Swapped new Spicer 4.88 gears, new Timken bearings, and an ARB in. Specs were 34 in. lbs., .010" backlash, pattern perfect. Differential was fine for the first 150 miles but overheated and boiled the fluid the first time on the highway. The driver did not notice the problem soon enough and seized the rear end. I have done more than a dozen differentials and know how to set them up. The mistake here seemed to be that the TJ dana 44's have a spec of 14-19 in. lbs. as opposed to a normal 44 which is 20-40 (I couldn't find the TJ info online, no manual for the TJ, and assumed that since every other part of them is the same that the spec would be too). A few weeks ago I took it all apart and replaced the R&P and bearings again. This time specs are 14 in. lbs., .009" backlash, pattern perfect. 300 miles later the driver takes it on the highway for the first time since the newest set of gears and the fluid boils again but this time he catches it quick and it only loses 1/2 quart. Fluid is 85W-90, vehicle has an SYE/CV driveshaft and 4 1/2" RE lift. The pinion is pointed at the t-case. Is the pinion pointed too high? Do I need to switch to synthetic to keep the fluid from breaking down? WTF? TIA

What are you doing as far as preload on the carrier bearings?

Is the driver following proper break-in procedures? If the first time he had it on the highway was 300 miles after the install, I'm guessing not...

Do you have the proper oil slingers and baffles and such installed?

Housing maybe tweaked?

That's all I can think of.

Carrier bearing preload was as the manual (for my blazer which had a 44 front stock) prescribed (zero movement left to right in the housing, then add .002" shims to each side I think). Break in was drive it 10 or so miles (around town, 55 mph at the most) then let the jeep sit for a while to let the diff cool. Then repeat (break in was the same both times). We checked the rear end consistently over the 300 miles for heat and it always checked ok (again, it had never seen 70 mph). I installed all slingers that were present in the stock differential (it didn't have a slinger at the pinion head, which I am told is common for TJ dana 44's). If the housing were warped, I would think that the backlash would be inconsistent. Anyone else have any ideas?

The TJ 44 is the same as other 44s, the Tj manual states 20-40 in.lbs for new pinion bearing preload and 10-20 in/lbs for used ones. Pinion nut is 180 ft.lbs. Maybe the pinion nut is too tight?

You followed the right break in procedure, but you should be using 80w90 oil, not sure if it's a typo or if 85w90 actually exists.

Also you're right no inner oil slinger on the rear 44, they usually only put inner slingers on front axles only.

Are you sure sure that no bearings are cocked in place? once you install the pinion tap it with a rubber mallet and turn it a few times before you tighten to specs, carrier too...

Is you backlash the same at different spots on the carrier?

Are you sure sure that no bearings are cocked in place? once you install the pinion tap it with a rubber mallet and turn it a few times before you tighten to specs, carrier too...

Is you backlash the same at different spots on the carrier?


grabbing the 4 spots of backlash would determine that no?

just asking a question

You followed the right break in procedure, but you should be using 80w90 oil, not sure if it's a typo or if 85w90 actually exists.

Some synthetics are 85w90 as well as 75w90.

Do you have the ARB instructions handy? Was there mention of grinding some clearance for the oil to return from the tubes?

I've got a D44 in the rear of a TJ that spews oil out the breather, only has on the highway. Stock gears, stock housing...I just keep an eye on the fluid level. Would like to know whats causing this.

I've got a D44 in the rear of a TJ that spews oil out the breather, only has on the highway. Stock gears, stock housing...I just keep an eye on the fluid level. Would like to know whats causing this.


Same questions as above - did you do the install and do you have the instructions from ARB?

Ron, my 44 doesnt even have an ARB, its just a stock tj with 3.73's and still "burps" out the breather. Hoping the 60's im building up arent going to end up cursed by this too :(

Ron, my 44 doesnt even have an ARB, its just a stock tj with 3.73's and still "burps" out the breather. Hoping the 60's im building up arent going to end up cursed by this too :(

Well I've seen quite a few do exactly that. I don't have the time nor money of a Dana Corp. to try and solve it - but the new style ARB and the TJ 44 has increased the problem due to the shimming design. There is not enough relief clearance in the housing for oil return from the tubes when using the ARB. You have to grind a small return galley prior to installing the ARB so that oil will freeley flow between the diff area and the tubes.

I don't think you'll have any problem with your new 60's.

grabbing the 4 spots of backlash would determine that no?

just asking a question

yep, I measure the backlash at 4 opposing spots on the ring gear, 2 thou difference in the readings is normal , more than that and something can be wrong (ring gear cocked maybe or something else...)

In regards to the oil you are using, the 80 in 80w90 (what the Tj manual and ARB recommends) refers to the viscosity, maybe the 85 in 85w90 is too thick or has different thermal properties...

I installed new gears and an ARB in a TJ 44 a couple of years back and never had a problem with it, no clearancing was required.

It is 85W-90, I think the first number before the W (i.e. the 85) is what weight the oil will act like when it is cold, the second is when it is hot. The drivetrain place I bought it from said it wouldn't make a difference. The ARB manual states that some early salisbury axles have poor drainage from the driver side axle tube (the one with the breather on it) and they recommend drilling a hole to help drain that tube. Being that this is a newer (2001) rear end, and that I was pretty sure it wasn't a salisbury axle, I went past this part. It seems to me that the driver side axle tube might not have good drainage, however, and the ARB is only making it worse (because the ARB displaces more volume that used to be taken up by fluid and it has the carrier shims outside of the bearing races). I think the fixes I will try is to drill a hole through the pumpkin near the driver side bearing cap to help drain the driver side tube and to install a HP 44 cover for the greater oil capacity.

It is 85W-90, I think the first number before the W (i.e. the 85) is what weight the oil will act like when it is cold, the second is when it is hot. The drivetrain place I bought it from said it wouldn't make a difference. The ARB manual states that some early salisbury axles have poor drainage from the driver side axle tube (the one with the breather on it) and they recommend drilling a hole to help drain that tube. Being that this is a newer (2001) rear end, and that I was pretty sure it wasn't a salisbury axle, I went past this part. It seems to me that the driver side axle tube might not have good drainage, however, and the ARB is only making it worse (because the ARB displaces more volume that used to be taken up by fluid and it has the carrier shims outside of the bearing races). I think the fixes I will try is to drill a hole through the pumpkin near the driver side bearing cap to help drain the driver side tube and to install a HP 44 cover for the greater oil capacity.

By your description, you have have the newer style ARB, and I'd call thier tech line for the clearancing specs. It will help the drivers side fluid flow and possibly eliminate the problems you are having.

Racing Ron is giving you the correct answer. You MUST make a return hole on the driver's side shim-seat area of the housing or oil will collect in the driver's tube and spew out the vent and not be where it needs to be, i.e. the diff area. I've set up "more than a dozen".....I actually do this for a living, and have seen this anytime anything except an open diff is used in the "new" (external shim) 44 housing. I am also not the only person who has seen this happen, and ARB does cover it in the install manual for the Gen 2 diffs.

yep, I measure the backlash at 4 opposing spots on the ring gear, 2 thou difference in the readings is normal , more than that and something can be wrong (ring gear cocked maybe or something else...)


i just did my install on an 8.8 i had one where it was 3. i re did everything then it came back at a different spot on the ring gear. so i check it a half dozen more times. it went away. just a shitty measuring job or should i tear it apart and look deeper? :mad3:

Thanks for the replies guys, it is in the manual but is pretty deceiving as to whether it needs it or not. This one certainly does. I'm positive cutting notches for oil drainage for the tubes will solve the problem.

How much more clearance does an ARB take up? Should I be concerned about oil notches with my Eaton E-locker that I'm about to dump into a '91 G. Waggy rear 44?

How much more clearance does an ARB take up? Should I be concerned about oil notches with my Eaton E-locker that I'm about to dump into a '91 G. Waggy rear 44?

It's not an issue on your version of the D44 and Elocker - just the new style ARB and TJ 44 housings. You're fine.

i just did my install on an 8.8 i had one where it was 3. i re did everything then it came back at a different spot on the ring gear. so i check it a half dozen more times. it went away. just a shitty measuring job or should i tear it apart and look deeper? :mad3:

It might be just the position of the dial caliper that induced this error, I try to put the tip as tangent as possible to the ring gear, so, if it was a one time occurence, there shouldn't be a problem. If you were measuring the backlash at different spots on the ring gear throughout the whole set up, ie during every pinion depth value, you would've noticed several variances in the backlash and it could've meant that the ring gear was cocked.

welp shes in. drove it to work today. ran like a champ.

Would a friction modifier be recommended for a dana 44 with an ARB? Something like Amsoil might help.

With the locker and 4.88s your pumpkin sounds full. How about swappin in some fresh high capacity dif covers: http://tinyurl.com/c35zc

Then again... I am just a noob - flame away.

Would a friction modifier be recommended for a dana 44 with an ARB? Something like Amsoil might help.



No. Friction modifier is only for clutched diffs (limited slip)...

Just last month I had my diff explode, Under closer inspection there was diff fliud everywhere near my diff breather. I also have a arb in my 2003 d44 TJ.
The pinion snapped in half at the inner bearing, It looks like it was sheard right in half, like the head fell off. Superior is sending me a free new r&p that will be here hopefully friday. But I want to know what caused this. The arb and new gears were installed less than 3000 miles ago. I noticed a little leaking when it was first installed, but I figured it was from over fill. My girlfriend drives the jeep mostly, so I wasnt really paying attention to the diff breather.

Btw I really dont like the way the forums were split!!!!
Im posting on tj specific, in Jeep CJ FSJ YJ.
This is going to make it really hard to search.

Just last month I had my diff explode, Under closer inspection there was diff fliud everywhere near my diff breather. I also have a arb in my 2003 d44 TJ.
The pinion snapped in half at the inner bearing, It looks like it was sheard right in half, like the head fell off. Superior is sending me a free new r&p that will be here hopefully friday. But I want to know what caused this. The arb and new gears were installed less than 3000 miles ago. I noticed a little leaking when it was first installed, but I figured it was from over fill. My girlfriend drives the jeep mostly, so I wasnt really paying attention to the diff breather.

Btw I really dont like the way the forums were split!!!!
Im posting on tj specific, in Jeep CJ FSJ YJ.
This is going to make it really hard to search.


Does anybody know or think the arb is what caused my diff to fail.