Rear axle temps

[JIMBOX]

We crossed posted (meaning you posted your explanation while I was typing) and nothing I said was "wild judgement". If you have constant temperatures above 300F, then something is wrong--gears breaking in or not.

I don't know where you came up with the "CONSTANT" but-

Whatever makes you happy !

I'm done with this-

W.E.

JIMBO

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[CarbonSteel]

What are people trying to determine by monitoring this? I could see it if it were a tow rig and you *might* be concerned about diff temps getting too high and needing a finned aluminum cover or something even more complicated if you were burning up R&Ps or bearings...but on a Jeep, I don't see the need.

Speaking strictly for me, it is mostly curiosity, but at the same time, I like to have data points to understand what is happening within the power train. I (again speaking for only for me) do not like the relatively small oil capacity of these axles and want to see what the temperatures are in various modes of operation.

 

[Maverick909]

Have any of you seen the banks power you-tube series they did with Gail banks about the diff covers? its a great watch. he test like 6 different covers and explains everything in really good detail. I loved the series as i though about all the diff covers that get sold and all the shapes that change with them... I couldn't believe the temps they got as well with each cover! here is the link to the first part of the video!

 

[CarbonSteel]

Have any of you seen the banks power you-tube series they did with Gail banks about the diff covers? its a great watch. he test like 6 different covers and explains everything in really good detail. I loved the series as i though about all the diff covers that get sold and all the shapes that change with them... I couldn't believe the temps they got as well with each cover! here is the link to the first part of the video!

You mean the glorified sales pitch for his new axle cover?

 

[Maverick909]

You mean the glorified sales pitch for his new axle cover?

lol pretty much but the best one still ends up being the stock cover if you get ride of the banks cover. still has great information on the axles them selves

 

[engineXI]

any conclusion on what a diff temp should be?>

I just got a dealer installed rear axle and after a 5 mile drive the diff was only touchable for 1 second or less. crazy hot. checking temp tomorrow.

 

[Oletimer]

any conclusion on what a diff temp should be?>

I just got a dealer installed rear axle and after a 5 mile drive the diff was only touchable for 1 second or less. crazy hot. checking temp tomorrow.

Mine ran around 130 after gear swap to 4.88 s. After wearing in a bit.

Did they give you any directions on how to wear em in ?

 

[swampflyer]

Check and make sure it’s got fluid and correct level.

 

[wibornz]

So i decided to use a thermal temperature gun on my rear diff. It was warmer than i thought it should be, 160.
So i changed out dealer oil for 75/140 royal purple and the next time i ran the same 60 mile trip with same outside temps , rear diff was lower at 152.
So for kicks i changed it again to 75/140 lucas dino oil.
Ran same trip again a few days later 6 degrees warmer outside and rear diff was 142.
Is synthetic really better ?

I bought and installed a Fusion semi float 60 in my Jeep. Fusion called for SAE 85w-140 gear oil. I asked the tech guy why they wanted this specific gear oil run. He stated the military had done extensive testing on diff fluids and that Lucas gear oil in 85w-140 ran the coolest of all fluids tested.

My Dana 44 literally ran so hot that it cooked the electronics on the locker multiple times causing me to have to buy two new Dana 44 rear axles just so I could source the failed electronic parts.

 

[roaniecowpony]

any conclusion on what a diff temp should be?>

I just got a dealer installed rear axle and after a 5 mile drive the diff was only touchable for 1 second or less. crazy hot. checking temp tomorrow.

A new axle is going to get hotter than an axle that the gears have broke in properly. If you monitor and track the temperature over the same useage, you should see a definitive drop in temperature when the gears break-in. The aftermarket axle sellers often require you to change the oil after a break-in period. My axle shop said 500 miles.

 

[wibornz]

Speaking strictly for me, it is mostly curiosity, but at the same time, I like to have data points to understand what is happening within the power train. I (again speaking for only for me) do not like the relatively small oil capacity of these axles and want to see what the temperatures are in various modes of operation.

I agree, the Dana 44 holds about 1 1/2 quarts of fluid and in my opinion if you are using it in extreme conditions. The Dana 44 will not hold up. In the course of towing campers over 50,000 miles with my JL, I cooked the electronincs many times. To the point that they blister from the heat and failed. The locker itself was fine, the electronics and wiring not so fine.

The problem is well you can not buy the electronics for the locker. It is just recently that you can now buy the locker positioning sensor. You still can not to my knowledge buy the magnetic ring yet. In the pic you can see fluid that is baked on to the ring.

This is what the electronics look like baked by the hot diff fluid. You can see the heat blisters on the plastic. The Dana 44 does not fair well if it worked.

This is the locker position sensor. The O ring in the seal leaks and fails due to heat and gives you the service locker light. You can now buy this. They make you buy 5 at a time though. (might have changed by now)

This is a whole thread about my luck with the Dana 44 rear axle. multiple electonic failures, breaking teeth off the pinion. The Dana 44 just could not stand up to 37 in tires, and long towing days and off roading.
https://www.jlwranglerforums.com/fo...i-think-it-has-been-unreliable-for-me.118652/

 

[wibornz]

A new axle is going to get hotter than an axle that the gears have broke in properly. If you monitor and track the temperature over the same useage, you should see a definitive drop in temperature when the gears break-in. The aftermarket axle sellers often require you to change the oil after a break-in period. My axle shop said 500 miles.

I changed diff fluid at 500 miles with a gear swap, then at 1500 miles. then every other oil change.

 

[roaniecowpony]

I changed diff fluid at 500 miles with a gear swap, then at 1500 miles. then every other oil change.

I lost count and gave up counting how many times or when I change diff oil. The front got opened so often, it was always like new oil. Now that locker is fixed, it will likely be longer between openings. But to put it in perspective, I have 36k on my jeep and the axles have been opened a lot. At least 5- 6 times for the rear, and maybe a dozen times for the front.

 

[Zandcwhite]

I changed diff fluid at 500 miles with a gear swap, then at 1500 miles. then every other oil change.

Not that I care enough to actual measure temps, but the lower the gearing the larger the ring gear. In my mind that would not only reduce the capacity and increase the heat retention from the huge ring gear, but the ring sounds the oil on to the pinion and in theory could "shade" the oil being slung being so much larger. I wonder in the same circumstances if 4.56s run significantly cooler than 5.38s.

 

[roaniecowpony]

Not that I care enough to actual measure temps, but the lower the gearing the larger the ring gear. In my mind that would not only reduce the capacity and increase the heat retention from the huge ring gear, but the ring sounds the oil on to the pinion and in theory could "shade" the oil being slung being so much larger. I wonder in the same circumstances if 4.56s run significantly cooler than 5.38s.

My guess is that it's a wash. The larger pinions have more contact, which could cause more energy to be created.

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