Trying to find out why rear is heating up. I go for long drive and rear end gets so hot you can not touch it. I pulled cover off and can't seem to find out anything. The pattern looks ok . but don't no exactly whats is the best. Seems like ring gear pattern looks straight acoss gear except it does not go from one edge to the other. looks deep enought but the pattern stops about 1/8 inch from one edge. How hot should it get??

I had a trans temp and rear diff.temp gauges in my last truck and to my suprise in the summer while pulling my boat the rear diff. would run hotter than the automatic trans. I can't remember what temp but it got pretty hot. It may be normal. Are you haveing a problem with it or just checking it.

if you got 2 different tires on the rear it will heat up. maybe brakes also binding so that makes the rear working more. did someone have emergency brake on and never took it off.

Where's Freddie?

He will know..

pdq67

Any rear end will get hot enough that you can't put your hand on it. I need to get one of those infared thermometers to check the temp, but I would say that around 200 degrees would be normal.

It felt like the clutch packs were acting up one day. Driving car and went around a curve and the rear end felt like it came out from under the car. When i got home i crawled under to check and found nothing loose. Then i felt rear end and it was "hot". Then i starting thinking i have some kind of heating problem. My brother and I rebuilt this rear about 2000 miles ago and i pulled cover off to check for anything weard and can't find nothing. The only thing that looked different was the spider gears looked like they have been turning .

This is the function of carrier case and its spider gears and axle gears, allow the inner wheel to turn less than the outside wheel when turning.

did you put posi lube in the rear? if you got bearings too tight it will heat up also.

Put 16 miles on mine and hit 208 deg......I shifted pretty hard at the stop lights...sounds normal...hard to say without putting my hand on it.
pun intended.

Yeh i put rear end oil and that posi additive. Turning ring gear seems ok. and pinion turns good to, and have a little click between pinion and ring gear.
I did not do anything with the clutches when i did all the bearings and races.
Could there be something wrong with these?

If all else mechanically checks out, if the gear lube you used is standard stuff, dump it out and put in synthetic lube like Amsoil, it has the posi additive built into it, no extra needed. It will run cooler ! If you had access to thermal gun like they guys mentioned, would be interesting to see the difference after changing lubes. :)

I still think you are worried about nothing. You can't hold your hand on any rear end after the car has been driven. Find some way of measuring the temp and if it is below 250 then don't worry about it.

I changed oil to synthetic 85/140 with additive and going to drive and then measure temp. thanks guys.

Also i measured air pressure and evened both tires and backed the brakes off about 3 clicks on the adjuster. Might have been slight drag on brakes.