differential temp

[Twisty]

How hot should the diff get on a sterling 10.25 axle (or D60 or 14b)?

The reason I ask is I was coming home tonight and my truck has a vibration between 25-40 mph.  When I got home I was wiggling the driveshaft and noticed that it was a little warm. I felt back to the diff and it was way warmer than I expected.  I had my hand on there for 10 seconds, and had to remove it due to discomfort.  I do not have a temp gauge so I can't get an exact measurement.  I topped off the diff about 4 months ago and it hasn't really been leaking any. 

How hot is too hot?  I have honestly never felt a diff after driving 30+ miles so I have no idea.


And regarding the vibration, I found a sloppy u-joint which I hope is the culprit. 

[jps4jeep]

My best guess is it shouldn't get above 180* but I really don't know...


I googled diff fluid break down and this is what I found

a general rule of thumb is that the rate of oxidation doubles for every 10°C (18°F) rise in temperature above 75°C (165°F).

I am not sure on the validity of it

[jason m]

They can get hot and even to the point you cant leave your hand on it. Thats why alot of the dana 80's have AL covers factory with fins.

What I would do is replace the U-joint and tak eit for a good drive. If its still real hot after that then pull the cover and look for the obvious. If nothing then run it till it blow's up

You could follow around other trucks and when they stop you can feel there rear ends

Jason.

[jps4jeep]

You could follow around other trucks and when they stop you can feel there rear ends

Jason.

not sure if the driver would appreciate it.. unless it's a hot chick..

[Krome]

I would imagine pretty hot, as they take 80w-90

[Technohead]

After a few minutes on the road they can get too hot to touch. I've noticed this on many different vehicles/axles. They can get hot enough to vaporize water.

[Twisty]

Mine wasn't that hot! 

Judging from what everyone said, I guess its fine.

I got new u-joints too.  I will put those in sometime after work.   

[Casey L]

My diff measured 170* with my infrared thermometer while towing.   I was concerned so I did some research and 220-240 is normal for a differential (From my internet research on forums)

I have a thermometer you can borrow tim, let me know.

[Twisty]

Well I just finished putting new u-joints in.  Both had slop.  One of them had needle bearing dust.  Not actual bearings.  Now I know where my squeak/vibration was coming from.