Temperature of Differentials

How hot should the front and rear diffs get?

I don't have anything to gauge by and I noticed that after driving for a while (only in 2wd) they're pretty hot. (Like can't keep my hand on it.) Now my intuition tells me they're going to get hot because they're spinning so fast, but what is the 'normal' temperature?

Sounds like it maybe low on lubrication, I would pop the cover off and check.

Sounds like it maybe low on lubrication, I would pop the cover off and check.


I just changed the oil, so I know it's not low...

I've checked my diffs with an IR gun after a long steady highway run on a warm day in the summer. Temps ran in the 125 -140 F range. Definitly hotter than your hand will like but then the hand isn't that accurate.

What kind of oil are you running??

JD

I've checked my diffs with an IR gun after a long steady highway run on a warm day in the summer. Temps ran in the 125 -140 F range. Definitly hotter than your hand will like but then the hand isn't that accurate.

What kind of oil are you running??

JD


Interesting idea about the IR gun... about a month ago i refilled it with a generic 80w-90 after I noticed the oil was bad. Had a bad carreir bearing so I had it replaced today. This time I got some (i think these are the specs) 85w-140 valvoline synthetic blend. Meets the GL-5 spec, and it says it's suitable for all hypoid diffs.

Took 'er for a spin and figured i'd just check to see if the seal took, which it did. Never checked the temp of it after a drive, so I placed my hand on it and, damn, it was hot. Wondering if it's normal or if something was put back together wrong.

Should be all right with the valvoline syn. The manual calls for the 75w140 in the rear diff if you tow a trailer otherwise the 75w90 is all you really need.

How bad was the carrier bearing??? When carrier brgs went out on me, I did everything including the pinion bearings. They were on there way too.

Does your diff have the factory limited slip?

JD

Should be all right with the valvoline syn. The manual calls for the 75w140 in the rear diff if you tow a trailer otherwise the 75w90 is all you really need.

How bad was the carrier bearing??? When carrier brgs went out on me, I did everything including the pinion bearings. They were on there way too.

Does your diff have the factory limited slip?

JD

Well the rear does have the limited slip, but the bad bearing was in the front. The inner race was pretty pitted, along with many of the rollers. This was the bearing opposite of the ring gear. The other one was fine, but I replaced it as well. I didn't do the pinion bearings.