NEW GEARS...Front diff temperature vs rear?????

[Chained Rock]

Just re geared the 80 to 4.88's and installed front and rear arbs.... I'm in the break-in phase and the front diff seams to be running noticeably warmer than the rear... to the touch it is much cooler than the t-case after 15 ro 20 minute drives... my question is does anyone have a temperature that is "normal" for diffs and t-case to run?

 

[greentruck]

I don't have any numbers, but remember the front diff is sitting right under a big hot motor. Radiant heat is almost always going to keep it warmer than the rear. A 10 to 15 degree difference seems like it could be pretty normal.

 

[nukegoat]

160-180F isn't abnormal

 

[Chained Rock]

160-180F isn't abnormal

160-180F isn't abnormal

Thanks guys, that's what I was searching for.... we've got a Moab / Colorado trip in june... driving from Kentucky so I have limited time to sort out any issues...

 

[Octous]

Just measured my front diff (had oil leak, fixed, longer story). After 60 min of highway driving (65-75 mph) the front diff was at 156 F at hottest point as measured with IR thermometer. Rear diff was at 107 F. Ambient was ~60 F

Hoping this is normal!

 

[mudgudgeon]

I'd have no issues with that.
Oils and additives typically wont breakdown until well over 100⁰C , 212⁰F

 

[Kernal]

All the above.

"had oil leak, fixed, longer story"

@Octous

Where was the leak, pinion seal?
How did you fix it (technique for tightening the pinion nut)?

Was the front diff driven low on gear oil (due to the leak)?
Was the front diff making noise (howl/whine/rumble, worse with increased speed??) before (or after) you fixed the leak?

What gears (stock or ?) are you running, rebuilt diff?
Any increase amount of metallic debris on the drain plug magnet?

What weight gear oil, conventional or synthetic?
Stock truck or modified, long uphill run when temps were checked?

Was (is) the front diff gear oil clean or contaminated?
Black/green "milk shake" from grease (or water) ---?

 

[Octous]

All the above.

"had oil leak, fixed, longer story"

Where was the leak, pinion seal?

Passenger side CV axle seal

How did you fix it (technique for tightening the pinion nut)?

Replaced seal and axle

Was the front diff driven low on gear oil (due to the leak)?

yes, but not for very long and when oil drained got out about 1.1 litres (fill is 1.6 l)
No chunks

Was the front diff making noise (howl/whine/rumble, worse with increased speed??) before (or after) you fixed the leak?

Didn't have any funny noises before leak. Doesn't seem to have funny noises now . . .but hard to tell there might be something but I think I'm just being paranoid.

What gears (stock or ?) are you running, rebuilt diff?

Stock gearing, but Nitto gears replaced 3 years ago.

Any increase amount of metallic debris on the drain plug magnet?

Nope

What weight gear oil, conventional or synthetic?

Mobil Devrac 75W-90

Stock truck or modified, long uphill run when temps were checked?

Long climb on highway 92 from hwy 280 to hwy 1. Then down hill on the otherside. Pulled into driveway and checked temperature.

Was (is) the front diff gear oil clean or contaminated?

Clean

Black/green "milk shake" from grease (or water) ---?

Clean, not contaminated by grease or water.