Andrew King

HI All,

I have a 1993 W250 w/ Cummins diesel and Auto Trans.

I seem to have a problem with the Right (Passenger) side oil seal in the rear axle breaking and leaking fluid out the rear drum.

After having the shop fix it for the second time, I decided to see how warm (or hot) the rear hubs were getting.....To my horror the rear hubs were HOT (compared to my other trucks....similar first gen 3/4 ton w/ Cummins engines).

I took it back to the shop for them to feel how hot the rear hubs were and they told me "it was normal to be warm"........Warm yes but HOT?

Anyways, I tried to be scientific about it and took a non contact IR thermometer to measure hub temps after driving my truck....drove it about 5 Miles at 60 MPH then about 5 miles in town and pulled over to shoot the temps....

These are the temps I got (LATE night driving so no sun to heat the metal up): (all figures in degrees F)

Truck Body Temp - 66.9
Left rear hub - 108
Right Rear Hub - 114.4
Right Front hub - 83.9
Left Front hub - 82.7

NOTE: Truck was unloaded except for a ladder rack and empty 100 gallon fuel transfer tank.

Are the rear hub temps "normal" ?....Drums were "cool" compared to the actual hub so rear brakes are not dragging.

(NOTE: Rear gear oil level is fine)

I was going to drive the truck 150 Miles on Wednesday but don't know if I should given the hotter than "normal" (at least compared to my other trucks) rear hubs.

Thanks in advance for you input and help

Andrew

Diesel Dave2

Hmm...I was thinking brakes...But you said they are not dragging...Wonder if the pre-load on the wheel bearings are to tight...

joem

my original drum brake Dana 70 ran hot too- oil burned me when I cracked the cover off. Then I broke the pinion teeth... My new Dana 70 seems to be holding up ok, but no expectations on this one either. Im keeping my eyes open for a Dana 80

patdaly

I don't see this as being terrible, delta temps from front to back of 20ish isn't an indicator of a problem in my book. I would wonder though where the temps would stabilize at, which would be much more than 5 miles driven.

Perhaps take a loop, stop every 10 miles, and record the hub temps again.....

TRWilliams

I have the same truck and the same problem. In 2013 the rear axle bearings went bad and burned up. Now, 2014 the rear bearings went bad one after the other and it made the hubs searing hot. So that maybe something you might consider.

Robert Rausch

I had a problem with my right brake drum getting way too hot, (I had a brake-drum rear-axle then). It would smoke and be too hot to touch. I traced it to the fact that I had to back down a steep driveway once a week, and in braking, the right self-adjustment mechanism just adjusted that side way too much. I stopped backing down that driveway and the problem went away.

TRWilliams

So it was only when you backed down that driveway. Let me ask what you think about my new problem because it seems similar. The bearings went bad on both sides of my rear axle. I replaced all the bearings. Now the hubs are still getting hot, so I checked the brake drums and they are searing hot you can't even touch them. That is only from normal driving around.

BILTIT

That is not normal. You need to check the wheel bearing nut torque, brake adjustment etc. It is possible the wrong bearing/race pair has been used, heard of someone else having this happen.

Robert Rausch

Ditto what Derek says. There is friction somewhere where there shouldn't be. When you jack up the rear of the truck with it in N can you turn the wheel/tire around easily? You should be able to turn each wheel/tire with that tire jacked up and have only a little dragging.

NJTman

Yes, that was me.

https://www.dieseltruckresource.com/...t=bearing+mind

What I would do ..... before anything else.... is back the adjusters off completely, so there was absolutely zero drag on the drums. Drive the truck again, and see what you get.

There also could be an issue that J. Martin just had where his adjusting lever for the parking brake was not returning to where it should.