Archived /////// Hot Rear Hubs ? //////

[AndrewKing]

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 so I 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 tomorrow but don't know if I should given the hotter than "normal" (at least compared to my other trucks) rear hubs... . I don't want to roast a rear oil seal(s) or worse mess up some bearings..... How hot is too hot ?



Thanks in advance for you input and help



Andrew

 

[Sticks]

That is not entirely hot. Ambient temps get higher than that. If you were in the 180s after 5 miles then I might be a little concerned. If they did both hubs, the bearings need to seat after being re-torqued.

I would find a slope to drive up on and have the truck lean hard to the left, then hard to the right to make sure there is oil in the hubs - READ~ you want the center line of the differential above the top of the axle shaft a the hub... don't roll your truck over . A lot of shops fail to do this prior to releasing the truck back to the customer. Re-check your oil level after.

The likely causes of your seal that keeps going out;

1 - The tech that did the install nicked it putting the hub back on - easier than you think.

2 - The spindle was not clean.

3- The spindle has a groove or a gouge worn in it - speedy sleeve to fix it (this would be my primary bet).

4 - Improper seal install or wrong seal all together - been there, done that due to parts store sending wrong seal crossover.

5 - The tech did not replace the seal in the first place.

I presume they replaced your brakes? Oil soaked shoes can not be un-oiled.