Differential Temperature?

Dave in Boise

Senior Member
Hi All,

I am wondering if the rear differential will build up any temperature when touring? I will run on a 80 degree day, around 45-50 mph and will see the center of the differential (with 600W) run to about 110 degrees.. Is this normal? The hubs run nice and cool.

Dave in Boise
 
Doesn't sound too hot at 110 deg F. Shows that the 600 w is doing it's two jobs. Cool and lube. There was an earlier discussion this morning about diff temp by Brent-in-ten-o-C. You can click on 'skip' and then click on 'Statics' to view the posts and find that one.

You can almost keep your hand plastered to a 160 deg F. metal surface. Like a black car's roof in a California sun.

skip.
 
Thanks Skip :)

I was following the discussion about vents and did notice some discussion about temperatures.. I have one of those infrared thremometers, which is good (lets me see if things are too hot) and bad (makes me worry that things are too hot) :)

I appreciate the feedback.. Was not sure if the temperature was an indicator of bad stuff happening in the rear or not.. I drained the old stuff and looked into the diff casing and things looked OK as well as "fishing" around in the old rear oil with a strong magnet showed no hard parts were being chewed up. Maybe I worry too much?

- Dave in Boise
 
A number of times people have reported that the banjo was too hot to lay there hand on it right after a differential rebuild. After several hundred miles it didn't get quite so hot.

What that tells me is the mechanic who put the rear end together did not properly set the preload on the carrier bearings. They mearly installed a nominal gasket on each side from the kit many suppliers provide instead of selecting thickness and quantity of gaskets to provide the proper preload. The bearings were probably way too tight, if not completely locked up. Henry's 40 horses broke it loose and caused the bearing mounting surface to "spin" on the hub and machine some metal off the hub. Then it ran free and much cooler. However, the bearing is partially turning on the mount, not on the bearing itself.

Just about every rear end I tear apart I find the bearing has spun on one or both hubs. If it is just one hub, it is usually the ring gear side, probably because it receives the initial torque there.

The repair is to have the hubs knurled, if there is enough metal left. Then the bearings can be pressed onto the hubs tight. A cut also has to be taken on the bearing stop to true it up and a shim added to make up for the lost metal.
Tom Endy
 
The rule of thumb on a differential is ambient air temprature plus 90-110 degrees. Lots of guys say, "it was so hot you couldn't put your hand on it!"

Well...yea, you don't want to stick your hand on something that is 190 degrees.. Your rear is in good shape temp wise.

-Abone.
 
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