Hi, I have been having a rear diff. / speed / abs sensor problem when towing (not that heavy) loads. Either the rear diff. is over heating and causing the sensor in housing to fail, or vise versa. The ABS light comes on then shortly after the speedometer starts going bezerk. then the transmission stops knowing when to shift causing over heat. Put a new sensor in then its fine for awhile. Trying to get to the problem cuz sensors are getting to be an unwanted expense. gear oil is full, 80/90. Really appriciate any suggestions, nervous and on edge every time i get in it wondering if its going to get me there or not. Never happens when not towing. dont use overdrive while towing, no worn gear or rear end noises, no leaks. Thanks for any help! Reesecup, Ohio

 

There are rear diff cooling systems that can fabbed to facilitate cooling of your gear oil. But to my knowledge most of the electric pumps that these kits use are for intermittent use at high temps.

I wonder if you have a limited slip and if so, do you have the additive required for it? This may help to control fluid temp. Sorry I am not too much help.

 

Is your truck a 1/2, 3/4, or 1 ton.
When is the last time you changed your fluid.
Do you have access to a inferred heat gun?

 

Hello, truck is 460 fi, dually 1 ton. Never changed the gear oil and ive had truck for 3.5 years. no access to heat gun but could check with my mechanic about his access to one. thanks for your assistance.

 

i did pull plug out and added some gear oil last sensor change, it took about 1/3 quart at most until it ran out of plug hole located about halfway up the housing.

 

hi, not sure on the limited slip? its a 460fi dually, 1 ton.

 

IIRC the sterling rear axle takes 75-140 oil

I would change it and while you are in there look over the internal components

 

ok, the truck is currently sitting at the Kentucky nascar track. when ive changed sensors there wasnt much on metal shavings attached to the sensor magnet. To change oil i noticed no drain plug so im assuming the back plate has to come off to do this? I sell food at the race tracks, hoping i can get this thing home 4.5 hours to central ohio to take it to my service garage. The truck did this last fall and by chance happened to break down by ford dealership, they cost me 2,000 for a transmission rebuild that i dont even think i needed. Noticed the black heat protector around the sensor wires was hot, melted and in bad shape, i rerouted wires as far away from diff. housing as i could and taped the wires up good. im just wondering if somehow the sensor is shorting out somehow (possibly the tow trailer lights)? last sensor change i left trailer lights unplugged and it went on to race track without issue. I can laugh now but i also dropped the sensor bolt (hot) and it fell straight through the sensor mounting hole on top and i thought at that point the game was over lol. ws able to get a magnetic scope and the bolt came right up out of there!.... Reese