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I have a '04 F250 that I recently bought with I believe a 10.5 " Ford rear axle. While investagating a noise coming from the back of the truck the other day I found the diff (especially the front pinion area) to be hot. Turns out the noise was a ebrake shoe that had froezed up when parking my camper on a hill. I resolved that issue but the diff is still getting hot after setting all night then driving just 5 miles. I pulled the filler plug and checked the oil level. Was able to get maybe 1/2 qt. into it. The oil in there was still clear. Truck has only 75K on it. I don't notice any chattering in the corners. Theres also no evidence of leakage. From I have read this axle should be bullet proof.
Anything else I can check??? From what I here this may be very, very expensive to rebuild. What choices do I have?
Here is what I would do:
Pull the cover and make a visual inspection, If all look's well.
Refill with Royal Purple Max Gear. Temp will drop a lot.You can also add a Larger rear cover for more cap. All axle's run hot, In the winter they melt snow and steam but we never notice. Don't worry It's most likely No Problem. That is a good axle.
Wanted to add: You can go the next step and unbolt the driveshaft,Pull axle Shaft's (only) and check the drag on the pinion and feel thats its movement is smooth.
You might want to check your pinion bearing before you fill it with new fluid. If its getting hot around the front of the housing the bearing could be going.
mine was making a noise when i let off the gas and coasting, found out it was pinion bearing, also the diff. was getting hot. wouldn't hurt to check. let us know what you find out.
They may run hot but I think running a cold truck 5 miles not pulling anything and its hot to thankse touch something is creating a lot of friction. Thats a big mass of metal to heat up. So I need more details on how to determine if that
pinion bearing is gone. Does someone know the preload? Why would one fail this early on a axle as heavy duty as this with only 75k miles
They may run hot but I think running a cold truck 5 miles not pulling anything and its hot to thankse touch something is creating a lot of friction. Thats a big mass of metal to heat up. So I need more details on how to determine if that
pinion bearing is gone. Does someone know the preload? Why would one fail this early on a axle as heavy duty as this with only 75k miles
thanks
If you just got the truck ,You have no idea what happened to that rear in the past, the 10.5" rear is good but .Who knows it's history?, Was the rear rebuilt ? Was the rear changed ? Used rear ?
It could be the reason it was sold in the first place. If you don't know how to check it, You can't fix it.Take it to a rear end shop if you are That Sure its running Super Hot something is wrong. Pay now Or Pay Later.
Note : The 10.5" sterling uses a crush sleeve to set pinion load,if someone changed a pinion seal wrong that's all it takes.
Typical case temps after running even short distance are in the 140 range. You may want to compare that to your truck and see if it is similar. There is a lot of friction between the gears, and perhaps one reason ford uses heavy weight synthetic from the factory.
Well I pulled the cover off - no fllings and oil was about a medium to dark brown. Everything looked OK . I ordered a '08 alum. finned diff cover and 4 qt of Royal Purple 75w145 gear oil. I'll try this first. Wish me luck.
I'd try and get ahold of an infared thermometer or something to check the temp so you know exactly how hot you are getting. Also could stick a thrmometer in the oil through the fill hole.
In industrial gearboxes I deal with the oil should not go much over 200 degrees F. I would think the same applies to the rear diff because it is just a gearbox. You definatly want to keep the heat down. It would be nice if you could somehow look at the bearing and see if it is discolored at all.