Hi Folks!

First of all, I'd like to thank all of the experts in this forum for posting so much valuable information!!! I've learned so much and saved BIG $$$ by simply reading this forum and performing maintenance and repairs myself.

Now on to my problem... I had a "growl" develop in the rear end of my 2000 F250 4WD. The axle is the standard 10.5 Sterling with 230K miles. After reading this forum for hours and spending a few hours diagnosing and narrowing the problem to the carrier or pinion bearings, I decided that this was not a job I wanted to tackle on the cold floor of a garage. I took everybody's advice and took it to a reputable professional.

I had all of the bearings (Timken), races, and pinion seal replaced in the differential. I picked it up from the shop today and drove roughly 180 miles. When I got out and felt the differential for heat, I burned my hand when I put my hand around the pinion bearing area. The whole pinion area was too hot to touch... I don't think this is right.

I had 2000# of stone in my truck earlier this week and the pinion bearing area was barely warm when after 20 miles (at 60 mph) when I checked it.

Am I nuts or did my "reputable pro" tighten the pinion nut too tightly!?!!

Thanks for all of the input!!

 

did they break it in correctly?

 

if its that HOT i would think you maybe do have to much preload on that bearing...

call the shop and inform them before driving it anymore..

you dont wanna screw it up worse.

 

it's not normal at all to be that hot, it should feel warm when touched. Looks like you'd have to take it back to them again. Did you replace the crush sleeve? Ask them what was the torque for the pinion nut

 

I don't know if they "broke it in correctly"... I didn't know there was a procedure for that.

Yes, the crush sleeve was replaced (at least I assume it was as it was in the rebuild kit).

Should I question their procedure when I talk to them?

Does everybody else agree that it should only be "warm" to the touch and not hot??

 

1. There is no break in for it. 2. Its too hot. 3. Take it back.

It must be too tight and you can verify it by turning by hand, it should have a SLIGHT drag. I hope they put oil in it. Get back to us.

 

Update... I talked to the shop owner (the one who did the work) and he said that the bearing was "preloaded" to 12 in/lbs and that there is a short break in period for these. He said that each time I drove the truck the bearing would settle into the race and stop heating up.

I told him I would check it each time and if it continued to heat up I'd be back. He told me to drive it for a week and see what happens.

Thoughts!?

 

did you personally check and make sure it has gear oil in it? Should never be that hot, even brand new.

Did you check the shop references before hand?

 

Do you have a manual tranny and downshift a lot to decelerate?

That front pinion bearing is loaded more when decelerating and using a manual tranny to slow down, it'll get HOT.

But if it's under normal driving, or you have an automatic, well, no, it shouldn't be THAT hot.

I'd give it a week of driving and see what happens.

 

12 in-lbs is actually way below spec for a new bearing, that is in the range for a used bearing. New bearing preload spec is 20-35 in-lbs. When I did my gears I set the preload to about 32 in-lbs, pretty tight. I did several short trips to break it in, but unfortunately had to hit the highway and drive 330 miles back to school the next day. I took a laser temp sensor with me and checked it every so often and kept my speeds down to 55 max. On the highway I saw case temps as high as 180F around the pinion area and the rear cover was around 130F. I changed the original fluid out after about 800 miles and have had zero problems in over 12k miles so far. It is quite normal for them to get hot, over 120F is too hot to comfortably touch. As long as it doesn't get hot enough to break down the fluid you are fine, and change it out again after 500-1000 miles. I would question the shop on the 12 in-lb spec though, sounds like they set it up with generic specs and not proper for the 10.5.

 

I would check to see if they put oil in it, feel the pinon area again, and make sure you have a gaurantee. I've seen many (used) diffs with no drag on the pinion, many with some drag on the pinion, and some with lots of drag on the pinion and they all were in good condition. Jack it up and spin it to see if there is massive drag on the pinion.

 

They obviously put oil in it, he drove it 180 miles. It wouldn't last 5 miles without gear lube. Its pretty normal for them to get hot at first, that is why you should change the fluid after 500-1000 miles.

 

I was thinking like maybe not enough oil. Of course you would know it if there was no oil in it. Let us know what it was. (I am assuming it is so hot you can't touch it).