[clev]

I'm on a trip pulling a 12k trailer, 2k miles from home. I've detected a minor grinding sound from the rear end, but only when coasting or light throttle. When under load or heavy throttle, there is no sound. It's not getting any worse and the hubs are never overly hot. I'm concerned now because yesterday I discovered the right side rear tire is wearing down on the inside tread, the otter three are fine. What causes one rear tire to, all of a sudden, after 110k miles, start to wear unevenly?

 

[XRACER]

Wheel bearings.

 

[clev]

Thanks, X. Are bearings causing the grinding, the uneven tire wear, or both?

 

[Alaskapsdvan]

Any chance that it could be the differential?
Last month after months of a vibration slowing down or going down hill , found that the shims and bearing was a hair from going nuke...

 

[clev]

I cleaned the differential and replaced the oil with Royal Purple Synthetic last year. From what I could see, all looked good. That's all I know about it.

 

[Alaskapsdvan]

When the mechanic pulled the rear plug on the dif, he found not just a little but most likely all of the shims on the magnet....
So if you have a shop that you use for stuff like this I would get it in and have them go over it just make sure as to what is going on.

 

[clev]

I'm near Akron, OH and don't know anyone. About what can I expect to replace bearings and shims?

 

[XRACER]

I suppose that the diff could be the culprit, but grinding plus an untrue tire would lead me to the wheel bearings first. The mileage is about right for that too.

Do you have a full floating rear? If so, I believe that there are two bearings on each side.

 

[Alaskapsdvan]

If a wheel bearing is going and doing a number on the tire, what is it doing in the differential?

Just asking to learn more of what is going on.

 

[clev]

X, it's been so long since I checked the diff ID, I've forgotten. But I know it's a Limited Slip, ???Dana 60??????.

 

[XRACER]

Clev, the semi floating axle ends flush with the wheel, and the full floater has a bolted on cap that extends about 8 inches, allowing very easy access.

You could try jacking up that corner and shaking the wheel. Grab the tire at the top and give it a push and pull. If you feel or hear anything, you have a problem.

Alaska, a bad bearing shouldn't harm the diff.

 

[clev]

My hub extends about 6 inches so I have a full float. I do not have access to service manuals, but this appears to be a simple job. So, do I just remove the hub bolts, pull out the axle, replace the bearings, and reinsert the axle? Is it that simple?

 

[carringb]

My hub extends about 6 inches so I have a full float. I do not have access to service manuals, but this appears to be a simple job. So, do I just remove the hub bolts, pull out the axle, replace the bearings, and reinsert the axle? Is it that simple?

That's how you replace the inner bearings. But you have bad outer bearings. This requires pulling the hub. There is a special nut that retains the hub onto the spindle, that must come out after you pull the axle shafts. I watched by shop do it (replaced seals) and the steps were not complicated, but I remember they had to use some tools that I don't have in my basic tool kit.

If there is a lot of debris in there, you may want to go ahead and do the other side too, and clean and inner and outer bearings, as well as giving the differential a good cleaning.

BTW - I suspect you must have run low on gear oil in the diff. The bearings are really strong. I run at nearly 10,000 pounds on my rear axle, which should be the same as yours, and I have not had any problems, other than needed the seals replaced around 280k.

 

[clev]

Hi carringb; when I cleaned up the diff and replaced the oil last year, I filled it up until it ran out the fill hole. I haven't checked it since then but will check it tomorrow. Also, the Ford service dept replaced these same bearings in '06; 40 or 50k ago. I have sockets up to 1 1/4 inch; is the hub nut larger than that?

 

[blageurt]

The socket is 2 plus inches ....I have it it is a 3/4 drive deal and you will need a reducer to 1/2 inch I will go outside and check the size after I have a bite

 

[klhansen]

The best thing to do is pick up the specialty wheel bearing socket for your axle. It will have a pilot thru the center that goes into the axle housing where the axle was. They're typically 1/2" drive so you don't have to mess with an adapter.

If you feel looseness with the wheel off the ground, accompanied by the grinding you're hearing, I'd plan on replacing bearings and cups on that side, both inner and outer. Also replace the seal, and make sure you get the old seal off when you pull the hub. There have been a couple of guys who couldn't reseat the hub because part of the seal remained on the axle housing.

You need to pre-lube the bearings before installing the hub, and there's a procedure for properlly setting the bearing preload, typically torquing to a certain value while turning the wheel to seat the bearings, then backing off the nut slightly and retorquing to a lower value. You'll have to find the values. I couldn't track them down (my service CD is acting up).

Good luck.

 

[blageurt]

Ok my socket for my truck also a FF , is 2 and 9/16 " it says OTC 1928 on it as well and on mine you need a reducer from 3/4 to 1/2 inch ...good luck

 

[clev]

Good morning, blage and klhanson, thanks for the input. I just called the Ford garage in Abingdon, VA and they don't have sockets of any kind. Hopefully, NAPA will have what I need.

 

[XRACER]

I wouldn't drive too much further on it......

 

[clev]

I'm at my Dad's house and won't be driving. But. I'm going to have to let the Ford garage do the job. No one in town has the outer bearing.