About a year ago, I purchased a 98 F150 4X4 4.6L with a 3.55 Limited slip differential.

I may have more than one problem, but I will describe the issues I am having and would appreciate any feedback. This may be a little long, and I apologize.

The first snow storm of last year, we had less than an inch of snow, and going over 20 mph, the back and felt like it wanted to spin out. It would move left and right like one wheel would catch solid ground, and then the other would catch moving the back end of the truck back and forth.

I replaced all 4 tires with brand new tires, and the problem still was there, but not as noticeable. Since putting the new tires on in January, I have put 10,000 miles on the truck, and the front tires are in great shape, where the back tires are to the point that I have to replace them before winter.

When driving in rain I have the same back and forth feeling from the back end as when I drive in snow.

The outside edge of the right rear tire is warn like a front tire would be if the tire is not aligned properly and the inside edge is wearing. The rest of the right tire, and the left rear tire is warn to about 20% of the tread.

From driving the truck, I notice three things.
1. In motion, it seems like the rear end of the truck is louder than other F150's I have driven in with same tires,etc.. There seems to be more of a constant rumble type noise from the rear.
2. When Stopping, sometime the back end seems to want to move to the right. (My thought was is the bearing going on the right side?)
3. Sometimes when going around sweeping left turns at 20MPH+ the back end seems to want to move to the right, like if I was going to spin the rear end out.

My thoughts are wheel bearings, the limited slip is not slipping when it should. Any ideas are appreciated. Also what type of repair shop would be best for rear axle/differential type work?

Thanks, and sorry this is so long.

Chuck

 

[updated:LAST EDITED ON 04-Oct-02 AT 02:47 PM (EST)]The limited slip has a clutch and gears that can wear out or go bad that would be my guess. If you replace your differential don't get the OEM one get a good after market one Auburn Gear makes a good replacement.

http://www.auburngear.com/

 

Thanks for the input. What is the ball park price to have have this type of work done? If I am replacing the differential, is there any other parts that I might want to replace while this work is being done?

With my right rear tire wearing on the outside edge, could that side bearing be causing this?

Thanks again.

 

The constant rumble sounds like a bearing is going. At some point it should start leaking oil out around the brake assembly. A bearing that shells out, puts a lot of metal into the system and often the little pieces bury themselves in the clutch packs. Your differential is probably fine, but you may need to replace the clutch packs since it is nearly impossible to get the little metal parts out.

Not sure about price. Mine were replaced under warrenty.

 

check my avatar, this is what happened to my 97 F150

 

Phayzed, your pictures scare me.
I havn't seen any oil yet.
Ultramagden, Do you mean the outside wheel bearings, or the bearings in the Differential case? I was thinking the outside bearing whould be the reason my right rear is wearing on the outside edge.

Thanks for the input.

Chuck

 

[updated:LAST EDITED ON 06-Oct-02 AT 08:26 PM (EST)]The outside wheel bearing is the one most likely to fail.

When mine was going out you could hear a low rumble (or odd sound) driving down the highway. The longer I went, the louder it got. One night after towing a chevy home I noticed a bunch of oil on the ground by the rear wheel. I pulled the axle that night and the bearing was toast. You could move the axle while it was still held by the e clip. I wasn't far from losing the axle out like others have done.

Your rear tire wear does sound a bit odd though. A bearing that badly out of specs is going to make a bunch of noise and should be leaking oil all over the wheel.