First of all hello and thanks for this site, I've had other problems resolved here without posting but can't find the answer to this one.

I have a '98 f-250 with 95,000 miles and when turning after a dead stop there is an extreme noise and vibration which feels like gears or a wheel bearing rubbing which goes away as soon as the front wheels are straightened out.

I've had it off the ground and looked in the differential and shook the wheels but i can't find the problem or any excessive play.

Any help would be greatly appreciated.
thanx
Mike

 

Welcome to FTE prohopwer.

Does your truck have a limited slip differential? If so, it is time to change the differential gear oil and to add a 4 oz. bottle of friction modifier.

 

yes it does, I recently changed the gear oil $60, I'll try some friction modifier, thanx

 

Souunds like a bad in board or out board CV joint.

 

if the friction modifier doesn't work I'll check more into the cv joints, I only spotted u-joints under there and there is no noise when starting out in a straight line no matter how much gas I give it. I had a bad cv joint on my bronco II and the noise is very similar except I didn't have to be turning and barely moving.
thanx Deebo

 

you can get a 7 ounce tube of frictin modifier at Auto Zone for $5. that will fix it.

 

This is very common with the limited slip rear diffs, especially when warmed up. This is caused by the clutch packs for the limited slip being shimmed too tight and when turning the spider gears would turn very tight giving the shudder. Some guys had them fixed under warranty, but usually an oil change and friction modifier would cure it -- for a while anyway. Make sure you use a good synthetic oil, that is what Ford recommends and is in the newer trucks from factory.

 

clutch packs could be shot, mine were

 

Try the friction modifier. If that doesn't work, you'll probably need to replace your differential clutch packs

 

I'm just waiting for the friction modifier to arrive, I bought it from a Ford dealer on the 9th on E-bay so it should be here soon.

I'll let you know what happens and thanks for all the replies.

 

Just started doing the same thing a few weeks back. I was suspecting the diff clutches. any update on this?

 

mcanik have you tried changing the oil and adding friction modifier?
If that doesn't fix it Snow Valley should have, and Totem usually has, clutches in stock.

 

Will do Racer guy. Gimmee a few days. I will get back to ya with the results.

 

There is/was a TSB on this and they would change the clutch packs. Naturally you have to be under warranty.... Find and read the TSB for more info.

 

My 2003 SCrew FX4 (5.4/3:73 gears/limited slip diff) with 72700 miles on it did the same thing last week...had the shudder/vibration during shallow turns (1/2 to 1 turn of the steering wheel) at low speed and upon acceleration. After a 26 mile drive home, rear end was "howling."

Dropped it off at the dealer, they replaced the "Gear and Pinion and Diff Clutch Packs per TSB 05-23-30."

The repair was covered under my Extended Warranty so I can't tell you how much it cost to fix...they had my truck for two full days. I'm guessing $800 - $1000. Am I close?