I have a 2001 F-150 Supercrew 4X4 with 115,00 miles on it. About 20,000 miles ago, it began to shudder slightly as I would begin to accelerate and turn either right or left from a standing stop. It has gotten progressively worse since. It doesn't shudder when I'm going straight forward from a standing stop, just when I'm making a left or right turn, and then once I straighten out, it stops shuddering.

Any ideas?-someone said it might be a front differential issue.

 

I have heard someone say(or read it during my search for answers) that their car was doing the same thing and changed the differential fluid which seemed to fix the problem...... They said the old fluid smelt like rotten eggs....

 

Sounds like your front hubs are locked in and your in 4x4.

 

Do you have a limited slip rear diff? If so does it have clutch packs? I know for sure this issue happens alot on the 2003 and up models although I have not experienced it with a higher mileage 01 -02 model. The limites slip diff has a series of clutch packs in it on the axel gear in the spider set. remove the 5/16 bolt slide out the pin, remove the c clips that hold in the axles and slide out of the way, with a pair of channel locks grab the large S Style spring and pull this out. Spin the spider gears around and remove the gears, pull the clutches out paying close attention to the clutch shim spacing. Reverse the procedure for installation. Oh yea using a bench vise compress one side of the S spring wrap it with LARGE Zip ties and pull tight, the zip ties willbe cut as you tap the spring back into place once in remove the ties with pliers. Be sure you soak the clutched in XL-3 and gear oil for atleast 1/2 Hour.


Hope this Helps

 

ok just rebuilt one today the s spring is not in this model it has a cone style spring in the spider gear you have to remove the center section and spread the axle gear and remove the spider gears. then you replace turn the gears(note Special tool ford only) although you can use a piece of all thread and some washers and 2 nuts and spread the axle gears then tap the axel gear around to remove the spider gear. then you have to replace the clutches and respread the gears, put 3 zip ties on each spider gear to hold the bearings in place and reverse procedure. If you are not familiar with diffs i would highley suggest letting you dealer replace the clutch packs. labor is about 7 hrs.