I've got a 03 f150 shortbed regular cab with 3.55 gear limited slip rear that ocassionally when i turn left or right and start to go there is a chatter/vibration come from the rear. I have checked everything I can think of ujoints, ubolts, shocks, mounts etc. is this normal? Seems like the diff is trying to lock up.Preciate any info

I've got a 03 f150 shortbed regular cab with 3.55 gear limited slip rear that ocassionally when i turn left or right and start to go there is a chatter/vibration come from the rear. I have checked everything I can think of ujoints, ubolts, shocks, mounts etc. is this normal? Seems like the diff is trying to lock up.Preciate any info


Your truck should have the Torsen differntial. It uses helical cut gears instead of springs and clutchpacks to distribute power evenly. If it is shot, I don't think it could be rebuilt without exceeding the cost of a proven aftermarket LSD. Do you have a drivetrain warranty?

This is very common on Fords. I actually have an Explorer in my stall this very minute with the same problem. It's the clutches in the limited slip chattering. You can try adding a bottle of friction modifier through the rear speed sensor hole on the top of the diff and then driving in a bunch of forward and reverse figure 8s. That sometimes fixes it, otherwise there should be updated clutches for it.

I added a bottle of the friction modifier thruogh the fill hole but i didnt do the figure 8 thing as far as the warranty not sure I only have 40000 on it so it is passed the 36 bumper to bumper preciate the info, will it hurt to continue to drive seems to do fine goin straight

I don't think it will hurt anything if you leave it. And unless you have ESP or some aftermarket warrenty it won't be covered anymore.

This is very common on Fords. I actually have an Explorer in my stall this very minute with the same problem. It's the clutches in the limited slip chattering. You can try adding a bottle of friction modifier through the rear speed sensor hole on the top of the diff and then driving in a bunch of forward and reverse figure 8s. That sometimes fixes it, otherwise there should be updated clutches for it.


A Torsen differential has no clutches, it is entirely mechanical.

A Torsen differential has no clutches, it is entirely mechanical.

It's not a Torsen Diff.

I've got a 03 f150 shortbed regular cab with 3.55 gear limited slip rear that ocassionally when i turn left or right and start to go there is a chatter/vibration come from the rear. I have checked everything I can think of ujoints, ubolts, shocks, mounts etc. is this normal? Seems like the diff is trying to lock up.Preciate any info
Take it to a dealer that is a normal problem. We have fixed alot of these at work there is a updated clutch pack coming out some time the only way to get them now is to replace the carrier assmbly

what kind of price should i expect on that and should I plan on haveing to do it again at 80000?:( :barf: :(

sounds like my dead traclok.
if it is a clutch pack unit rebuild it and get used to doing it fairly often as every time you turn you are burning clutch lining.
I think the chattering starts when it finally goes metal on metal.