Odd Shutter 2000 F150

I have a shutter that seems to be coming from the rear of the truck. It can be felt in the seats. The shutter only lasts a few seconds and is much more noticable when turning from a stop while pulling a tandom wheel trailer.

Do you mean a shudder ?

Does your truck have a limited slip diff ?

" limited slip diff " ?

Do you mean a posi track rear axle ?

From what sprayman has said I would be looking at the rear suspension components. The spring mounts are prone to cracking and that could be the cause of the shudder.

Yeah, I was refering to a posi rear end.

I would agree with the suspension check, is the shuddering acompanied by any noises, like creaking or squeaking sounds ?

We need some more information from sprayman, how about it ?

Before you tear anything apart, purchace a bottle of rear end friction modifier and install in the truck. Make about 10 full tight circles to the right, and about 10 full tight circles to the left and see if it helps any. The clutches on the side are subject to slippage and the modifier restores the friction.

wat2old has got it right, you have to get the additive from ford it should take care of it.