My work has a I belive a 2006 F650 with the Cummins Motor and the Allison Auto Trany. It has had since day one a rough ride and this bucking vibration. I have reported it several times and they only thing that the dealer found was supossed bent rim. It is so severe that it gives you a headache from the jarring motion. Is there anyone that has experinced this please give your input. Is this normal?

 

Its a heavy truck.. The ride isnt going to be nice.

What suspension does it have?

Jack up the rear and check the pins on the rear leafs, if it has leaf suspension.

I've seen trucks "buck" under a load at certain rpms because the rears will start to twist up and down because of looseness in the suspension. All the trucks I've seen bucking have been tandems with hedrickson beam suspension.

It makes the ride a little more interesting..


If you want to see your truck buck.. Go north up I5 between Seattle and Tacoma in Washington.. Or north up 405 in Bellevue Washington.