Freightliner - serious front-end vibration

Did you just have front tires mounted? Are they installed out of round? Look at the bead and see if it is uniform.

I had a Volvo one time that had tires mounted incorrectly, and had to have them both redone to stop the vibration, but it was not violent.

If they are not wheel centering pilot hubs, one can put a dial indicator on the front tire and loosen lug nuts and usually get enough movement on lugs to adjust out of round condition. Put high spot up top and let wheel drop when loosening; repeat.

Do you have a busted cord on a tire....

A broken spring shakel? Kenworth one time broke a shakel coming up to a light not going more than 20 mph....

 

Had that with my 06. First thing replaced shocks. Took care of it for awhile then came back. Ended up replacing Kingpins. So far so good.

 

Stone Express said it all!

 

The shocks remove one end and see if they have a dead spot, if not take it for a drive for 15 minutes if they are hot they are good if cold they are junk.
Check the wheel bearings, the hub cap has a plug in it remove it and look for metal.
As suggested spin the tires and look for a bent rim a bulging tire or out of round also put the tire in different positions some will never balance, .090 out of round many times can be repaired by repositioning the tire on the rim.
Inspect the brake drums for a missing weight.
King pins are a possibility as posted.
I have had units that we found the wheel hopping by driving and have anouther vehicle drive beside it and the passenger looking at it.
Check the tie rod ends, and drag link just twist the steering linkage by hand, back and forth. Put your finger on it and feel for play.
The rear spring pin links if there is play you can buy shims to tighten them up I remove the hanger from the frame and use a clamp to get them as tight as posible, then remount the hanger.

 

Don't just look up front, check you rear suspension as well. Amazing what a couple loose or stretched ubolts on a drive axle will do.

 

I just had my king pins replaced with three axel alignment and i replaced the Shocks. Vibration went away.

 

Rule of thumb. below 45 mph - out of round, 45 to 55mph toe, over 55mph balance( drum and hubs included). The faster the truck rolls the more toe-out force is exerted on the steer tires. If there are worn components on the steer axle, such as a small amount of wear in the tie rod ends, loose wheel bearings or king pins, the set toe can easily change well over an 1/8". Remember when we were kids and you would hold a bicycle wheel by the axle and spin the wheel, there was a force moving it side to side. This same force exists in steer tires and will work against each other with a small amount of toe-out. I have found this is an issue often over looked by alignment techs. I check tie rod ends with a large pair of channel lock pliers, for any vertical movement( should not be over 1/16"). There is not one set toe for all vehicles. Long haul truck 1/16", with a small amount of wear in steer components, 3/32". P&D and dump trucks, as much as 1/8". Another over looked item are the shocks. The purpose of a shock is to keep the tires on the ground. The easiest way to check is to buy a temp gun and after coming off a long stretch of hi-way, check the lower portion of the tube. They will be warm to hot and should be the same temp side to side. This is also a great tool for checking wheel bearings and tire pressure. A tire that's hotter than the rest will probably be low air pressure. Hope this helps.

 

I know this is an old thread but had the same exact problem on a 01 FLD i just bought, steer tires looked brand new, had them balanced and same problem. Went to a spring shop and they jacked up the front end and used an old school machine that spun the tires at highway speed and those tire were shaking and vibrating like crazy, changed the tires and went away. Now ive got a couple useless tires, theyll go on a trailer when I dump it. Also we put in a few lugnuts for stud pilot hubs, one was worn just a little bit and figured this would be ok until i replkace the hub in the future...........