[sebastian dipietro]

a fiend has a 57 chevy truck. we replaced the front leave springs with a lowing set designed for the truck. a new set of rims and tires 195/55/15's. the problem we have is what one person said was washboarding the front moves from side to side during driving to the point of being scarry . it seams to happen only on the right side.
there is a power steering unit on the left side that connects to the spindle and a tie rod to the right side. we have installed a panhard rod and that has not helped. installed heavy duty shocks that help a little. when it shifts the steering wheel does not move but the whole truck moves about. anybody have this problem and can give some advice on what to do to correct the problem. there is no sway bar on the truck . tia luke

 

[LeoP]

did you torque the u bolts to the proper spec????

 

[496blaze]

How bad was the caster affected when the truck was lowered? If the caster was reduced it will cause it to be more twitchy when driving.

 

[twotone64]

How bad was the caster affected when the truck was lowered? If the caster was reduced it will cause it to be more twitchy when driving.

Has a front axle not independent front end, UNLESS they changed it. But by stating they had added a Panhard Bar gave it away that it wasn't independent.

I would check to make sure that your front axle is perpendicular to the frame, and parallel to the rear axle. ALSO pick up the front end by the frame, and see what kind of movement side to side, and front to back. Make sure the king pins aren't wore out as well as the bearings on the spindles. Basically look for any and all movement. Were the bolts tight moving through the leaf spring bushings. If they were loos you are going to get movement there.

 

[shomejim]

Did you replace the shackle bushings? You can get some play from worn out ones. You just said you replaced the leaf springs.

 

[shomejim]

Also , I forgot to mention , on your power steering gear may need adjusted. My truck tended to wander after I put late model PS on it. After I adjusted the box it took most of the wanderlust away. New bushings in the shackles did the rest.

 

[sebastian dipietro]

thanks everyone for the replies. the front was replaced with a new disc brake conversion when we replaced the springs. all bolts were torked to specs. the front was alined after all work was done and the steering was centered. the problem seams to show its self when two roads come together like a main street with a side street coming into it to form a tee. were there is a dip going into it . the truck actually seams to push itself like it is twisting the frame to overcome the roadway any other thoughts luke

 

[twotone64]

When the disc brake setup was done, did you just put brackets on the original spindles and new rotors, or did you replace the entire spindle assembly? If you did replace the entire assembly, let me know about it, I wanna do the same to my 55. ANYWAY if it was just a bracket and rotor swap the kingpins (pivots for spindles) can still be worn out even if they were tightened to specs. The front end alignment can still be done. I would go ahead and get the front end off the ground and check the things that everyone has mentioned. Also you have let us know if you replaced the frame bracket bushings. The new springs probably came with new ones for them, but maybe not.

 

[Tom Mobley]

IMO you need to get that thing into a decent shop for a close inspection of the previous done work and the alignment.

caster is increased by using wedge shims between the axle and the springs.

 

[sebastian dipietro]

Two tone the disc brake was a kit complete with booster. every thing was a bolt on very easy to do. back to the problem the kingpins seamed tight and if not should the alinement shop should have caught any problem with them? The springs were all new with all new hardware new bolts throughout. Luke

 

[sebastian dipietro]

Tom the shop is a very good shop one of the best in the area they are known for colinsion repair on high end cars. Most of the car shops go to them. Luke

 

[Tom Mobley]

they might do fancy collision repair but that doesn't mean their front end guy knows anything about kingpins.

jack up the front end under the axle and work the tires in and out at the top and bottom.

the pins that go through the bushings on the leaf springs are tapered on the ends. the shackles have tapered holes to match. make sure this stuff is installed correctly.

last time I fixed one of these trucks they had installed the new king pins but left the old completely worn out bushings in the spindles. When asked why they said nobody asked them to replace the bushings??? duhhhhh.

There's a thrust washer setup on each side, it goes between the bottom of the axle and the top of the lower bushing bore. I've seen these left out completely by "techs" that were experts......on MacPherson struts.

Is there a local truck shop that does front end and alignment work on solid axle trucks?

 

[LeoP]

If you can't find anyone to help, I'll be in Va Beach the last week in Oct. Let me know. I'll PM you when we are gonna be there. good luck.

 

[driveshaft-texas]

If "washboarding" is really a wobble...it is allowed by slack somewhere in the ft end. A steering stabilizer will help if its just a little wear in all the components, including the steering box. A road bump can set it off around 35-40 mph up and a tap on the brakes can dampen it but usually the only solution is slow down. Worn and/or out-of -balance tires will affect this , but you stated they are new.Caster near 4* + will help if the steering is touchy and might help contain the wobble .
Go back to the alignment shop and tell them your problem.

 

[Jim Mac]

Google death wobble. 4x4 with solid axles get this issue and theres probabaly some help there.

 

[Jim Mac]

See if you can borrow a pair of front wheels and tires off another car and try them out to see if it reduces or chages it