bumpsteer

[73 Bronco Sam]

Hello all,

I am having a bumpsteer issue. I have had the box rebuilt and have a 4" drop pitman arm. The steering is smooth but it is a little scary driving. I have read numerous blogs on bumpsteer but need help. I am in SoCal, any help would be great.

Sam

 

[73azbronco]

everything stock? Lift kit?

 

[broncnaz]

Do you have a drop trac bar bracket? even with one sometimes its not the correct drop in relationship to the drop pitman arm and can cause bumpsteer. fixes are to get a adjustable trac bar and drag link. But you also need to make sure your alignment is good and that the trac bar bushing are good along with the tie rod ends all can contribute to bumpsteer.

 

[73 Bronco Sam]

Fiberglass body, 351w, duel Bilstein shocks all around, new 36-15:50-15, 5 1/2 lift, 4" drop pitman

 

[73 Bronco Sam]

Should the trac bar angle and the drag link angle match perfectly and mirror each other?

 

[braxton357]

They should be parallel. Are you getting bumpsteer or death wobble? The terms get mixed up a lot..

 

[DonsBolt]

Yo Sam

I am not saying you don't have a bumpsteer issue, as indeed you might. However I would check your toe in. Sometimes to much toe in can make it feel like a bumpsteer issue.

Tale some masking tape, run it on the backside of one tire to the other. Then roll the truck back so the tape is now 180 degrees oposite of where it was before, now on the frontside of the tire. Then take a pair of sissors, and cut the tape in half.

If you have over 1/8th of a inch thats to much toe in. If so turn the tie rod adjusters out a little till you get it where it should be. You will have to redo the procedure a few times to get it right.

I run 1/16th of a inch on mine.

Also what degree C bushings are you running???

 

[73 Bronco Sam]

The wheel does not shake at all, the truck drifts. If I hit a bump I have to white knuckle it.

 

[73 Bronco Sam]

I will try the tape thing.

 

[Goin Off Bronco]

your drag and trac are off. post a pic of them for us.

 

[70_Steve]

They should be parallel.

Not necessarily. Parallel only if the track bar and drag link are the same length, which is rare. Take a look at this link that does a pretty good job of explaining our steering setup, and bumpsteer.
http://bulletproofsteering.com/geometry.html

 

[Fast Pat]

Mine was doing the same thing especially on off-camber roads. It turned out that tracking was off (rear not following the front). I had to install an adjustable tracking bar to move my front-end over about 2" and it was cured.