steering problems

[gonefishin9335]

I have a 73 bronco with a 3.5 lift. i have replaced everything on the front end i know to replace. Rebuilt gear box, tie-rod ends, ball joints, drag link, bushings, trac bar, shocks, coils, and drop radius brackets. The problem i'm having is the bronco darts to the right when I let off of the gas pedal. It only does this at speeds above 50 mph. I don't know what else to check, replace, or try.

 

[Broncobowsher]

I will guess a mild case of bumpsteer or maybe different rear tire diameters(wear)/materials (different tires) with a rear locker.

If I drive it in person I can tell a little better.

 

[cbearly]

Do you have a locker in the rear? I think that is pretty common to have it pull a little bit when you suddenly let off the gas if you are running a rear locker.

 

[77bronko]

Maybe check your rear end. Bushings or springs. My does the same thing and that is the next thing I'm going to try and replace. Mine goes one way when accelerating the other when I let off the gas. And I don't have a locker.

 

[spixican07]

You know mine does the exact same thing. I was kind of thinking its due to not having a dropped pitman arm, body rolls forward and drag link pushes the car to the right. Like the opposite of bump steer.

After reading what you've said I'm not so sure...I was thinking about replacing my tie rod and drag link to try to fix it but if that won't then I don't know what to do.

Maybe its a camber issue?

 

[broncnaz]

other than a locker causing the problem. It still could be a track bar/drag link issue. You may need a adjustable tac bar and drag link. Most suspensions are fairly generic ie track bar bracket and drop pitman arm are usually the same for 3.5 and 5.5 in lifts so they are probably just a good in between. A adjustable trac bar and drag link will get your lenghts correct and should fix any bump steer problems.

 

[Broncobowsher]

If it was camber it would pull all the time. Something is shifting when you let off the gas. It become apparent when you do it over 50.

Just a thought, Put her in first and punch it and wind it out. At the top of first, snap off the throttle and let it engine brake, don't shift into 2nd. Does it dart then? That should put more movment into the suspension then doing it at 50. If it doesn't, then I am really stumped. If it does, is it any worse then at 50? It might be easier to feel if it is coming from the front or the back that way as well. I still lean toward a mild case of bumpsteer, but can't say for sure.

 

[gonefishin9335]

i've taken to a buddies of mine shop this morning to check the front end out and whatever else he may find. i have adjustable trac bar and drag link already installed.

 

[gonefishin9335]

my buddy couldn't find anything wrong with the front end or anything else. He believes that it's a locker rear-end.

 

[Broncobowsher]

my buddy couldn't find anything wrong with the front end or anything else. He believes that it's a locker rear-end.

Swap the left and right rear tires (even if they are directional, but them on backwards).
Go for a drive. If it is the rear end it should now pull to the other direction.

 

[spixican07]

You can easily find out if you have an open differential or not by jacking up your rear end and spinning a tire. If they spin the same way, there's a locker there (or some sort of locking-similar diff). If they spin opposite directions its open.

I'll try the first gear thing, but based on driving experience I expect that it would make it worse. My dad was driving it and had it in 2nd by mistake, got it up to 50 and let off, and that was definitely worse than when it was in 3rd.

What does that tell you?

 

[rednck21]

my buddy couldn't find anything wrong with the front end or anything else. He believes that it's a locker rear-end.

can you post a pic of your tie rod/drag link? im thinkin bump steer...

spixican07...this goes for you too!

or send them to me and ill post them.. rednck21@msn.com

 

[spixican07]

Here's mine.

They look decently parallel to me, but I don't know much about suspensions.

 

[rednck21]

they are parallel, but they are also at a pretty steep angle which i think might have something to do with it.

 

[Broncobowsher]

they are parallel, but they are also at a pretty steep angle which i think might have something to do with it.

I was noticing that as well. When mine were like that I would get a funny Yaw when going through dips in the raod (front suspension cycling at speed). Also did it some, but not as bad with throttle and brake inputs.

 

[rednck21]

for reference, heres my setup. adj. trac bar with a 3" tb drop and a drilled stock pitman arm. ive got zero bump steer im only running a 3.5" lift though. it does dart under hard braking/acceleration, but only VERY slightly. its a bronco, not a caddy...

 

[68ford]

if it darts to the right when braking and goes to the left during acceleration, its the geometry of the radius arms. the radius arms both point outward, this makes the axle only straight or perpendicular to the frame rails at on exact point. having steep angles makes it more noticeable due to more side to side movement. picture your suspension as if you were looking down on your rig looking through the hood, youll see that as the axle moves to one side or another the axle actually turns, because one radius arm becomes more straight and the other more angled.

ther is nothing you can do about this except build radius arms that are parallel with the frame rails.
this is similar to what people refer to as lean steer with a 4link.

 

[4x4man514]

when mine was doing it it was a simple fix. i too have a locker. what it turned out to me was tire pressure. i felt like a real dummy when i discovered it. a slacker tire is shorter, or smaller. i knew in theory it would do that but i didnt think it was enough to make a difference. it did. you have probably already checked that but i thought id let you know in case you havent. i think it could be easily overlooked. i did.

 

[gonefishin9335]

do i need more or less tire pressure.

 

[Broncobowsher]

do i need more or less tire pressure.

even tire pressures side to side.