Bumpsteer on properly setup steering

BuildBreakRepeat

BuildBreakRepeat

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Evening all, I am currently running a Currie trackbar and Currie steering. My axle is centered using the gun-sight method and the steering is aligned to 1/8” toe-in, and wheel is straight. When going over bumps slowly I experience steering wheel movement that cycles from the 10-2 position on the steering wheel. Is there a specific reason this is occurring? Or is this just a characteristic of a straight front axle and our Jeep’s geometry?
 
BuildBreakRepeat said:
Evening all, I am currently running a Currie trackbar and Currie steering. My axle is centered using the gun-sight method and the steering is aligned to 1/8” toe-in, and wheel is straight. When going over bumps slowly I experience steering wheel movement that cycles from the 10-2 position on the steering wheel. Is there a specific reason this is occurring? Or is this just a characteristic of a straight front axle and our Jeep’s geometry?
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Pitman has the incorrect amount of drop.
 
Mine doesn't do this. The steering wheel has very little movement during a bump.
 
If you hit a bump , and the wheel moves, this tells you the axle is moving left to right , rather than staying centered by the track bar.

Notice the drag link is connected to the pitman arm ..that is what is transferring the movement to the wheel from the yoke it's attached to on the passenger side .

Now look at your track bar angle and your drag link angle , if possible, photo and post..they need to be parallel as possible .

All I'm doing is describing the realm where I think this is starting , to see if we can dial you in.

Be sure the pitman arm is stock...it's a dead ringer for bumpsteer .

Also have a friend roll it slow and slam the brakes and see what the control arms are doing ...excess axle movement can pull the linkage .

Let us know what you see.
 
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AndyG said:
If you hit a bump , and the wheel moves, this tells you the axle is moving left to right , rather than staying centered by the track bar.

Notice the drag link is connected to the pitman arm ..that is what is transferring the movement to the wheel from the yoke it's attached to on the passenger side .

Now look at your track bar angle and your drag link angle , if possible, photo and post..they need to be parallel as possible .

All I'm doing is describing the realm where I think this is starting , to see if we can dial you in.

Be sure the pitman arm is stock...it's a dead ringer for bumpsteer .

Also have a friend roll it slow and slam the brakes and see what the control arms are doing ...excess axle movement can pull the linkage .

Let us know what you see.
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All stock locations for the steering and trackbar. I’m going to ensure all my control arms are the correct alignment and length. That’s the only other thing I can think of. Unless @mrblaine is correct and somehow the stock pitman arm is the wrong amount of drop for the stock setup.
 
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I doubt anyone knows more on steering out here than @mrblaine , and he has probably about seen everything . If someone raised a track bar frame mount that would be similar , and control arm movement would need considered .

You will get it resolved . Keep at it.
 
AndyG said:
I doubt anyone knows more on steering out here than @mrblaine , and he has probably about seen everything . If someone raised a track bar frame mount that would be similar , and control arm movement would need considered .

You will get it resolved . Keep at it.
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From what I’m seeing it has to be control arms or alignment.
 
BuildBreakRepeat said:
That’s unfortunate. I always figured the stock pitman arm would be the right drop. I’ll get out the string and angle finder to see what amount I’ll need.
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They aren't as parallel as they could be from the factory. The draglink is longer and they fixed that by changing the angles between them slightly to compensate. Sort out your other stuff first and then take a look at the pitman with an eye towards adding or taking away drop to solve the slight bump steer issue.

It isn't common but I have seen it a few times.
 
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mrblaine said:
They aren't as parallel as they could be from the factory. The draglink is longer and they fixed that by changing the angles between them slightly to compensate. Sort out your other stuff first and then take a look at the pitman with an eye towards adding or taking away drop to solve the slight bump steer issue.

It isn't common but I have seen it a few times.
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Thank you, I will spend some more time on it today.
 
No one was free today to drive while I watched the suspension, but I rechecked the alignment (still 1/8” toe, axle aligned from left to right) and the problem persists. Obviously there are compromises with the stock setup given that the drag link and track bar are unequal lengths. The angle is slightly off, and this could be fixed with a different pitman arm. I’ll probably just drive it as is for now given that there isn’t a quick solution.
 
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