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Discussion Starter #1
ok this is for a RMW 92.
Every piece of front sterring was renewed or replaced. steering gear new from Delphi.
new B46-1516/1517 shocks
17" Impala SS rims installed.
geometry set.

on flat road it is quite good for what it is (old design car)

on less flat roads I have noticeable bump steering.

I was thinking of putting new MOOG variable springs and may be sport B46-1104/0929 Bilstein shocks to limit the suspension travel and possibly limit the bump steering.

But yet I think it could be something else I have to do ??

Any idea ?
thx :)
 

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If you installed the parts correctly, had it aligned correctly, and you did not have bump steer, you should not have it now.

Bump steer is caused by the misalignment of the pivot points of the inner tie rod mount/center link joint. If they are not aligned with the extended line through the center of the lower arm pivot(s) you get bump steer. There is a link made that allows you to adjust the up and down position of the pivots to align them with the centerline of the arm pivots. The distance between the mounts for the inner tierod ends is too wide or narrow, it will also cause bump steer. Unless you got the incorrect center link, the mounting points are not adjustable.

If you got an incorrect idler arm for the passenger's side, it could raise or lower the pivot for that side. The steering box side is less likely to be out of position, because the Pittman arm is not changed, or moved. If you changed the Pittman arm, it could be one of the possible issues.
 

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Not sure how you could possibly have a bump steer problems with stock steering unless something is bent or you got the wrong size parts. Perhaps you're problem is with the wider Impala tire riding the groove and or the crown in the road.
 

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If you're referring to the car wanting to go this way or that way as it hit irregularities in the road, i found my 95 did that when i put on the impala ss wheels. Same thing corrected other cars i have that act like that. Always turned out to be toe setting needed to be readjusted. 1/16 - 1/8" toe in and all is good again.
The original tires with their taller softer sidewalls tolerate it being off much more. Got to a lower profile tire and whammo, car becomes almost undriveable. I adjust myself and it works out great.
 

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Discussion Starter #5
OK.
I think that the Impala Rims are not helping but I tried several geometry settings toe in to 0° or toe in a little bit.
Less caster (from 4.5° to 3.5°)
The wandering attitude still there on not perfect flat roads.

I think that may be the rod pivots are not where they should be (assymetrical probably) Did I say my steering wheel does not point straight ?

However except the normal setting with the tie rod end adjusting sleeve I do not see what else can be adjusted ??
Pitman arm is OEM but steering gear is new Delphi 600 (if I remember the ref)
Idler arm is moog problem solver. cannot adjust position I think.

All in all if someone has the detail of what to look at and what to measure I take it !!
 

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If the steering wheel is not centered, the steering center link will be offset. This could be the source of your bump steer. Center the steering wheel, and then check for bump steer.
 

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There is an aftermarket "race" drag link for these cars that has provisions for adjusting bump steer. I have one on my Impala.
 

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I can't see the large image on Howe's site for some reason... What kind of adjustment range does that center link give you?
 

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The adjustable parts are the ends of the link that attach to the Pitman arm, and the idler arm. You can raise or lower the link in relation to the plane of the lower suspension arm pivots. The optimum position is to place the inner tierod joints in the same plane as the suspension arm pivots.
 

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I reread the thread, and the Pitman arm may be installed on the steering gear in a different position from the original. If it is not as far on the shaft of the steering box, or conversely too far on the shaft, it could change the installed height of the tireod end links relative to the plane of the suspension arm pivots. This would be more on the driver's side than on the passenger's side. You still have to center the steering wheel before checking the center link installed height.
 
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