Bump steer

[nicbeer]

I have heard the name going around and also similar names.

What is it and how do ya notice it.

I have read in lifted vehicles, it is more noticeable?

cheers

[christover1]

I have heard the name going around and also similar names.

What is it and how do ya notice it.

I have read in lifted vehicles, it is more noticeable?

cheers

on some cars the axles/diffs move forward or rearward with suspension movement..when only one wheel gets compressed/drooped, the car can skew..ie hit a bump and it tries to turn a little....especially noticeable when you add more travel, or more offset on wheels...a tech head may give better description..christover

[droopypete]

when the tie rod and the drag link are parallel you do not have any B/S,
when you lift a zook, (that is move the chassis away from the diff)
the angle of the drag link is increased (in relation to the tie rod)
any compession of the suspension will result in B/S
to make it simpler, if you were to lift it up to a point where the drag link was at a 45 degree angle to the tie rod (see love_mud ) a downward movement of 20mm would translate to a 20mm move in the swivel housing (assuming to front comes down the same amount on both sides)

SPOA is the worst ofender, but this can be solved by a hi steer conversion.

When you are driving down the road and the car hits a hole or similar the front suspension dips and you get B/S.
peter.

[DeWsE]

I'm no tech head, but I am a webwheeler

You are on the way to your favorite trail. You hit a pothole. The steering wheel is jerked violently left then right as the truck is heading to the side of the road. You have bump-steer!

This phenomenon is a result of modifying your tie rod and drag link geometry. The tie rod and drag link, as installed at the factory, are very close to parallel. Keeping these components parallel reduces bump-steer. Installing longer shackles, lifted springs, or a spring-over axle lift will change your tie rod and drag link angle.

To compensate, you can install a drop Pitman arm, a "Z" thingy (modified drag link) or the Linkage Steering Kit offered by Calmini Products (presently only offered for the Samurai). Any of the these will help to restore proper steering geometry. Installing a steering stabilizer or power steering is not a fix for this problem, it will just disguise it.

[nicbeer]

sweet tech.

What is the theoretical lift before you need a drop pitman arm to be fitted.

cheers

[droopypete]

a standard zook has a bit of B/S from the factory, the more you lift the more you bump.

Also, as DeWiSe is a webwheeler not a tech head, I will let him off,
but disregard the bit about a a "Z" thingy (Z link) helping to restore proper steering geometry,
a properly built Z link, installed corectly,
will do totaly nothing to eliminate B/S,
you need to keep the tie rod and the line of the drag link parallel.
Peter.

[droopypete]

hey look I am a rock god,
I am a rock god,
I am a rock god,
I am a rock god,

Peter (the rock god)

[DeWsE]

a standard zook has a bit of B/S from the factory, the more you lift the more you bump.

Also, as DeWiSe is a webwheeler not a tech head, I will let him off,
but disregard the bit about a a "Z" thingy (Z link) helping to restore proper steering geometry,
a properly built Z link, installed corectly,
will do totaly nothing to eliminate B/S,
you need to keep the tie rod and the line of the drag link parallel.
Peter.

Thanks pete. Bad hibit of Ctrl C and Ctrl V

[Bad JuJu]

Thanks pete. Bad hibit of Ctrl C and Ctrl V

Wots a hibit

[droopypete]

Thanks pete. Bad hibit of Ctrl C and Ctrl V

Wots a hibit

Something New zilanders do a lot
Peter.

[nicbeer]

This being the case.

I am running 2" spring lift with 1" extended shackles. should i look around for one to correct the vagueness of the steering. might be going 2" body as well but that won't affect the steering I don't think

cheers

[DeWsE]

Thanks pete. Bad hibit of Ctrl C and Ctrl V

Wots a hibit

It's a WA thing, no point in trying to explain it as your half developed peanut for a brain would not comprehend it.

[nicbeer]

bump to my last question

[RB zook]

body lift wont affect you steering geometry

[droopypete]

This being the case.

I am running 2" spring lift with 1" extended shackles. should i look around for one to correct the vagueness of the steering. might be going 2" body as well but that won't affect the steering I don't think

cheers

Just drive it and have fun
Peter.

[Toj0]

Not a tech head... Does BS affect coily's as badly as leafy's? Or is the suspension type immaterial?

[Damo]

Not a tech head... Does BS affect coily's as badly as leafy's? Or is the suspension type immaterial?

Whether the vehicle is coil or leaf shouldn't neccesarily have any affect on steering geometry.

[Guy]

Not a tech head... Does BS affect coily's as badly as leafy's? Or is the suspension type immaterial?

Whether the vehicle is coil or leaf shouldn't neccesarily have any affect on steering geometry.

Not entirely true as a coil sprung vehicle "should have" far less bumpsteer than a leaf sprung vehicle, as most tradional linked suspesions run a panhard, making the suspension moves in an arc (why you see big lofted patrols etc with adjustable panhards to keep the dif centred under the vehicle) meaning that during compression and rebound the points that the vehicle steers from should remain at a constant distance from one another. That is if the angles of the panhard and draglink are correct .

Whereas on a leafspring vehicle the diff moves strait up and down meaning that the steering knuckle must move in relation to the steering box ..

Upon re-reading this it sounds like babble ..

if only I had a place to host pics I would draw what I am trying to say ..