caster camber problem

steve h · Post by **steve h** » Mon May 11, 09 11:12 pm

Tried to adjust caster & camber, started on the right hand side
rear bush all the way in front all the way out turned front bush back in
until camber gauge read zero, went to adjust left hand side rear bush in
but the front bush wont turn out like its under tension keeps springing
back in, even with the front bush all the way in camber gauge reads
2 deg pos ? got it sitting dead level,and that took ages.
just wondered if I'm doing something wrong,

Pete · Post by **Pete** » Tue May 12, 09 7:54 pm

This comes up time and time again.

My personal view is to set the front end up with as much caster as possible for directional stability. If you try to get the camber right you will loose all the caster as the design is not flexible enough to accommodate both parameters.

steve h · Post by **steve h** » Tue May 12, 09 8:43 pm

Pete wrote:This comes up time and time again

sorry i was just a bit worried about the pos camber

Pete · Post by **Pete** » Tue May 12, 09 9:39 pm

It is worth trying to use the "search" facility on the website to bone up on previous threads - you will still have to reach your own conclusions on how you want to go about the set-up

Anonymous · Post by **Anonymous** » Tue May 12, 09 9:55 pm

I would'nt worry about castor just concentrate on camber , maximum castor on these ole mopes won't set the world on fire......... & with power steering it won't self centre anyhows.

Pete , gonna take a rain check on any geometery setting you care to share with us.

Dave-R · Post by **Dave-R** » Tue May 12, 09 10:16 pm

It is simply not true that you will loose all caster if you dial in a little negative camber. You will only loose a little.

Start by setting the caster to max each side and then bring the camber in to zero. if you want to corner fast add a half degree of negative camber.

What worries me is what the others have completely missed in your post. it sounds like one of the bushes is seized or something.

Anonymous · Post by **Anonymous** » Tue May 12, 09 10:21 pm

The more castor you put in the more the A arm will spring back , take the load off the front end.

...................or get someone to hold the adjuster rod while you tighten the nut.

& Dave , stop scaremongering.

steve h · Post by **steve h** » Tue May 12, 09 11:30 pm

Thanks for the replys

one side was easy no problems took about 10 mins
max caster turned front bush back in until gauge read zero
didn't need to turn it back much i thought this is easy

On the drivers side tried to do the same but the front bush tries to spring
back, so tonight i removed the bolts and started again, rear bush in
front out but still it tried to spring back so i set it in the same position
as the other side checked camber and it was 2 deg positive the other
side is zero, i turned the front bush back all the way and still get 1/2 deg
pos camber

The tracking looks way out , could this be the problem?
could i disconnect the track rod end and try it ? this was all done with the
weight off on blocks of wood under lower arms, copied from dave.

Anonymous · Post by **Anonymous** » Wed May 13, 09 1:37 am

Hi Steve,
due to the position of the track rod end in relation to the spindle you may find that the effect of bump steer is affecting the rotation of the adjuster bolt.
IE depending which position you are in the suspension travel due to the block the track rod may be iducing a load.
The bump steer can be significant.
I would remove the track rod end and try again don't forget to set the toe in with the car on the ground without any blocks.
If you look at the top wishbone mount on the shock tower you will note the forward adjuster is 30mm higher off the chassis leg than the rear one.
this equates to 12 degrees from the horizontal.
As the lower arm operates straight up and down the effect is to move the top spindle pivot point backwards as the suspension compresses inducing about 1.5 degrees of Castor under full compression.
The only other influence on the suspension is the torque arm.
When under load the moment is trying to pull the top wishbone outwards Unload the torque arm by jacking under the the chassis this may also help.

Matt · Post by **Matt** » Wed May 13, 09 7:12 am

Talking of tracking, you must reset your tracking after caster/camber adjustment, as it is now likely to be way, way out .

steve h · Post by **steve h** » Thu May 14, 09 8:51 pm

Some good info, really appreciate it

unfortunately the weather and work has stopped play

I will have another go at the weekend , weather permitting.
I've found somewhere that can check it with digital equipment
but they don't want the job of adjusting it

steve h · Post by **steve h** » Tue May 19, 09 9:42 pm

Managed to get the camber set to zero double checked using a plumb bob.
but it still doesn't look right.
The uca cams are not a mirror image,
the left hand front bush is all the way in,
the other side is nearly all the way out

Dave-R · Post by **Dave-R** » Tue May 19, 09 9:44 pm

The next question would be are any of the suspension parts or chassis bent?
In particular one of the LCAs?

Anonymous · Post by **Anonymous** » Tue May 19, 09 11:01 pm

Naughty Al had the same problem , two different lower control arms were used , had about an inch difference in the length beween driver & pas side , he ended up raping Bobs Bee for the LCAs.

steve h · Post by **steve h** » Wed May 20, 09 1:01 am

The first thing i thought was somethings bent, had a quick check but
couldn't see any thing obvious.
But thinking about it a couple of years ago i replaced all the bushes
and ball joints, and had them pressed out at a local engineers,
they ruined one of the arms, thought it was the top one but can't be sure?
cant even remember where i got a replacement from.
I will have a measure tomorrow.
Thanks guys