Castor Stuffed

[B0oStEr]

I picked up my son's r32gtst from the panel beaters and took it in for a wheel alignment.

The rhs castor is +5.4 deg. and the lhs is +2.8 deg. but the worst thing is the left front wheel is setback 14mm relative to the right front wheel.

Most likely cause is previous kerb damage.

The lhs caster rod and lower control arm have already been replaced.

I spoke to the panel beater and he said the measurements of all the relevent chassis reference points were within 1mm.

This afternoon I spent a couple of hours checking the measurements on a hoist and I cant find a reason for it.

The chassis appears spot on but I measured from one bolt that holds the castor rod to the lower controlarm back to a reference hole in the chassis rail just behind the firewall.

The measurement was 11mm shorter on the lhs which is consistent with that wheel being setback 14mm.

The weird thing is when I measured from the same bolt forwards to the bolt that holds the castor rod bracket to the bottom of the radiator support panel the measurement was identical side to side so that takes castor bush distortion out of the equation.

I can't see what has been pushed back, the measurements don't seem to add up.

If something is bent I can't see it.

I need to pull the lhs castor rod 11mm forward to correct the setback.

Would that give me 3 deg. more castor on the lhs to even things up or more than that?

There are no adjustments yet, we were going to fit whiteline bushes but they don't have that much adjustment but even if I fitted adjustable rods that's only a bandaid not a fix.

This type of damage must happen all the time.

What gets bent?

Anyone out there sorted this problem before?

[B0oStEr]

What is the stock r32 gtst castor?

How much adjustment do you get with whiteline bushes?

[satanic]

Castor Rods or Castor Bushes... I went for the Castor Rods

[B0oStEr]

Thats not really what I need to know.

Either is a bandaid until I fix the problem that caused it to be out in the first place.

I want to know what they are stock so I know whether the right has more castor than it should or whether the right is correct for stock and the left is miles out.

[B0oStEr]

I just got back from working on this tonight.

I found out there is no single cause that is responsible for it being out so much.

Its more a case of all the bolts being pushed to one side of their clearance in one direction accumulating error.

I loosened all the bolts and pulled every thing forward and tightened the bolts.

The set back is now less than half what it was at 5mm.

A set of castor bushes and she'll be sweet.

[foznice]

Thanks for the wrap up, my castor is out quite a little, too and this has been quite helpful

[heller44]

Genius..

Had mine measured today when going over the pits. 15mm back on the left trye as well. (15mm is the limit of what they would allow.)

Will go through all my bolts as well.

[T04GTR]

ok cool. you need to replace the control arm and the caster rod bracket

[sh@un]

Hmmm

[B0oStEr]

heller44

Do you have the castor measurements?

I replaced the castor rod bracket when I fixed mine because I had a spare already but I couldn't see any difference to the old one when they were side by side on the bench so I'm not sure if it made a difference.

In my case the setback on the left was not as much as was measured in the wheel alignment because the right side was set forward 5mm and the left side was set back 9mm but it was measured as 14mm setback relative to the right hand side.

When I undid all the bolts I pulled the castor rod bracket forward as it had been pushed back slightly. I also pushed the front of the left bracket toward the center.

I also loosened the engine crossmember bolts and pushed the crossmember back 2mm as it was pushed forward in the crash.

When the crossmember is pushed forward it actually pulls the wheel backward because the lower control arm pivots on the castor rod.

As I said before nothing moved very far but with everything pushed in the right direction it all adds up.

My castor is now RHS 5.4 deg. LHS 5.0 deg.

I've ordered nolathane adjustable bushes to get it perfect.