Alternative castor correction method

[zuffen]

I need to correct the castor due to a large suspension lift.

Rather than bending the arms I was wondering why we can't simply slot the are's front mounting point on the axle to allow the axle to rotate rearwards.

What I envisage is to slot the locating hole downward on the front of the axle. This will allow the axle to rotate so the pinion moves down, thus correcting the pinion angle and castor in one blow.

Once you have the angle right weld a plate either side of the mount to fix it in position.

I figure there will be sufficient clearance for the track rod to clear the arms as they really don't move too much in relation to each other.

Has anyone tried it and if so did it or didn't it work.

If it ddn't why didn't it work?

[rick130]

Why not slot the holes where the swivels bolt onto the axle tubes ?
I believe Haultech in Qld have a jig to use in the mill so that they can be slotted, and Les Richmond Automotive in Melbourne (Bayswater ??) can also do it or I think they can supply changeover ones.
IMHO, it's the best way to correct it.

[Philip A]

The biggest disadvantage is that the diff angle is not adjusted and the nose is pointing up, which may necessitate a double cardan at the transfer to stop vibration due to unequal UJ angles. Which in turn depending on model may need the gearbox crossmember modified.
regards Philip A

[Loanrangie]

Your method will only change the pinion to t/case angle not the alter the caster, you will still need to slot the swivels to correct this and as Phillip said a double cardan so you wont get shaken to death.

[GRIMACE]

Your method will only change the pinion to t/case angle not the alter the caster, you will still need to slot the swivels to correct this and as Phillip said a double cardan so you wont get shaken to death.

it will alter and correct castor aswell.... its not a bad idea.

[cooter]

it works but u have to weld the old holes up and redrill due to the fact that the hole has to be the same size as the bush hole otherwise they bind on articulation (did this on my last 2 inches of lift ) i pulled one arm down at a time and using a block of copper filled orininal holes with weld then reemed holes out worked fine but with 6.5 inches of spring lift and gq diffs i had to rotete swivels as well how much lift do you have?

[HSV Rangie]

doing this only corrects one issue.

Lifted vehicle has these isues:

1: castor at 0 degrees if 50mm of lift.
2: radias arm to chassy bush under load at all times.

easy option: fit castor correction bushes, inhibits suspension movement does not fix bush at chassy.

next easy opt: fit LRA wedges to suspension resets bush to same angle as rad arm, fit castor correction bushes.

next Best option: fit LRA wedges and rotate swivel housings.

Best option: crank arms to correct pinion angle and also set bush alignment as per std, rotate swivel housings to correct castor.


IMHO.
Michael.

[cooter]

i agree with hsv it would be much better to crank arms and rotate swivels there are numerous ways to correct castor but swivels would be best

[Bush65]

I also agree with HSV Rangie.

PhilipA, front u-joints angles are not equal. They are out of phase to compensate.

By rotating the pinion down, the angle of the u-joint at the t/case is increased and will be more likely to bind when the driver side wheel droops. Then you may have to change to a double cardin joint or a wide angle yoke.

[Philip A]

I misread the original post.
On careful reading, I believe he wants to elongate the holes for the bolts holding the leading arms, then reweld . This would change both the caster and pinion angle.
To answer this question- I have never seen nor heard of it being done but it sounds feasible, although it is of course illegal as are the other methods without an engineers report. Off the top of my head I cannot see any really obvious issues with it.
Regarding the pinion angle- if you raise over 2 inches rotate the swivels and leave the pinion, my experience is definite driveline vibration as the diff nose points up more .
You have to remember when looking at the diff nose while at rest and thinking that the angles at front and rear are not the same , that the axle rotates under power within the leading arm bushes, increasing only the front angle. This brings the front and rear UJs back towards equality.
When you lift the springs this changes the angle at the diff more than at the transfer, sometimes reversing the angle on the diff UJ.
When you then fit a cardan or CV, it works because the front UJ is virtually straight under load because of axle rotation combined with more height.
I still have a front driveshaft for a LT95 at home with a Holden Commodore driveshaft CV at the transfer end , if anybody wants it..CV is rough on take off from Nissan Trials long ago.
Regards Philip A
Regards Philip A

[wilsby]

Anyone knows where I can find the LRA wedges mentioned?

Google didn't help me...

Just the URL would be fine.

[HSV Rangie]

Anyone knows where I can find the LRA wedges mentioned?

Google didn't help me...

Just the URL would be fine.

Les richmond automotive.
http://www.lrautomotive.com.au/home.html



http://www.lrautomotive.com.au/151.html

Michael.

[Michele]

Uhm...time for a dumb Q.

May I modify the swivel balls AND crank the radius arms afterwards?
Or am I getting it wrong?

The swivel housings are already in bits on the workshop to be bored out to accept Longfields.

I have a couple of spare radius arms also but I'm already late and can't do everything at the same time.

If I modify and fit swivels...



...then crank the arms to take strain off the bushes at the chassis mounts...this will not ruin the corrected caster again...will it?

My brain hurts.

[HSV Rangie]

if you crank the arms this will change castor.

bending arms will rotate the axle housing.


Set up axle housing first, get the pinion angle and arm to bush geometry right.
then do castor.

Michael.

[wilsby]

Thanks Michael!

The pics show the wedges mounted in the rear. Will they fit in the front ass well? I'm set with cranked trailing arms, but the front is really limited by the bushes.

[Michele]

Ach!

Thanks!
(again)

[zuffen]

The reason I want to slot the housing mounts is I can't run DC on my front shaft.

I have to run a solid front drive shaft (from the cat converter cars) as the standard shaft will hit my sump (Lexus 1UZ-FE). As the shaft is solid shortening it would be a nightmare.

I can bend arms and ratate swivels but I would still have the pinion angle problem as the diff will still point up.

Rotating the swivels will solve castor but not pinion angle.

Legality doesn't faze me as any mod you make to the suspension should be engineered.

At the moment I run a 4" lift, laminated axles, eye/eye rear shocks, 8x15's with 2" positive offset and none of it has been engineered. I noticed JDM (who built the car) appears to have already done a little slotting and welding.

Funny thing is I've driven this Dakar/Bushy for 11 years and never been pulled up by the Police or RTA as I think it's just too obvious to be illegal!

I think the idea is worth trying as it would be much simpler than dismantling the whole front axle to rotate the swivels. As for bending the arms I wonder what a metalurgist would say?

[walker]

Ok, my turn to jump in with some dumb questions.

"Crank the arms" what does this actually mean?

If you bend the arms, won't this make them shorter?

[HSV Rangie]

When I cranked mine they shartened by 2-3mm not woth worring about.

Arm cranked suit 75mm lift.

Michael.

[Michele]

If you bend the arms, won't this make them shorter?

You can always sort it out with spacers I think...?

[440 BB]

few questions.
zuffen, where did you eventually set your pinion angle to, i read in another thread you were setting the pinion flange vertical at ride height? did you alter the caster at the swivels or leave it as per standard on the partol.

hsvrangie, how did you crank your arms? .
cheers, mat

[zuffen]

Boy this is old!

I endied up using QT Industries 6degree arms and setting the pinion flange parrallel with the output flange on the transfer.

The flanges are basically verticle so the caster angle is also quite good.

I know I should have posted photos of my arms but I haven't seen my car for 2 months and haven't driven it for 7 months!

[440 BB]

cheers mate, found the thread searching on how to set the correct caster, if you can remember back that far, are you happy with how it drives.
cheers, mat

[rustysrangierecks]

Ive got a pair of rotated swivel hubs im not using if that would help. just pm me if you are interested

[440 BB]

im only planning a 2 inch lift, but im using rover arms so wanted to set it correct when i weld the plates on/drill the holes for the bush

[zuffen]

Given the rig is over 2.1metres tall it handles remarkably well.

It doesn't wander (tramline) and is easy to drive.

I haven't had it over 110kmh since doing the changes but I would recommend them.

It also drifts really well in the wet!!!

[defmec]

Boy this is old!

I endied up using QT Industries 6degree arms and setting the pinion flange parrallel with the output flange on the transfer.

The flanges are basically verticle so the caster angle is also quite good.

I know I should have posted photos of my arms but I haven't seen my car for 2 months and haven't driven it for 7 months!

i have bought a set of these arms aswell ,are you still running a 4 inch lift as i am looking to run a 3 inch lift but think that with the 6 degree arms it would be better to go a 4 inch lift on a rrc

[440 BB]

although illegal, i noticed today that the patrol bushes have a larger id, (therefore more room to flex) but have the same id as rover. do you guys think it is safe to have the arms line bored and taken out to patrol bush size, im yet to do any measurements to see how much meat is there but if possible it should improve articulation shouldnt it?

[zuffen]

My car handles, steers and stops extremely well.

It passed the engineering tests with flying colours so it can't be too bad.

[440 BB]

using the same method as cranking the arms (ie heating and bending) do you think it would be safe to do this down at the bush end, between the two bushes to open up the c shape so it clears the patrol axle on the rhs, as i understand it this will limit the articulation slightly by increasing the difference between the two bushes but not by a lot, whats your thoughts?