Steering Castor improvement/mod

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Author Topic: Steering Castor improvement/mod  (Read 2319 times)

Offline seany-boy

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Steering Castor improvement/mod
« on: October 20, 2021, 01:11:10 pm »
It seems like ShaunP has not been on the forum for a while and so I thought i would ask the broader audience regarding steering, in particular the Castor improvements for radial tyres.
I finally got around to pulling out my pwr steering control valve and following Shaun's instructions I put in a washer on the bumper to reload the bumper spring. I like the fell better now and it is definitely smoother as it seemed to be binding up a bit before. Thanks for the guidance.
I have seen a few posts abut increasing the caster to between +5-7 deg and was thinking of trying this as well- just a road driven car. But I had a couple of questions if you have time.
1. I think I read i can add a couple of shims using existing front bolts by changing the nut to a nylock or other lock nut or do I need to change the bolt? Also can this be done with the springs etc loading the UCA or do i need to remove the springs?
2. I also read about shortening the tub eon the castor rods between the nuts by about 1/8 inch. Is this to allow greater tension on the castor rod or to allow it to come forward further?
Is there anything else you recommend for a street car steering? I had the steering box rebuilt not too long ago as well.
Any thoughts welcome

Offline barnett468

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Re: Steering Castor improvement/mod
« Reply #1 on: November 10, 2021, 04:34:08 am »
Is GLENN on sabbatical too?

Sorry but I have not been on here lately either and just now saw your private message.

You can leave the arms and springs on the car to install shims and as long as the end of the bolt is either flush with the arm or protruding thru the arm you are ok as far as bolt integrity goes.

Sometimes it is easier to jack the car up a little on the side you are working on to relieve some of the pressure of the wheel forcing the arm into the shock tower.

You will also likely need a long pry gar and/or big hammer to manipulate the arm away from the shock tower enough to get the shims in.

The rod going from the lower arm to the body is not typically used to adjust caster.

What do you mean by "tub"?



« Last Edit: November 10, 2021, 04:40:05 am by barnett468 »

Offline seany-boy

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Re: Steering Castor improvement/mod
« Reply #2 on: November 10, 2021, 07:48:00 am »
bad typing! I meant the tube on the castor rod that goes between the nuts and rubber bushes, I had read that it needed to be shortened 1/8 inch as well?

Interesting that the rods don't adjust castor, shows what I know about steering!

Offline Dwayne

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Offline seany-boy

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Re: Steering Castor improvement/mod
« Reply #4 on: November 10, 2021, 09:30:19 am »
Thanks Dwayne ,

Everytime I read that article I learn more. So it looks like the 1/8 inch reduction to the sleeve is only 64-66 from my read?.

Offline barnett468

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Re: Steering Castor improvement/mod
« Reply #5 on: November 10, 2021, 12:45:22 pm »
you also don't want less than 1/4" (6mm) of toe in because the tires toe out as speed increases unless you have heim joints on both lower strut rod ends etc.

you can buy stiffer strut rod bushings which will reduce the movement of the lower arm some.

Offline seany-boy

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Re: Steering Castor improvement/mod
« Reply #6 on: December 11, 2021, 09:25:22 pm »
Thought I would provide an update on the caster story. Thanks for the input from Barnett and also Justang and Kerry.

Because I wanted to do the shims with the UCA still in the car it was not possible to remove the bolts. By using stands to take the weight of the car I was able to separate the UCA balljoint and drop the weight off the UCA which allowed me to put shims in.  I used cone lock nuts and removed the washers on the front bolts while leaving the rear bolts as standard. I was able to put 8mm of shims on each UCA then used loctite on the cone locknuts.
Pretty easy job in reality.

I now have between 5 and 5.5 degrees caster - up from about 2 deg previously. The vehicle is more settled on the road and a little heavier - or less light- in the steering. The power steering has always made the steering a little light and floaty, almost overdriven by the power steering pump which is common apparently.
I left the tube on the strut rod as I have poly bushing on the rod but might look at doing this in the future if the bushings fail.

Offline barnett468

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Re: Steering Castor improvement/mod
« Reply #7 on: December 14, 2021, 03:12:59 am »
Good news, glad it wasn't hard.

Yeah, being able to turn the steering wheel with just 1 finger is a little extreme, lol.