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#1 Castor adjustment
Posted: Sun Oct 15, 2023 7:28 am
by Paul bow
Hi guys..
I seems to me after a full rebuild that the castor needs adjusting on the steering. I say this as you find yourself steering yourself out of a corner rather than the wheel centring itself.
I understand ideal is 2 deg positive.
I have no idea how to take this measurement.. any help gratefully received.

#2 Re: Castor adjustment
Posted: Sun Oct 15, 2023 7:38 am
by mgcjag
Hi Paul....already covered quite a lot on the forum. ...see similar topics below and this one
viewtopic.php?f=3&t=19194
you need a camber/caster guage....the service manual tells you how to adjust the upper wishbone....Steve
#3 Re: Castor adjustment
Posted: Sun Oct 15, 2023 1:12 pm
by Paul bow
Thanks Steve much appreciated

#4 Re: Castor adjustment
Posted: Sun Oct 15, 2023 6:50 pm
by chrisfell
I used a plumb line (and basic trig) hanging close to the top and bottom ball joints with the car on a level surface. It is accurate enough to set each side to within manufacturers tolerances.
#5 Re: Castor adjustment
Posted: Mon Oct 16, 2023 6:03 am
by Paul bow
Hi Chris.. could you elaborate on that a bit more for me, sounds like just the approach I’m after

#6 Re: Castor adjustment
Posted: Mon Oct 16, 2023 7:47 am
by mgcjag
Hi Paul....have a read here..and the JL link it may help and it explains Chris useing a plumb line..Steve
viewtopic.php?f=4&t=10542&hilit=Castor+adjustment note a good starting point is 1/2in thread showing at the front of the upper wishbone adjuster.....
#7 Re: Castor adjustment
Posted: Mon Oct 16, 2023 4:14 pm
by eddiecross
If you can borrow a caster/camber gauge....(I'm in Egham!)
This is how I set the castor and camber. Jacked to level across the car and at the correct ride height
Also Trackrite tracking gauge
Regards
Eddie
#8 Re: Castor adjustment
Posted: Mon Oct 16, 2023 7:03 pm
by Paul bow
Thanks Eddie I was looking at that gauge on machine mart.. pleased to hear that it comes recommended, and thanks for the offer.
I have very little knowledge on this as you are about to find out, infact I just picked the car up from Northampton motorsport who were going to set it all up for me, unfortunately their technical wizardry equipment did not clear the wire wheels, hence… I’ll do it myself.
Anyhow the question i can’t get my head around is why does the ride height have to be that as the same as it would be on its wheels on the floor for the adjustment on the castor?
I would have thought so long as the axle stands are under the bottom wishbone thus compressing the torsion bars and the car is level from front to back that would be ok?
Sorry, probably a really straight forward explanation and I’m making an easy job difficult!

#9 Re: Castor adjustment
Posted: Mon Oct 16, 2023 7:41 pm
by mgcjag
Hi Paul.....Jaguar give settings in the manual based on what they call "mid laden height" useing setting links to reproduce this height....however in my opinion its better to set up the car as its typically driven...driver only. with a passenger or fully loaded.....so load up you car to suit then do all your settings.....or just use the setting links..your choice..sitting on its wheels on slip plates is the easy way... Steve
#10 Re: Castor adjustment
Posted: Mon Oct 16, 2023 8:38 pm
by Paul bow
You know what Steve.. I’ve restored this any many others from complete wrecks, but this castor alignment is doing my head in !!

Setting links? Sorry but I’m a miss as to what these are..
And the tool that our friend above has shown in the pic is mounted on the disc, wheels removed..
I’ve got the technical data just struggling to know the method, having read other posts on it I’m still none the wiser.
I’ve got it how to adjust the castor but it’s the measuring of it that’s defeating me.
In desperation I called JD classics being just up the road thought I’d just put it in there after the disappointment at Northampton..
The guy there informed me no problem but it’ll be 2 days work, at least, I didn’t have the courage to ask what the hourly rate was !!

#11 Re: Castor adjustment
Posted: Mon Oct 16, 2023 9:15 pm
by Series1 Stu
Hi Paul.
The setting links are to ensure that the car sits on the floor, which must be level, with the factory ride height settings. This is important because it affects the castor angle. This can be explained if you imagine raising the rear wheels off the ground while the front wheels are still on the floor. You can see that the upper wishbone will rotate forward around the axis of the stub axle thus changing the inclination of the stub axle carrier and, therefore, the castor angle.
Regards
#12 Re: Castor adjustment
Posted: Mon Oct 16, 2023 9:31 pm
by abowie
Paul bow wrote: ↑Mon Oct 16, 2023 8:38 pm
The guy there informed me no problem but it’ll be 2 days work, at least, I didn’t have the courage to ask what the hourly rate was !!
Bollocks. It should take perhaps 15 minutes.
viewtopic.php?f=3&t=14168&p=116037&hili ... en#p115191
#13 Re: Castor adjustment
Posted: Tue Oct 17, 2023 1:59 am
by DWW
They gave you 'a not interested in the job' quote
#14 Re: Castor adjustment
Posted: Tue Oct 17, 2023 3:19 am
by abowie
DWW wrote: ↑Tue Oct 17, 2023 1:59 am
They gave you 'a not interested in the job' quote
More than likely it was so they could drive the car to the wheel alignment shop one day and pick it up the next.
#15 Re: Castor adjustment
Posted: Tue Oct 17, 2023 4:15 am
by Paul bow
abowie ..’drive it to the shop and pick it up the next!’
That made me laugh ..


#16 Re: Castor adjustment
Posted: Tue Oct 17, 2023 6:48 am
by flatfloor 3.8
Hi, i have all the equipment needed to do this job ( turntables, camber castor gauge, setting links Etc ) you are welcome to borrow them. I live in Thorpe Bay, Essex.
Bill
#17 Re: Castor adjustment
Posted: Tue Oct 17, 2023 4:31 pm
by chrisfell
Paul,
The link to Jag-Lovers hasn't got this photo.
Sort of helps to see exactly how i did it.

#18 Re: Castor adjustment
Posted: Wed Oct 18, 2023 4:05 pm
by Paul bow
Many thanks guys great help as ever..
And Chris that picture explains exactly how you did the job, much appreciated.
Apparently moss (Angus) are in the process of an all singing and dancing set up, and should be up and running in a few weeks, I might hold off till then, thanks all
