Help Required! Jag Front End

[sevenohms]

I need some help! I must have done something wrong.

I can't for the life of me believe that 15mm of shims are required for the front end camber.

I checked out my series 1 XJ6, heavily lowered and it has maybe a 1 mm.

I think its a series 1 front end (or early series 2), it had 3 pot calipers. Its running the original crossmember with the center cut out, fitted as original.

I've checked the upper arms and they are on the right way round. Bigger one at the back.

Does anyone have any advice of what I've done wrong???

[Zedn]

Is it sitting at ride height? As it lowers the camber will change.

I have the same set up with the jag series 3. The way mine sits now, i have shims in there and the camber is still way off. I suspect i will need about the same as you so i doubt its much of an issue.

You will know if your upper arms are wrong, they dont fit right on the ball joint the other way. I know, i made that mistake in the beginning.

[Rebel1]

Originally Posted by Zedn

You will know if your upper arms are wrong, they dont fit right on the ball joint the other way. I know, i made that mistake in the beginning.

The series 1 can be reversed but will play havoc with your caster.

[Rebel1]

In my gallery you'll find some pics from a Jag workshop manual of front suspension components.

Might help in assuring you have the proper bits.

[boxhead]

You say it is the original cross member with centre cut out?
Do you have a picture with mods of crossmember?
does it still use the upper and lower mounting points as part of that original cross member?
If teh cross member has been cut in half and a section removed to make the wheel track skinnier, it could be that it wasnt re welded back together level, Ie outer ends higher that original plain, thus moving the upper mounts inbward compared to original.

[Zedn]

Originally Posted by boxhead

You say it is the original cross member with centre cut out?
Do you have a picture with mods of crossmember?
does it still use the upper and lower mounting points as part of that original cross member?
If teh cross member has been cut in half and a section removed to make the wheel track skinnier, it could be that it wasnt re welded back together level, Ie outer ends higher that original plain, thus moving the upper mounts inbward compared to original.

Yes, the centre is cut out of the subframe. You can see it in my gallery.

[boxhead]

My opinion only.
Refer to below pic.


I think when it has been welded back together, it has not been done correct.
If the plain on lower section was not right, then this can move the upper mounts in or out (depending on way it is bowed)
When I said yesterday bowed down, I could not remember which side of mount the jag upper arm bolts too, after seeing picture I can see it is inboard.
So if centre section is too high, this in effect will move the upper mounts outward in relation to lower mounts.

[sevenohms]

Originally Posted by boxhead

My opinion only.
Refer to below pic.


I think when it has been welded back together, it has not been done correct.
If the plain on lower section was not right, then this can move the upper mounts in or out (depending on way it is bowed)
When I said yesterday bowed down, I could not remember which side of mount the jag upper arm bolts too, after seeing picture I can see it is inboard.
So if centre section is too high, this in effect will move the upper mounts outward in relation to lower mounts.

I understand what you have said, I wasn't there when the cut and shut was done, but it was done in a engineering shop that makes tools for automotive (they regularly make tools to 0.1mm). I can only expect that it would be within a few mm.

[boxhead]

Only way you will know is to measure an unmodified one or get the specs regarding lower mont position and upper mount position.
Then measure yours and see if the same offset is present in both measurements.

[boxhead]

Although, 15mm of spacers probably isnt an overly large amount, I reckon I have seen HQ Holdens with more.

[Rebel1]

I agree with Boxhead as to the cause.
Jaguar used to supply castor shims up to 1/8" (3.2mm) for series 1 cars.

Whilst my RMC doesn't use the Jag cross member I have 10.2mm of castor shims.
1 spacer of 1/4" (6.2mm)
1 spacer of 1/8" (3.2mm)
1 standard jag shim of 1/32" (.8mm)

[Zedn]

I dont see what the big deal is as long as the geometry can be achieved it will be fine.

Dave you may be correct. However the factory jag steering rack mounts are used so if it was out by much the mounts wouldn't line up.

[sevenohms]

Its got a jag steering rack shortened by the same amount as the crossmember to maintain the steering angles.

One thing I remembered today when considering the problem, is that it has a XJ40 upright, although I was told by the Jagdaim guy that they are the same?

[boxhead]

Is the Jag rack rubber mounted?
Because an up and down miss align would not show as large a variation at the crossmember compared to at the upper control arm mount.