Suspension misalignment

[Albion]

Hi guys,

This might not be an S Type question, however given both the MkII and S Type share the same front end suspension I wonder if anyone ever experience some sort of tyre fouling the wheel arch and what can be done about it. Myself I do not recall ever having such an issue with my S Type. But it has been dismantled for a few years now, however a friend of mine who has just restored a MkII is experiecing this and it is rather annoying.

[NigelW]

Sounds like the springs are worn out. The only other thing that comes to mind is the wheel arches if it has replacement items that have been welded on incorrectly. Any photos of the car?

[Albion]

No detailed picture sorry. Apparently it is a very common problem with Mk II. Hope I will have no such issue!

[cass3958]

Can you give us a bit more information about where the tyre is fouling the wheel arch and how?

Does it foul the arch whilst sat still dead ahead or when the front wheel is turned on full lock? Does it foul the outside edge of the wheel arch or the inner wing. What size tyres has he put back on the car? Wider than standard 185? Does it happen on both sides or just the one?

Sorry for all the questions and I know it is not your car but without this information it is difficult to suggest a remedy.

On the S type and I presume the same for the Mk2 the front subframe is located on the chassis by four rubber mounts. The two at the front dictate its position front to rear. The two at the back dictate its position side to side. These can only go in one way if you want to do up all the bolts, so the subframe cannot be out of position. All the components on the subframe have set bolts and distances so unless he has bought aftermarket parts which are to long or short I do not see how the wheels can be out of line. There are spacers to adjust some sideways movement(castor angle I think) in the upper wishbones but not enough in my opinion to allow a tyre to foul the arch. When I rebuilt mine and I had steel wheels on, I changed my front brakes and hubs to those from an XJS. Bigger discs, pads and calipers. The calipers were wider than the original Dunlop calipers on the S Type so I had to put 1/2 spacers between the hub and the wheel. I once had a problem with a tyre touching the underside of the wheel arch on full lock going over a bump. I have now gone to wire wheels and changed back to the original S Type hubs and Dunlop calipers as the XJS hubs did not allow for wire wheels and even though I am running 205 tyres and lower springs on the fronts I have not had anymore touching problems.

Has he changed the original lever arm steering to a rack and pinion steering arm? If so this could be allowing the steering wheels to turn too far and foul the inner wings on full lock?

Sorry so many questions but to give a more accurate suggestion as to how it might be cured we need more information on the symptoms.

[cass3958]

Sounds like the springs are worn out. The only other thing that comes to mind is the wheel arches if it has replacement items that have been welded on incorrectly. Any photos of the car?

I came across this S type at a JEC meeting a couple of years ago. It is owned by the then secretary of the JEC SW branch and he was not aware until I pointed it out that someone prior to his purchase had put repair arches on the front wings of his car from a Jaguar 420. The 420 arches are square topped instead of the round wheel arch on the S Type and Mk2. It was really noticable when the cars were side by side but he had not noticed it before.
The 420 has the same front suspension set up as the S type so even with these slightly lower square arches they do not have touching problems that I am aware of.

[Albion]

Hi, I will be getting more information and possibly some pictures. Both mug guards have been changed and it runs on wire wheels. I will check size as well.

[Glyn Ruck]

The common causes of wheel fouling are.

1) Poorly repaired crash/rust damage.
2) Oversize tyres,
3) Incorrect offset wheels fitted.
4) Sagging springs that have lost their factory spring rate.
5) Collapsed subframe mountings
6) Bump stops missing
7) Modification from standard as cass says.
8) Incorrect steering lock stop adjustment.

A combination of the above.

[Orlando St.R]

During restoration, I made the (incorrect) assumption that the springs would be worn out after 50 years and replaced them with new ones from SNGB. I had the problem of the wheel scuffing the wheels arch that you describe, Albion.

So, I then spent ages trying to find a set of original springs in decent condition and in the end found a pair from a 420 which I had tested and confirmed they matched the original spec (and each other). Problem solved.

The rule of thumb is that you should be able to get three fingers between wheelarch and tyre. If you have less than that, you are likely to have problems.

As an additional complication, original springs for Mk2s came in a variety of 'colours' - paint marks, depending on their length, presumably because they could not make every spring exactly the same length. They then had a number of packing rings inserted above the spring, depending on the spring colours. The 420 springs I found were not marked in accordance with the recorded colour scheme, so I just fitted one 1/8" packing ring on the right hand side on my RHD car.

SNGB have assured me that their new springs are now to the correct spec, but perhaps your friend bought them a while ago or perhaps they are tired originals.

With new (2014) SNGB springs:

IMG_9109_smaller.jpg (189.41 KiB) Viewed 6461 times

With original 420 springs:

WP_20180520_14_51_35_Pro_small.jpg (214.95 KiB) Viewed 6461 times

To summarise all my ramblings, if you cannot get three fingers between the tyre and wheelarch, the problem is likely to do with springs; if you can get three fingers between the tyre and wheelarch, it is likely something else, like the extent of travel of the rack and pinion steering.

[Albion]

Thanks guys, when possible I have a look at it an give you an update.

[johngosnell]

It is interesting that SNGB are saying that the springs are now correct, I had my springs replaced along with all new poly bushes and sub frame mounts last year, and even though I had the spacers removed my care site high similar to the grey car in this thread.


john 1B1257BW