Another S Type Low at the Front

[sweller]

Over the last 12 months I have replaced all the front suspension components - springs, dampers, wishbone bushes (top and bottom), V blocks and front sandwich plates, roll bar washers and rubbers.

The new springs from SNG have two packing pieces (Driver's side has one thick and one thin = 3/4", passengers has two thin = 1/2")

Yet the bloody thing still scuffs the (standard on steel wheels) front tyres on cornering or potholes. I can only just get one finger between tyre and wheel arch. Worse two up.

Any ideas?

[piman]

Hello Simon,

if you want more ride height I would get some additional spacers.

My copy of the Jaguar parts lists two different springs and from the chassis numbers there was a revision after the first few hundred cars. It also says that the springs are colour coded for length and spacers are required depending on grade with one grade requiring zero spacers.
The spacers are 1\8" or 1\4" thick, part numbers C 11874\1 and C 11874 respectively fitted to the top of the spring.

I assume that modern replacement springs will not be graded as original?
The other aspects are what is the camber set to as the more negative you go the further the top of the tyre will move away from the wing, and what size tyres you have fitted?

Bear in mind that even with a greater ride height that on bump the wheel will move into the wings so if it does scuff now it probably still will. You may need to dress the wing flange to totally remove any conflict unless your camber is excessively positive?

Alec
.

[Martec]

Hi Simon,

The shim thickness seems excessive and you would need an extra 1/2" on each to gain anywhere near the correct height (3 fingers).

Suggest you check the wire thickness as it should be 0.635" for a 3.4 or 3.8 MkII so assume similar for an 'S' type (I had undersize springs, think they were daimler 250 springs that upset everything).

The other alternative is that someone has fitted XJ6 front uprights to get better brakes, apparently they will fit but the stub axles are in a different position and leave the car low at the front (thats the reason 420 uprights are used to use bigger calipers and keep the correct height.

3 Fingers is a reasonable guide IF the wings were fitted evenly???? the handling is at its best if the lower wishbones are horizontal (a bit of wood across both lower wishbones is an easy check).

Best of luck

Brian

[sweller]

The shim thickness seems excessive and you would need an extra 1/2" on each to gain anywhere near the correct height (3 fingers).

My mistake on the shims - they're 1/4" (pass) and 3/8" (driver) - I'd counted each one as 1/4" not 1/8"

I suspect the springs are not up to the job - I'll give SNG a ring as they supplied them. I'm getting a bit fed up as it's not the first time I've taken the springs out and it's a bit of a chore.

Once to replace the sagging originals, again to replace a broken new one (which SNG replaced), again to do the wishbone bushes and now it looks as if it needs doing again!

[J44EAG]

Why not try the Watjag front springs as an alternative?

£114 a pair. Details on the back inside cover page of our latest May 2012 magazine.

Mike

[XjRestorations]

Hi Simon,

Where is the wheel scuffing - top of the arch I assume - not the front or rear of the arch?
Uprated springs are a very good upgrade - but standard springs should sit the car at the correct height and stop all rubbing anyway.
You say standard wheels - what tyre sizes are you running?
As Brian has already quizzed - are XJ uprights used - or is the car all standard?

All the best,
Keith

[sweller]

The uprights are standard as are the tyres, it has 185/15 Vredsteins on at the moment.

The scuffing is at the top of the tyre/wheel arch lip.

It has pattern springs from SNG Barrat (C21958 according to the invoice from last August).

[XjRestorations]

Hmmmmm - and it rubbed before you changed for new springs?
I have a lot of time for SNG, but some repro parts are simply no good.
I would still be thinking a spring issue as the wheels/tyres are correct, and the uprights are correct.

[piman]

Hello Simon,

the springs are a bit of a red herring in some ways, if the tyre touches the wheel arch there is simply insufficient clearance. If the camber is too much positive, shimming the top wishbone to correct that will pull the top of the wheel inward. If it is correct the arch will need to be dressed, if possible. I assume it is the same both sides?

Alec

[sweller]

Measuring camber seems to be pretty tricky on an S type due to the enclosed rear wheel arches. Any suggestions where to get that done?

My car has had a new wheel arch section at some time in its life as I can make out the join. It does have a marked lip, this seems to be what catches the tyre edge. Hooray for ASCII art.



Ideas?

[sweller]

Another thought....

Given it has had replacement wheel arch sections at some point I'm making the dangerous assumption they've been welded in the correct place. Sure, they look fine but are they?

So, if the car is parked on level ground what's the distance between the bottom of the front cross beam and the floor?

If the suspension is correct I'm guessing the beam height will be correct. If the problem is the pronounced 90deg 1" lip on the wheel arch that can be judiciously, err, bent out of the way.

I would have also thought even if the springs were sagging it would hit the bump stop (of which it has a full set) before the wing?

[piman]

Hello Simon,

on full bump the top of the tyre will be inside the wing, even with the 'three fingers' ride height the suspension will surely travel more than that which is why I said the springs are a bit of a red herring. A 1" lip on the wing sounds a lot and I would think that could be dressed or trimmed to give clearance for the tyre?

As far as camber goes as it is the front we are talking about, you could get a fairly accurate assessment by using a builders level, although it will need a flat level surface to do a check, otherwise anywhere that can do an alignment for you?

Alec

[XjRestorations]

The wheelarch should surely have a 180 degree return along the upper radius of the arch - the same as the MK2's. A little while since I have got my hands on an S-type - but I am sure there should be no 90 degree return through the centre of the arch radius?

[ecosselynx]

Hi Simon

Your 1" lip is your first problem, I've come across a couple of Mk2 that have had the top wing section let in and they didn't roll it back and trim off the excess. you don't want to fold it all the way over as it will only make a water/mud trap.
Someone really into body work might be able to offer up a solution to help resolve it with minimal work/damage to the paintwork of the wing, I'm sure this will stop you scuffing.
As to the spring height, my own car has uprated springs, although about 13 year old now I still get two fingers between tire and wing and I run with wires that are another 1/2" wider in track and have no scuffing.
If the wire dia of your springs are correct, you can only then check them off against a verified good spring by cross checking the poundage at various points during compression, this would tell you if the temper was correct.

[XjRestorations]

The lip can be carefully dressed back with a dolly. heating the paint along the lip can often soften it enough to avoide any cracking in the paint. Gentle dressing is required, the lip should not be a tight return on itself, but a gentle 'U' shape return. Normally, this 180 degree return runs from approx. 10 oclock to 2 oclock on the arch.