S1 vs S3 wheel alignment


(JAY COOLE) #1

getting close(hopefully) to taking the S1 xj6 to the shop for an alignment, it has an s3 front subframe.
i suspect the right thing is to have them align it to S3 specs?
anyone have the specs handy?
any pointers for myself or the shop?
thanks in advance


(Frank Andersen) #2

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Indeed, Jay - with the SIII front the SIII specs should be used…

Castor: 2 1/4 +/- 1/4 deg positive
Camber: 1/2 +/- 1/4 deg pos
Toe: 1,6 to 3,2 mm (1/16" to 1/8") toe in…

Actually the same, though unrecorded changes may have been introduced - but I think an alignment shop has the relevant data anyway…

What the shop may not have is the knowledge on ‘old’ Jaguar adjustments how-to…:slight_smile:

Frank
xj6 85 Sov Europe (UK/NZ)
**


(Doug Dwyer) #3

Yes, I’d use Series III specs as well…but remember there are two different specifications depending on early versus late control arms. The change point was at VIN 360xxx or something like that. I’m sure there is archived discussion and info but, from memory, the later spec calls for negative camber and more positive castor.

Cheers
DD


(Doug Dwyer) #4

It’s a bit unnerving to think that a qualified alignment guy couldn’t see how to adjust the settings, as it’s all very obvious. But, you never know.

The likely problem will be finding a shop to take on the job at all. Technically speaking, the settings should be checked and adjusted with the Jaguar-specific “setting links” installed. Since nobody has the links (except maybe a Jaguar specialist shop) a lot shops simply won’t take on the job. The links hold the suspension at xxx-ride height.

The true, real-world importance of using the Jaguar suspension links has long been debated. I’ve had to do some sweet-talking to get the job done sans the links…and have always been happy with the result.

Cheers
DD


(JAY COOLE) #5

thank you for the responses. i was under the impression the S3 had better(slightly) geometry, so i expected the caster/camber/etc to be slightly different.
i suspect, even if available, the jaguar alignment tools/jigs would do me no good as i installed -30mm springs all around and am not at stock ride height


(Paul) #6

On a completely unrelatrd note, it always cracks me up…
When younger, reading and studying the Jaguar manuals to learn to work on my car…and making a mess of things i should have left alone, creating unnecessary issues…etc

…upon reading those damn British manuals and describing i needed to make " a jig" my grandfather always teased me about that.

A man who did all, always working, repairing something type…“whatcha doing laddy?”
I need to do a jig i said…(coming from an earlier generation of slang, for those unaware)

I’ll always remember that and laugh inside.


(JAY COOLE) #7

ah yes…i suspect the term “jig” is now considered politically incorrect and offensive much like jerry rigging probably is as well


(Carl Hutchins, Jr. ) #8

Wow, I am out of date??? I know of some others that surely are, so I’ll not mention them.

Sure does make our language less colorful, Is that a pun in bad taste…

Carl


(JAY COOLE) #9

got my alignment done. the shop set it up for what they termed, better drive-ability and not the stock specs.
they also said, drive it around. see how it feels, and bring it back for more adjustment free of charge.
with the big 1" front sway bar and no rear bar. the rear feels very loose. will need to source an xjs bar or something for the rear. here’s the numbers, if you can read the poor copy.


(Frank Andersen) #10

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Fair enough, Jay…

The specs for rear toe is given in mm, 0,08, rather than degrees. My calculations implies that your rear toe is far to large, and indeed different left/right. As the rear toe is not adjustable, it implies some unwanted slack in your rear suspension. Which may explain a ‘very loose’ rear end - which is not usual for a Jaguar. Only the very discerning would consider adding a rear swaybar - and in your case it may not be a solution…

Apart from suspected rear linkage slack, rear tyres are also a source of rear instability - low pressure or tyre characteristics.

I think you should explore these other avenues before considering installing a possible ineffective rear swaybar…?

Frank
xj6 85 Sov Europe (UK/NZ)
**


(JAY COOLE) #11

ok. good info. thank you. i just have no clue as to what could be the matter with the left rear toe. would the -30mm springs effect the toe? i can swap the side to side easily enough?
the “cashier” at the alignment shop said nothing of the rear toe. he did offer for me to call and speak to the tech directly if i had any questions. i will try calling him this afternoon and see what he has to say.
everything is new out back as well as front. new shocks/struts/sub frame mounts/trailing arm bushings/hub bearings/u-joints/rotors/calipers/etc.
perhaps i or the shop that rebuilt the rear left something loose?
i can swap tires front to rear and put a wrench on everything visible to check. and see if it feels better. the tires look to be in good condition. i don’t feel or hear a broken belt in the tire.
i am open to suggestions on how to correct this.
swap in the rear sub frame out of S3 parts car and see if the car feels better? then swap out the center sections so i have the powerloc 354 rear?


(JAY COOLE) #12

some more random thoughts.
i only had fuel in the left tank and right was fairly empty when on the alignment rack.
nor were these measurements taken with the suspension half loaded and locked in place as in the official jaguar way to do it.
would those account for toe being out? i don’t think so.
it’s likely something bent or loose
as the car is loaded and squats down, does to toe go in or out?


(Frank Andersen) #13

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There is nothing an alignment shop can do with rear toe, Jay - except measuring it. Which they did…

In principle, Jaguar ‘suspension links’ are to be used for suspension geometry readings and adjustments, but as Doug previously said; it’s a bit overkill for the precision required.

However, both tanks should be full, or similar weight put in the boot as a minimum. However, since you mention ‘30 mm springs’ - do you mean the suspension has been lowered?

While ride height should have no/minimal effect on toe; in this situation I think it is pertinent to measure rear ride height. Which should be 189 mm +/-6,4mm from the tie plate to ground - which is close enough to the expected height with the setting links as makes little difference.

However, camber angle is adjustable, and is affected by ride height; so the difference rear left and right may explained by an empty 'right tank. And is likely of no significance for car handling.

As said before; I’m not sure how excessive rear toe would affect rear end stability. But as rear toe is specified to 'parallel +/- 0,008mm - rear alignment its unlikely to be immaterial. The alignment chart shows about the same toe front and rear left. so unless the shop went wild on front alignment; the rear left toe is somewhere between 0,8 and 1,6 mm - which is some 100 times the spec. And the rear left and right difference won’t help either…

With all new relevant parts at the rear, the wrong toe is ‘odd’ to say the least. One question arising is why the rear was overhauled - and of course what may have gone wrong in the assembling.

The fact that you consider the rear ‘very loose’ implies that you are not imagining it, being too pernickety - and the alignment chart shows a possible/probable reason. A main point here is that a Jaguar should not be ‘loose’ whatever the load and ensuing ride height variations.

While non-standard springs, shocks and tyres may affect rear end stability; they have no bearing on rear toe anomalies.

An obvious test is to verify rear hub play, jacking up the car and check for tyre wobble. While it would be ‘unthinkable’ for a shop to get play wrong; excessive play would certainly affect toe and rear end handling - but it is quickly checked…

Beyond that, brute force to check for movement is one way forward, particularly inner and outer pivot points - but if nothing is detected I’m at a loss. Put together properly with undamaged parts, and mounted correctly; there are no explanations of why the toe is wrong…

Frank
xj6 85 Sov Europe (UK/NZ)
**


(JAY COOLE) #14

yes, suspension lowered 30mm.
now that i have the car running and driving a bit better, i will get under it and measure a few things and look for a jag shop in town that maybe can better see what’s wrong.
rear and front suspensions were rebuilt due to what appeared to be 47 years of neglect.
it was past due


(Frank Andersen) #15

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The specs given are for the ride height set with the setting links, Jay - or around the normal ride heights…

While the car is meant to drive perfectly with a variety of loads and suspension travels - with minimal variation in geometry. It still requires the geometry to be set at prescribed levels - measured at your present ride height the readings may be inconclusive…

You don’t mention why the lowering was done on an otherwise very low riding car (front and rear?). The setting links are likely not strong enough to lift the car some 30 mm - and jacking up is not a solution as the car must be rolled for the suspension to settle…

All that said; if the rear toe is that much out, it may cause the behaviour mentioned - the problem is to sort out is this is caused by the lowering, or by some rear end fault. In the latter case just resoring the right height may afford no improvement…

Frank
xj6 85 Sov Europe (U/NZ)
**


(JAY COOLE) #16

may have found the issue. the shop that rebuilt the rear had a tech whom after dropping the universal joints and having a cap or 2 spill out the needle bearings, simply replaced the cap with a similar but ill fitting u-joint cap.
there was a lot of play overall in the wheel, to the point it acted like the hub nut was not tightened.
this has been corrected with all new spicer u-joints installed and the car feels and drives better. need to get it back on an alignment rack and check it again