[xj40] Front wheel alignment

XJ40
1

Continuing my investigations into tyre wear, I am looking at
the wheel alignment.

Alignment should be done with the front sub-frame pulled
down to 150.8mm above the ground, right?

Well, what if the clearance without loading/pull-down is
already less than 150.8mm???
Mine seems to be only 135/140mm above the ground!

Could this be weakened springs? Or could it be the tyre
rim/wheel size - I have 225/55/16. Was this the original
spec? I seem to remember the previous owner saying he had
changed the wheels to 16in - would that have been from 15inch?

I know my speedo over-reads by about 8% possibly suggesting
smaller final tyre diameter, could this account for the
lowness of the sub-frame?

Also, can I check the correct toe in - it should be between
parallel and 1/8 inch (~4mm)? - and that it best should be
set at the higher end of toe-in as speed tends to toe-out
the tyres?

TIA–
Mike. '92 Soverign 4.0 RHD
London, SW17, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

2

In reply to a message from MikeSW17 sent Tue 1 May 2007:

I have always measured distance in between tires and adjusted toe
that way, I have noticed that at least twice a year this car gets
out of alignment somehow. My method does not get 100% accurate
results, but good enough to prevent excessive tire wear.–
The original message included these comments:

Continuing my investigations into tyre wear, I am looking at
the wheel alignment.
Alignment should be done with the front sub-frame pulled
down to 150.8mm above the ground, right?
Well, what if the clearance without loading/pull-down is

–
Patrick Mcclure 1989 XJ6 259,600 Jasper, GA
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

3

In reply to a message from MikeSW17 sent Tue 1 May 2007:

Well, it’s not the wheel alignment.

Swapped the N/S front and rear tyres. Drove the car for a
few minutes no problem.

Returned and swapped the O/S front and rear tyres… OOPS,
on moving off the car veers heavily to the right, needs
several ounces of pressure on the steering wheel to pull the
car to straight.

So off to the local tyre shop.

‘‘Hi, can you do me a wheel align?’’
‘‘No, not on a Jaguar, needs special equipment.’’
‘‘Right, but I know there’s something wrong. I just want a
‘best effort’ set-up I can work from. Anyhow, it’s already
less than 150.8mm from sub-frame to ground.’’
‘‘Ok, well if that’s what you want…’’

The alignment was well off, toe-in ~8mm. Chap adjusted it to
roughly parallel - ignoring my suggestion that 3-4mm toe-in
would be nice - but then I couldn’t understand much of his
language, why should he understand mine? :wink:

‘‘Take it out for a drive, see how it is’’ (I think he said)

Much better, still pulling to the right but only needs
finger-tip pressure on the wheel to correct.

Under braking the pull to right vanishes, but is constant
under acceleration/constant speed.

Chap put it back on the ramp and got the inspection light
out. Showed me that the rubber round the bottom O/S wishbone
bearings was squeezing out round the bolt head - didn’t look
good compared with the N/S one.

All this for free - no charge (just the price of a pint or
two in the mans hand) - didn’t expect that from a
high-street tyre ‘specialist’.

Anyhow, problem diagnosed, not alignment but camber angle
which was suspected (by me and you lot), but I didn’t much
want to hear.

Any ideas how much changing the wishbone bushes might cost
me? My local garage guy started mumbling ‘‘oh, seized pins
big job, hard work’’ (he usually gets sad and complains he
didn’t charge enough for the last job) before asking me to
bring it back on Friday to get it on the ramp for a look.

Not too sure, but I think this job needs the front spring
compressor tool? I don’t think they have one…

Might take the car over to Surrey Jags tomorrow see what
they have to say.

I think I only need to do the O/S ones (soon) as after
swapping the N/S wheels there was no noticable change in
steering - although the N/S tyre wear seemed similar?–
The original message included these comments:

Continuing my investigations into tyre wear, I am looking at
the wheel alignment.

–
Mike. '92 Soverign 4.0 RHD
London, SW17, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

4

Hi Mike,

I don’t understand how bad bushes on one wishbone would cause a camber
problem on both sides and wear to the outside edges of both front
tires. Certainly too much toe in WILL cause wear of the outside edges
of both front tires.

It is NOT necessary to use any special tools or bother setting the ride
height to a particular value to set TOE, as the toe does NOT change
with wishbone angle. The tie rods are parallel to the lower wishbones,
and therefore the tie rod length to the steering arm does NOT change
with up/down motion of the wishbones.

It IS necessary to have the suspension (wishbones) at the correct angle
to properly measure or set either castor or camber, as these do change
with wishbone movement/angle. However, the crossbeam height of 150.8mm
relate to that height with the specified tire profile. If you have
lower profile tires than the original specification, the crossbeam
height will now be lower than 150.8mm with the same (intended) wishbone
angle, and it is the wishbone angle, and NOT the height of the
crossbeam above the pavement, which is critical.

Therefore, if you have changed from the original wheel size and/or tire
profile, adjustment of the specified 150.8mm crossbeam height must be
made to attain the proper wishbone angle.

The XJ-S, and I believe also the XJ6 through the Series III, provided
for special links or spacers to set both the front & rear suspension at
the correct wishbone angle to measure or adjust castor & camber. I
haven’t seen any discussion of such tools in the XJ40 Service Manual.

George Balthrop, Clifton, VA USA
85 & 89 XJ-S Coupes; 89 XJ40 VDP-----Original Message-----
From: michael.higham@virgin.net

Swapped the N/S front and rear tyres. Drove the car for a
few minutes no problem.

Returned and swapped the O/S front and rear tyres… OOPS,
on moving off the car veers heavily to the right, needs
several ounces of pressure on the steering wheel to pull the
car to straight.

So off to the local tyre shop.

‘‘Hi, can you do me a wheel align?’’
‘‘No, not on a Jaguar, needs special equipment.’’
‘‘Right, but I know there’s something wrong. I just want a
‘best effort’ set-up I can work from. Anyhow, it’s already
less than 150.8mm from sub-frame to ground.’’
‘‘Ok, well if that’s what you want…’’

Anyhow, problem diagnosed, not alignment but camber angle
which was suspected (by me and you lot), but I didn’t much
want to hear.

AOL now offers free email to everyone. Find out more about what’s free
from AOL at AOL.com.

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

5

I recently replaced my power steering rack on my 89’ XJ-40.
Fairly simple job with no surprises…BUT…I forgot to make
any marks on my tie rods to reset the toe alignment. At first
I thought I’d just get it close and pay $90 to my most favorite
Jaguar lads to reset the toe. Then I decided HEY, if I can fix
all these things that go wrong on my car there must be some way
of accurately doing this myself !

I started with a very inexpensive laser level that shoots a laser
beam out of one end. This cost me about $18 at a discount tool
establishment. Next I made 2 small wooden stands that looked like
wooden ‘‘I’’ beams about 24’’ long and 6’’ high. The top of these
should be about an inch wider than the bottom. Now I was all ready
to go to work.

I took a 2x8’’ board six ft long and placed it exactly 8 ft forward
of the center of the front wheels (laying it on it’s edge). I took
a second board, same size, and placed it the same way exactly 8 ft
back from that same center mark of the front wheels (this puts it
just in front of the rear wheels.

Now I took my niffty little wooden stands and slid them up against
the front tires (car on the ground). The wider tops rest against
the tire walls and and the narrower bottoms miss the slight bulge
at the tires bottom.

Now place the laser level on your wooden stand up firmly against
the tire and mark on your boards where it hits. Flip the laser
level upside down and do it again to eliminate any error in your
cheap-O laser. the center between the two marks is your ‘‘true
mark’’. Do this on both sides, forward and back and when you
finally adjust the toe so the distance between the ‘‘true marks’’ on
the front and rear boards is the same you now have zero toe in and
out, which is in specs for my car.

Alright, at first this seems like a lot of trouble to save $90 …
but once you set it up it’s a breeze. Oh Yeah and you are also now
the proud owner of a cheap-o level!–
Groove
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

6

In reply to a message from Grooveman sent Sun 6 Sep 2009:

$90 at todays current rate is �54, which sounds expensive for wheel
alignment checking. a garage about 2 mile from me checks and
adjusts wheel alignment for �20 ( $32.00 ), so hardly worth the
trouble!
i d have to question the accuracy of d.i.y, but hats off to you for
the effort.
i d keep an eye on your tyres for a while for scrubbing , as a
pair of new front tyres will cost a bit more than $90!!!

regards–
The original message included these comments:

I thought I’d just get it close and pay $90 to my most favorite
Jaguar lads to reset the toe. Then I decided HEY, if I can fix
all these things that go wrong on my car there must be some way
of accurately doing this myself !

–
XJ40 1990 Sovereign 4.0 (RHD) UK
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

7

Hello,

Congratulations, I think that you can make quite a reliable tool. However, for what my experience is woth, 0°+ will eat the inner shoulders of the tires. I would give 1-1.5° toe-in, you will improve also self centering. Just see whether the car chases road imperfections and decide for yourself on the basis of feel and wear.

Yours,

Lluís----------------------------------------

To: xj40@jag-lovers.org
Subject: Re: [xj40] Front wheel alignment
From: xj40mark@hotmail.co.uk
Date: Mon, 7 Sep 2009 02:11:17 -0700

In reply to a message from Grooveman sent Sun 6 Sep 2009:

$90 at todays current rate is £54, which sounds expensive for wheel
alignment checking. a garage about 2 mile from me checks and
adjusts wheel alignment for £20 ( $32.00 ), so hardly worth the
trouble!
i d have to question the accuracy of d.i.y, but hats off to you for
the effort.
i d keep an eye on your tyres for a while for scrubbing , as a
pair of new front tyres will cost a bit more than $90!!!

regards

The original message included these comments:

I thought I’d just get it close and pay $90 to my most favorite
Jaguar lads to reset the toe. Then I decided HEY, if I can fix
all these things that go wrong on my car there must be some way
of accurately doing this myself !

–
XJ40 1990 Sovereign 4.0 (RHD) UK
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

Hay tantos ordenadores como personas. ¡Descubre ahora cuál eres tú!
http://www.quepceres.com/
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

8

In reply to a message from XJ40-MARK sent Mon 7 Sep 2009:

My experience has $90 cheap for an alignment on a Jaguar,
and most often, the shops get it wrong.

The only systems I’ve seen have all been 4 wheel laser based
systems and just getting the car onto the machine is going
to cost at least $90. Then they try to add in the special
‘‘tools and techniques’’ needed by a Jaguar and they’ll run
the price up even more.

I hate being lied to, I hate being gouged and I’m convinced
at least one of the two major suppliers of the alignment
systems has the Jaguar specs programed wrong so they never
get the toe correct anyway!

I’ve put together a large caliper type device using a length
of aluminum angle some adjustable squares and a couple clamps.

Adjust the camber to eliminate pull (increase camber on the
side that pulls) and then the toe using the measurements
between the rears and fronts of the wheels. Finally center
the steering wheel by adding and subtracting equal amounts
at the tie rods to maintain the toe adjustment.

Takes a few test drives between adjustments to get it right
but it’s well worth it.

I do like the laser idea, should simplify taking the toe
measurements.–
The original message included these comments:

$90 at todays current rate is �54, which sounds expensive for wheel
alignment checking. a garage about 2 mile from me checks and
adjusts wheel alignment for �20 ( $32.00 ), so hardly worth the
trouble!

–
91 XJ6, 93 Sov, 97 Sov – Driveway’s crowded!
Tampa Fl, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

9

In reply to a message from Grooveman sent Sun 6 Sep 2009:

Well, I certainly agree with Win that $90 for an alignment check is
as inexpensive as I could find. Hmmm … I wonder what the dealer
would charge, ‘‘Thanks sir, that’ll be … oh why don’t you just sign
over the title and we’ll call it even.’’

Actually if you do the setup and measurements carefully this is a
VERY accurate system. Doing the math you can set the toe at any
degree you want (a circle with an 8’ radius, X degree of toe equals
Y distance of circumference).

By the way if you finish getting your alignment just perfect but,
'ello Gov’nor, your steering wheel isn’t straight, exactly 1 turn
on your tie rod end (clockwise on one, counter clockwise on the
other) will rotate your steering wheel one and a half inches along
it’s outside circumference. I imagine you could just unbolt your
steering wheel and rotate it to a new spline but I think you could
start to run into turn signal cancellation issues.–
Groove
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

10

In reply to a message from Grooveman sent Sun 6 Sep 2009:

Do you ensure the cross member is at the correct height
150.8mm above the ground while doing this?
I came up with a similar scheme and simply added sacks of
sand I had to hand in the engine bay to get about 150mm. I
measured the diagonals lengths of the laser spots to get the
setup square then added a tiny bit of toe in. The workshop
manual states 0.8mm +/- 0.8mm.
I challenge anyone to measure 150.8mm above the ground,
0.8mm accurate from rough concrete or asphalt, come on
Jaguar. Do they still have such requirements on newer models?
Ah well, good fun for those of us who like doing it
ourselves and pretending we don’t trust anyone.–
89 xj40, new lease of life
Cheshire, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php –

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !