I went to have my 2006 XK8 aligned when having my tires balanced at my local tire shop, and was told the Right Rear Camber is out of specifications.
Actual was -1.0; spec is -0.9 to -0.1. And it is wearing more on the inside edge of the Right Rear Tire, so I would like to have it adjusted.
Alignment guy told me it requires (expensive?) shims from Jaguar and he did not seem real keen to get them ordered.
It wasn't clear if you get them individually or if there are different thicknesses of shims or if they come in a package (he mentioned a shim pack).
He showed me that they go into the rear axle at the joint where the shaft out of the differential bolts to the axle going out to the hub.

Anyway, can one of you knowledgeable people tell me about these shims?
Is there a Jaguar part number for them?
And do you know from doing this what it would take to adjust mine to get it in the middle of the spec range (assuming that is where it really should be)?\
That way I could order the proper shim(s) without trial-and-error (expensive if you buy them individually without knowing what to order).

Other cars I have seen had charts that told you "if you are at x and want to get to y, add this much ..." But that useful information is not in the Jaguar service manual.

Any other advice or enlightenment welcome.
Thank you,
John

 

I have heard of shimming the rear end to get the alignment within spec, however I have never done this personally.

I'll be staying tuned to hear more about this, I'm sure someone here has been down that road.

 

I will have to check this as it is off the top off my head but I believe every 3mm alters the camber by .5*, Jaguar supply the shims in .5mm increments but a lot of the thinner ones are no longer available, the ironic thing is the thickest shim (8mm) is the cheapest at about $10 but you will need someone with a lathe to face it to size which puts the price up.....

 

Every shim from the factory that I removed to set camber was 4mm.

Our dealer parts dept kept 7mm in stock and it set the camber within specs 99% of the time.

Just my observation.

bob gauff

 

SNG Barratt catalog lists the following under "Half shaft spacer":
3.5mm CBC480635 A/R (as required)
4.0mm CBC480640 A/R
4.5mm CBC480645 A/R
5.0mm CBC480650 A/R
5.5mm CBC480655 A/R
6.0mm CBC480660 A/R
6.5mm CBC480665 A/R
7.0mm CBC480670 A/R
7.5mm CBC480675 A/R

From prior comments, I need to get a 3 MM or a 7 MM spacer.
Per XKRacer's comment, 3 mm would get me 0.5 degrees which would put right in the middle of the range.
Motorman - was your experience that you typically removed a 4 MM and installed a 7 MM (for a 3 MM increase) or that you went from nothing (no spacers) to a 7 MM one?
I don't think I saw a shim in my car at all when it was up on the hoist.
I am following up on this because at over $50 per spacer, I don't want to order the wrong one.
Thanks to both of you for for your expertise.
John

 

What pressures are you running in your rear tires? Trial-and-error has taught me that on my wife's 2006 XK8 Victory Edition convertible running 255/40/19 rear tires, anything higher than 30 psi will cause the rear tires to prematurely wear right down the center. Her two front tires (245/40/19) do just fine between 32 and 34 psi, though....

 

Thanks for the suggestion to check the tire pressures.
The car is new to me so lowering them a bit now will likely save me finding out that 32-34 will wear them a little too fast in the center.
But the Right Rear Tire is definitely wearing more on the inside edge than the outside edge which is an indication that the camber is out of alignment (along with the readings from the mechanic's fancy Bear Alignment System).
And I will check the pressures!
Thank you,
John

 

I removed the 4.0mm Factory Spacers and installed the 7.5mm units when I installed the Mina Rear Lowering Springs. Camber is now in spec.

There are small "Ears" on the Half-Shaft Flange and the Differential Flange that Center the Flanges on the Spacer. It is not recommended that the Spacer Pack be made up of thinner Spacers Stacked together, although some have done that without problems.

 

I'm no expert, but in reading the many posts on the forum about alignment, and with my own experience, I think your issue might be toe out rather than camber. My camber is -1.5 and -1.2 on the rear, but I experience no wear. Too much toe out will wear the inside edge like you are experiencing. You don't write what your toe was before alignment, but I suspect that it was toe'd out. Search the forum for posts from Brutal regarding alignment, you will find a lot of great information.

 

Theyre full of crap imo. First youre .1, barely out. If i blew too hard on the tire it would be in. And thats not enough to cause inside tire wear till you reach 2*+/-.
I wouldn't do a damn thing, and like steve said, if toe is to toe'd out that will wear the inside, not that little bit of negative camber. Most of the older jags i align are slightly out in the rear and never ever have an issue. And then usually when the camber goes close to -2* its because they hit something and or the springs have gotten too weak(low ride height) and or upper shock bushings collapsed just like the fronts do. Peace out time to go vote in the primaries

 

-1 isn't that bad indeed, not something I would change.

But if you would, then a 4.5mm shim (instead of the 4mm) will bring you already closer to about -0.8. I always use the following to determine the best shim: 0.5mm is about 0.19 degrees decimal. This varies a little pending on the toe setting as that bolt also determines again the camber, so a 5mm shim will put you definitely closest to the nominal setting of about -0.7


Don't forget to make the measurements with a full tank!

 

If you had a Porche you would have -2* in the rear and the outside edge of the rear tires doesnt touch the ground resting. But throw it into a corner and it sticks like on rails. Of course it always depends on suspension design and amount of camber gain when cornering

 

As above, I am not concerned by moderate negative camber for reasons of tire wear.

However, I dislike it for the saggy butt effect ... don't like saggy butts

 

The Right Rear Toe before alignment was 0.33 degrees and after alignment is 0.18 degrees. I have uploaded a PDF showing before and after values for each alignment value as well as a before PDF that is more pictorial in nature.

As to the calculation of how much shim to add to adjust Rear Camber.
My actual is -1.0; the range is -0.9 to -0.1 so middle of the range would be -0.5. Wouldn't the ideal be exactly in the middle?
So ideal is to move my camber 0.5 degrees.
Or is -0.7 better for some reason?

Avos - if 0.5 MM is 0.19 degrees, then 0.5 degrees requires 1.32 MM which is smaller than any shims available. I don't remember (quick glance) seeing a shim in the half-shaft joint currently.

So perhaps I am overly concerned with Rear Camber.

From your experience, would the Toe values account for wear on the inside edge of the Right Rear Tire? Are the adjustments made going to be sufficient to solve this (it is now within spec).
Thanks to all for the insights and explanations.

 

No one commented after I posted my toe-in/out figures so not sure what to do next.
I am not in good position to argue with alignment people about the fact it is out of spec and it would make me feel better to be within.
Any of you happen to have an old used shim around 4.0 MM +- 0.5 MM sitting around?
PM or email me an offer orif truly surplus, I would gladly pay the postage.
Thank you,
John

 

Sorry forgot to react.

There is only 1 bolt to adjust the camber and toe, so pending on how sits today you could get a slightly different result on the camber (and toe) once you added shims (and remember the fuel level). I wouldn't add a shim, just buy the correct size from Jaguar (i.e. either the 4.5 or the 5mm as suggested, better the 5 imo).

I can see that you would have more inner tire wear with too much toe in (and too much camber), but have never experienced that as I always try to keep my setup aligned.

 

I would not worry about the camber, have a look at my rear results, both have too much camber but are in spec on toe, I had new tyres put on 18months ago and have put on 15,000 miles. I have no trace of excessive wear on either edge, just too much wear in the middle which I spotted after a year and have reduced the pressures a bit to try to fix.

 

What did you drop your rear tire pressures to after noticing your center wear to be excessive? Not knowing about the excessive center wear tendency when we purchased the XK8 in February 2012, I started all four tires at 33 to 34 psi. By late 2012 I dropped the rears to 31 psi. By early 2013 I dropped the rears again to 30 psi. Now, I don't get concerned as long as the rears don't drop below 29 psi....

The fronts have continued to do just fine at 33 to 34 psi....

 

I took the backs down by 2psi from the spec value for 19inch wheels.

 

https://www.jaguarforums.com/forum/a...0210-final-pdf

Several things on this from my perspective.
1, yes that toe out right rear would definitly cause inside tire wear, not camber
2, i dont like the front toe specs being in the middle because as you drive it pushes out. On your year car mileage etc i can almost bet money that it will toe out too much as you drive. If i aligned i would have brought to the inside of toe in spec front
.18-.21 maybe even in the red toed in depending on how much the settings move when pushing out on the inside of front tires while aligning to simulate what your suspension is going to do driving not sitting on the rack. Aka mercedes benz pressor bar. Everything else looks fine