Hi Guys

So recently lowered my 2000 XKR on new bilsteins and H&R springs paired with new wayne tate strut mounts. After driving and letting the suspension settle, took it in for an alignment in order to get everything dialed in including figuring out which shims to order to get the rear camber in spec . The rear camber is -1.54 (L) and -2.36 (R) and per my research "0.5mm of shim per 0.2 (positive) degrees"

Part #: C16621 .46 MM Shim
Part #: CBC480635 3.5 MM Shim
Part #: CBC480675 7.5 MM Shim




Now, if my calculations are right, I need x1 3.5mm for the left and x5 0.46 for the right

Right?

Thanks

 

When I worked at the dealer and performed suspension alignments, I never found anything but 4mm from the factory.

The parts dept kept 6mm shims and that seemed a common part to replace the 4mm to get an older car (over 50K miles) back in spec.

The MAX is about 8mm before you run out of 'bolt-length' on the output flange.

I guess you are wanting to 'stack' the original with additional shims?

The thickest OEM is 7.5mm if I remember correctly.

 

SNG Barratt's carries them in various thicknesses from 3.5mm to 7.5mm -called halfshaft spacer

https://www.sngbarratt.com/English/#...assembly/29985

 

Yes but its been pointed out that SNG lists them in all sizes so thats great!

Thank You!

So just to verify my calculations are correct, ill need x1 3.5mm for the left and x1 2mm for the right

Correct?

 

Hashim,
Just to confirm that your research is about right but the spacer calcs may be wrong.
did the math (high-school Trigonometry!) and the actual Camber change for 0.5mm spacer is 0.22 Degrees.
Now be careful that Angle 0.22 is a Decimal number and your wheel alignment readings are in Degrees/Minutes/Seconds so 0.22 = 0"13' Angle minutes

Based on the above calc, to adjust the whole amounts on the report is as follows. But these differ a lot from your calcs and now I'm not 100% confident.

Can anyone else concur ?
To be 100% accurate, we need the Hub centers dimension. This is called 'Hyp in above calc and I used 130mm - which was a poor measurement with a ruler....

 

Don't know about calculations but many threads in the forum that discussed lowering the rear recommend changing out to a 7mm or 7.5mm to bring rear alignment into spec. I'd say try by the calculated values - worst thing that could happen is you have to order bigger shims

 

To throw another set in - my calc is an additional 3.5mm on the left and 5.25mm right, based on 0.2° per 5mm and setting to the mid-point of the spec.

mid spec = (-0°54' + (-0°06'))/2 = -0°30'

Left -1° 54' - correction 1°24' (1.4°)

Right -2°36' - correction 2°06' (2.1°)

Might be tight getting the RHS in-spec

 

michaelh,
Agreed. The mid-point of the spec is a much better target as it allows for measurement error and shim availability....

 

I think the last time I did any trig, sin cos & tan were kept in tables in a little brown book...

This thread is also a useful indication of what happens when the rear springs start to sag, as motorcarman alludes to above.

 

Hi Guys and Gals,
I came across this thread after lowering my 2003 XKR Convert, with Adamesh coils front and back. The car has 186 K miles, but runs like a top. Car looks great and handling is much improved, but I need shims and a 4 wheel alignment. The guys at Wheel Works said the shim computation and install are above their pay grade.
I appreciated their honesty and don't want to have to install one size shim and then remove and replace them thru trial and error.
Based on these numbers from the attached alignment read out photo, what size shim would get me in the ballpark for the rear alignment? I've read in this thread about 6mm or maybe 7 or 7.5mm shims probably being what's needed?
Like I said, doesn't have to be perfect, but good ballpark advice would be greatly appreciated.
Evan

 

When performing an alignment, TRIAL AND ERROR is what was done to accomplish the task!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

We did not just throw a bunch of shims at the car and walk away!!!!!!!!!!!!!!!!!!!!!!!!
Sometimes trial and error was the way it was done.

I guess if someone can't poke a touchscreen and move some words around on a computer, then it is TOO HARD to work on and just tell the customer 'I CAN'T HELP YOU'???????????????????WTF????????????????

 

You need to follow this formula "0.5mm of shim per 0.2 (positive) degrees"

Put down -2.3 degrees on a paper and keep deducting 0.2 until you get within spec. How many times did you deduct? lets say 5....5 x 0.5 = 2.5

You will need 2.5mm shim on top of your factory 4mm

Here is mines after H&R springs, 7mm and 9mm

 

Thanks Hashim!

 

ET1,

As motorcarmen says, there is trial and error involved in getting this right but hopefully the calcs below will help you select the right spacers to purchase. Also, as Michaelh says, we recommend you consider target to the mid-point of the spec. Your actual rear Camber measurements (Both - 2.2 Degrees) are approx. 1.7 Degrees from mid-point. Target Camber spec range is - 0.9 - 0.1 Degrees (Mid-point -0.5 Degrees).

Luckily, your alignment readings are in decimal Degrees which makes calcs easy 😊

So;

For maximum Camber (-0.9 deg), Additional Spacer = 130 Sin 1.3 = Additional Spacer = 2.95mm

For mid-point Camber (-0.5 deg), Additional Spacer = 130 Sin 1.7 = Additional Spacer = 3.86mm

For minimum Camber* (-0.1 deg), Additional Spacer = 130 Sin 2.1 = Additional Spacer = 4.76mm

*Note; Be mindful that minimum Camber set-up on a lowered XKR running 10J wheels will reduce tyre-to-arch clearance when suspension is bottoming out.

 

That's what I was hoping when I bought the 7.5mm shims to get my H&R lowered XK8 in range, but unfortunately they were still not enough. I couldn't find thicker shims, so I ended up buying a 5mm shim and added it to my oem 4mm shim to get me to the 9mm I needed. Admittedly, I was advised against doubling the shims, but I couldn't find any factual data on any risk... and, so far, no issues.

 

Thanks PK, this forum is the best!

 

Yes, it is!