Caster and Camber Shims

[RobinB5]

Had a 4 wheel alignment check done today at a local place that came highly recommended. At least one parameter is in-spec (rear toe total)

Expected values are a little off compared to the service notes, but service note values will take precedence.

Anyone know what KPI and Include angle represent? Can't find any reference to them in the service notes so a bit surprised to see expected values there.

The car tends to steer left easier than right, do any of the above values reflect that behaviour?

I'm going to order various shims from SJs then give them to the garage to do the actual alignment changes. From the service notes I should be able to work out what castor and camber shims changes are required (castor: 1.5mm shim transference will alter by 0.4deg, camber: 1mm change in hole position will alter by 0.4deg). To do that though it looks like I have to disassemble the front top wishbones, count and measure the castor shim plates and also  measure the camber plates.  Is this correct? Although it looks like either the castor shim washers on the inboard side can be changed OR the castor shim plates on the outboard side can be changed, I'm assuming it'd be easier for them just to adjust the outboard shim plates? Anything else I should watch out for / prepare for?

[drdoom]

KPI is King Pin Inclination, a projected axis representing the line through upper and lower balljoints, as viewed North-South. As the upper control arms are slotted where balljoints attach, this may be varied. As I read the printout you might pull in the left upper balljoint a touch to balance L-R camber while eliminating the KPI side-side differential, though I doubt you'd find the change perceptible. More significantly you'd want to reduce the excessive toe figures up front as these are contrary to good steering response and effort levels. Aft end looks good as is.

Cheers 

[RobinB5]

Thanks @drdoom. I wonder where the expected values came from? 

[RobinB5]

I've been seeing what castor and camber shim plates are currently in situ to figure out what to order from SJ to give to the garage to make the required adjustments.

On the nearside front, the castor has to be increased by about 0.4deg. This requires a 1.5mm thick shim plate to be transferred over to the lhs of the ball joint:

 

This would leave no shim plate on the rhs of the ball joint. Is this advisable or should the castor adjustment be made using washers on the inboard end of the wishbone?

[sailorbob]

There is no problem in having all the shim plates on one side of the ball joint.

It is the inboard side where you need to watch any shim washer adjustments as a minimum of 5 mm clearance between the top wishbone and the chassis is required.

[RobinB5]

Thanks @sailorbob! Good news is that no new castor shim plates are required, just a shuffling round on both sides. Have had to order a pair of camber shim plates though from SJ to get the nearside camber adjusted. I'll provide the service notes and proposed changes to the garage. Just wanted to ensure they used proper bits and bobs. Biggest noticeable difference no doubt will be the Toe though.

[RobinB5]

Did the front castor and camber shim stuff myself, had a garage do the Toe today. Just been for a spin. As many others have reported, getting the settings correct after they've drifted is like a driving a new (and much better) car. She's planted going round corners in a way that she wasn't before. Loving it, money well spent.