bottom suspension bracket shims

[TWF]

Hi ,today i stripped the N/S suspension off my SP,I had to remove the bottom brackets from the chassis because the nuts had been rounded in a previous attempt by someone else ,the brackets had shims behind them, are the shims necessary and are they available , as the ones i removed removed just disintegrated ,Regards ,Terry .

[Vortex O'Plinth]

The shims are there to set the correct wheel camber. These available on ebay are modified to make fitting possible without removing the bracket. You will need to calculate the thickness required to achieve the desired camber.

[Ian Slade]

Playing about with these shims can seriouly affect the lightness or heaviness of the steering, the car was originally set up for positive camber but going to negative camber can improve road holding.

[silverdart]

I understand that they are there to adjust the castor angle. I would like to lighten the steering on my car so what should I adjust?

Dave.

[Vortex O'Plinth]

I understand that they are there to adjust the castor angle. I would like to lighten the steering on my car so what should I adjust?

The shims are there to set the camber not the castor angle. Daimler made no provision for castor adjustment on the SP.

When adjusting camber the shim thickness under the two brackets should be the same, but by keeping the total thickness of the two shim packs constant but changing the distribution between the brackets the camber will remain practically constant but there will be a small change in castor. This is so small as to have very little effect on steering effort.

The car was originally designed to use cross-ply tyres and given 2° of positive camber. Most owners now fit radials and these will benefit from a reduction in camber. Also - as Ian points out - a degree of negative camber can improve roadholding.

[Ian Slade]

The only way to change the castor angle is to pivot the vertival link either forward or backwards at the bottom wishbones which will involve some more than basic engineering, changing the car to negative camber will alter the Akerman angle which will affect the steering weight.

[TWF]

Hi ,when i removed the lower wishbone brackets from my SP,the n/side had one(1) shim behind each bracket but the O/side had four (4) shims behind each bracket ,is this normal as the brackets did not appear to have been removed previously , Regards Terry .

[daimlersteve]

The need for shims is governed by how straight/ org. the chassis and vtl. links are . If a turret is twisted or bent out /in there can be a lot of shims/packers needed to bring back even to std settings . If there is not a degree of experience in setting this up i suggest re-assembling the lower arms with 5mm of packers / (penny washers will to to setup) behind each , blocking the lower arms to ride ht. and removing shims to give the wheel/hub 0 deg. camber ( vertical at rd. ht. ) . Then take it to a good wheel alignment firm to check it over and adjust . Castor could be anything from 0 to 2 degrees if you're lucky.
Steve

[Ian Hastings]

Regarding camber angle does anybody, who is good at sums, know what thickness of shim for the lower wishbone is required per degree of camber?

[Brian-H]

Regarding camber angle does anybody, who is good at sums, know what thickness of shim for the lower wishbone is required per degree of camber?

You can't really say "per degree" although for the first degree of a right-angled triangle you can say "per minute" (which is a 60th of a degree).
Use this link http://www.carbidedepot.com/formulas-trigright.asp

It's side "a" that you want, with angle A being the angle, and side "b" being the length (note that for less than 1 degree, sides "b" and "c" are almost the same length)

e.g.
with "b" = 1000 and angle A being 1.0 (60 minutes), side "a" = 17.45
with "b" = 1000 and angle A being 0.5 (30 minutes), side "a" = 8.72

In other words, for 1000 mm, and for a deflection of 1 degree, you need 17.45 mm, and for a deflection of half a degree, you need 8.72 mm.