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Rear Wheel Alignment
PeterV - 3/10/11 at 11:02 AM

The WLR has spent two happy weeks at Abbott Racing being hung and fettled. All the corner weights have been taken and the suspension set up along with cambers and casters (or at the very least they have been measured) and adjusted. The car now feels a lot better both in handling performance and build confidence after having them that know paw through it.

But the big problem is with the rear end which has a massive 11mm toe in on each side. Yikes!!

Before I go mad stripping everything down I thought I ask if anyone has had a similar cock up and knows what I’ve done wrong or has a sensible way of sorting this kind of problem

Nick DV - 3/10/11 at 11:14 AM

Do you really have a problem? You say that everything is better, and whilst I would say 11mm is massive - are you sure that figure is correct - would Abbott Racing have made such a big error.

Before you start changing/removing things, it would be best and possibly a money saving exercise, to just phone them and ask.

Cheers, Nick

PeterV - 3/10/11 at 11:22 AM

Yep Abbott gave me the figures and its 2.75 degrees toe in on the rear. With no adjustment mechanism they were not inclined to remanufacture anything without my input. So I have the car back in my workshop ready for something….. if only I knew what

snapper - 3/10/11 at 12:08 PM

You can add caster and camber wedges between the hub and the upright.
Use washers between the hub and the upright face to reset the toe, caster, camber, measure the thickness and then have a plate milled to the correct profile.

Nick DV - 3/10/11 at 12:39 PM

quote:
Originally posted by PeterV
Yep Abbott gave me the figures and its 2.75 degrees toe in on the rear. With no adjustment mechanism they were not inclined to remanufacture anything without my input. So I have the car back in my workshop ready for something….. if only I knew what


I understand what you are saying now!! Do you not have any spec or data sheet for the car that you can refer to, or do you not know anyone else/other forums with the same car?
There are others on here that are clever enough to answer this, and I'm sure the'll be along at some stage to give an answer. Good luck

Cheers, Nick

PeterV - 3/10/11 at 12:41 PM

quote:
Originally posted by snapper
You can add caster and camber wedges between the hub and the upright.
Use washers between the hub and the upright face to reset the toe, caster, camber, measure the thickness and then have a plate milled to the correct profile.


Cheers, that sounds like a plan. Was thinking of some form of shims but a plate sounds like a much better idea. It just so happens I have a new Warco mill on order so by the time it gets here it could be its first test job. I mean you have to test it before using it on real customers work don't ya

procomp - 3/10/11 at 02:04 PM

Hi

It's not an uncommon problem with that design ( MK ) It's purely down to either inaccuracies in the jigging of the chassis or wishbones, usually the chassis brackets.

Best solution would be to add an adjuster in to the rear leg of the wishbone as per Mac#1 did with there MK copy.
Or continue as described above adding shims Etc. Personally i would use shims to start with to get everything aligned and run a few hundred test miles to confirm the settings are correct then machine up some plates.

For shims don't use washers as the adjustments that are required to fine tune are small. Use shim steel made washers try 4 or 5 tho thick items.

Also don't forget to get the thrust alignment sorted also not just the overall alignment.

Cheers Matt

PeterV - 3/10/11 at 02:27 PM

Cheers Mat.
I suspect chassis jig error coz it is perfectly wrong on both sides. I'm guessing that the wishbones would be opersite errors, unless of course I mounted one upside down.
Anyone got any pics of the Mac#1 design rear wishbones?

britishtrident - 4/10/11 at 08:10 PM

What happens if you switch the wishbones left to right without flipping them ?

PeterV - 4/10/11 at 08:39 PM

quote:
Originally posted by britishtrident
What happens if you switch the wishbones left to right without flipping them ?

According to my stick of inches not much. I know my stick is not totally accurate but the other thing is the book of words, on building, show the wish bone brace strut running rear to front and that's how my ones are. The only way to achieve this would be to flip the wishbones when transferring them. Maybe the book of words is wrong though?