Camber and spacers

 This is another of those jobs that started as a five minute fix and has escalated into something much bigger. Essentially I want to get rid of this;

The 'stack of washers' is on the rear suspension and is used to adjust camber. It's a pretty simple process, add washers to increase camber, remove them to decrease it. However I'm not going to be taking this on a track and chase lap times so there's no need to change it frequently. So I want to replace it with something a bit more stable. 

The mechanism will still stay as is, but what I want to do is reduce the leverage imposed on the bolt. It's probably overkill (and the 'unsprung weight' addicts will hang me out to dry!!) but I want to increase the surface area of the join between the two plates. There's no benefit to going larger than the smallest side (upper in the photo) so I'll make a spacer to suit that size.

The main issue is material, and this is where the worms started pouring out of the can. The current gap is 18mm, but I have no stock that thick. I can't use tube because it wouldn't be any better than the washers, and buying stock without the ability to machine to the correct size is a bit pointless. The biggest I have is 5mm plate, but of course 18 doesn't divide by 5 so I'd need something else as well.

Or would I? Now, I've not measured camber for a while, and now the fuel tank is 95% full it's a bit heavier on the back. So on the weekend I measured the camber front and rear;

• Front left -4.3 degrees
• Front right -1.9 degrees
• Rear left -3.7 degrees
• Rear right -4.2 degrees

First thing that jumps out is the front left, that's way too negative. That needs the upper adjustment to be opened up one turn. Of course, doing that I'll need to reset tracking AGAIN! 

The rears are far too negative as well, I'd prefer -1 or maybe even zero. The difference between sides isn't too bad so I can do the same process for both. 

But what is the process? Well, I simply need to round up! Given that I wouldn't have been able to make an 18mm spacer I have to use either 15mm (3 plates) or 20mm (4 plates). I'm not sure what that extra 2mm will give me, but it won't be enough to push it past zero. Best guess I'll end up with about -2 both sides which would be fine. 

So I need eight plates made up, which I'll then test fit to check, but ultimately weld up in a single block. That will ensure the bolt is only loaded with shear forces rather than bending forces. As suggested I'm sure Mr Champion will be turning in his grave when I add a seemingly innocuous block of weight, but at least it won't be coming off anytime soon. 

Just one last note, the possibility of rotation and unscrewing. It had occurred to me that tiny movements in the bushes on both sides 'could' allow the nut and bolt to unscrew. But the top wishbone isn't subjected to twisting movements which discounts that side straight away. The upright is subjected to significant twisting movements by braking, but that rotation is turned into linear motion when it gets to the upper wishbones (well, it's linear in two directions but the wishbone allows movement up and down). Obviously I'll keep a check on things but with various areas of friction, a really tight bolt and a nyloc nut I can't imagine this going anywhere. Even if somehow it gets loose it would still function as a wishbone. It would have to come all the way off (or snap), and of course the same could then be true of any other bolt or weld on the chassis. 

Over the weekend I cut a length of steel to 45mm wide, enough for eight plates. Hopefully at lunchtime I'll cut it into 65mm sections then drill through the centre of all of them. To keep them in line when welding I'll simply use a spare bolt to secure them straight.