Some useful setup tools which you can make FREE from bits & pieces lying around the workshop!
Camber checking gauge
The first is a camber gauge – it’s dead simple to make. Just take a look at the pics below, if you want to enlarge, just click on them. Ok, the gauge just happens to be sitting on a genuine Indy car tub previously raced by Ryan Hunter-Reay, but don’t worry you won’t need one of those! This gauge is made from a single piece of 2.0mm aluminium sheet, you could use down to around 1.5mm or up to maybe 3.0mm, it can be aluminium or steel or even rigid plastic, though you’d need to make a minor change to how the string locates at the top of the gauge (RHS of the pictures) as plastic won’t make a permanent bend as the ali or steel will.
The stubs which stick out at each side should be set at such a size that they will comfortably fit against the wheel rim of the size of wheel you are going to be using it on, without touching the tyre which would interfere with the measurements – this one will “do” wheel sizes from around 15″ up to 18″, but you can make the gauge for any size of wheel you want. At the top of the gauge (RHS of pics) there is a tab at the exact centre of the sheet, bent at 90 degrees & drilled dead centre to accept a piece of string the end of which you then attach a weight to. The lines for degrees are made using a normal protractor – if you don’t have one search your kids school bag – but don’t blame me for anything else you might find!
Make degree markings at whatever spacing you need depending on the accuracy you are trying to achieve. We marked this one at 5 degree intervals & then added the 2.5 degree markings simply by adding a point half way between the 5 degree marks. The gauge is pretty accurate, you can clearly see from the pic left above that this wheel has just under 1 degree of negative camber. When using the gauge make sure it is passing through the dead centre of the wheel as in the pic to the right above & is as near vertical you can get without interfering with the movement of the weight, you’d probably want something more accurate if you’re racing, but for road use it’s more than sufficient!
Simple Tracking Check Bar
Another simple to make tool, I actually used the legs from a kids trampoline (fortunately the neighbours haven’t found who took the legs off their trampoline as yet!) & inserted them into a piece of 25mm square tube which I had previously drilled & welded a couple of nuts to I then made some “wing bolts” by welding a tab across the top of each bolt see the pics below
The accuracy of this gauge does rely on the inside walls of your tyres having no significant runout, with modern wheels & tyres this should be virtually nil, if you find you have significant runout then this needs investigation before taking any measurements or making adjustments. You simply place the 2 flat ends of the bar against the inside wall of the tyres & adjust the width until it is a comfortable tight fit between the inner walls of the 2 front tyres, first at the rear end of the tyre & then at the front & compare the 2 readings.
You don’t need to have any markings on the gauge as such, though you could easily add these if you wish, if it is a comfortable fit at the rear of the tyres, but won’t go in at the front then you have toe-in, if it is a comfortable fit at the rear, but a slack fit at the front then you have toe-out. Obviously bear in mind you are not going to be measuring at the wheel centre, so be aware of this when making measurements. I find probably the most accurate way to check is to get a comfortable fit at both front & rear of the wheel so you know at that point you have zero toe. Then roll car back a few feet & recheck, do this several times for differing distance & rolling both fore & aft, you should find the readings are consistent, assuming this to be the case then looking at the pitch of the thread & the positioning of the track rod end relative to the wheel rim it is fairly simple to work out the approx no. of threads or part turns to set the tracking correctly – this can then be very simply checked with the gauge to confirm correct. It’s never going to be deadly accurate, however in the 30 odd years I’ve worked on road & race cars I found that sticking to manufacturers settings almost invariably resulted in excessive & uneven tyre wear & the best result was achieved by monitoring tyre wear & adjust tracking accordingly. Sometimes if the best handling is required a sacrifice has to be made in terms of tyre wear.
If you want to make the gauge more traditional & more accurate then you simply need to add a “step” or “dog leg” to each end of the bar with a flat end on it such that you can get the bar underneath the front of the car & get the end of the bar to the centre of the wheel height on the wheel rim