Tracking Gauge

[kjw911]

I would be interested in anyone has come up with a reasonably cheap but more importantly accurate home made tracking device. I have seen plenty of Dunlop gauges on ebay but they seem to go for quite high prices.

[falcemob]

Chalk marks on tyre and garage floor and a tape measure.

[tr7v8]

We've got a Gunsons Trakrite about £60 from various sources, brilliant piece of kit.

[GreenV8S]

Sticks and string work fine.

[Avocet]

Get 4 axle stands (or similar). Park the car on a flat floor and set an axle stand at each corner. Run length of cotton (or thin, strong string) round all 4 axle stands at wheel centre height to make a box round the car as close as possible to all the wheels without touching bodywork. Measure from the string to the centre of each wheel (ideally having taken the decorative centres out so you're measuring to metal). Adjust all the axle stands until the string is equidistant from the axle centre at each side of the car (and each end). Also get the strings down each side of the car equidistant from each other at each end. This can take absolutely AGES! Note that the front and rear axles may be a different "track" so the left and right rear wheel centres might be (say) 150mm from the string and the left and right front wheel centres might each be 145mm from the string. This doesn't matter.

You will now have a rectangle around the car with the longitudinal centreline of the car lying over the longitudinal centreline of the rectangle. You can now measure carefully from the string to the front and rear edge of each wheel rim and calculate toe in / out by simple trig.

I've used this method myself and other than taking a very long time to set up, it's pretty foolproof. I find I can measure to +/- 0.25mm with a six inch rule. It's not perfect but it's cheap! You can save a lot of time by haing two bats that go at the front and rear of the car with bits of string tied to each one. Tha tkeeps them the same distance apart at least, which saves a bit of setup time!

Also, if you can get an assistant and the underside of the vehicle isn't too low, a tape measure acros the tyre tread and check the difference in readings between the measurement at the front of the tyres and the back of the tyres cna give a rough indication.

[jwb]

www.beardmorebros.co.uk/website%20pages/how%20to/tracking.htm

This explains. An easy to make gauge.

However I do prefer the retangular string around the car method.

John