Track measurement tool

[Troll Hunter]

Fed up with trying to read a tape measure while holding both ends to check the tracking on my Defender, while lying beneath it, I made up the tool in the attached file. This allows me to concentrate on one thing at a time. I can adjust the tool length using a small screw driver, until I get it to the exact distance between my wheel rim edges, one full turn giving 1mm change in length. I can then get out from beneath the beast to measure the tool length, and concentrate on getting an accurate measurement, without worrying that there will be any change in length of the tool. I am finding that this gives me good repeatability and is far easier than trying to read the tape measure when it is bent where it touches the wheel rim.

Track measurement tool.pdf

Mike

[duncmc]

Similarly, last time I did this a feww weeks ago I just used a piece of wood cut to roughly the right length. Then I just used my steel rule to measure the gap between the end of the wood and the wheel. The actual length doesn't matter, just the difference between the front and back.

Thing is I still needed to get out from underneath each time to push the car back and forwards to settle the adjustments made to the tracking before measuring again.

[Giles]

I use an old car aerial (and tape measure!) to measure the distances; you know, one of those multi-stage pull-up push-in ones: the perfect tool

[Anderzander]

I have an old sprung steel shower curtain rail - it holds itself in place whilst I mark where the extending section slides in to with a felt tip. Do the same measurement off the front of the wheels - divide the distance in half and work to that.

[miketomcat]

My dad has a tool that is a steel tube with uprights on either end wider than the truck and high enough to reach the center of the wheel. At one end you have a fixed pointer that points inwards to touch the rim. At the other end you have an adjustable pointer. Set up in position on one side then drop the fixed pointer into the wheel giving you enough length to clear the tyre on the otherside thus you can remove without altering it. Do the reverse to get it on the otherside of the wheel and adjust as necessary.

Mike

[Dave W]

I do mine slightly differently, I run a piece of thin wire around all 4 wheels at hub height, tensioned between the two rear wheels with a bungee. You can quickly see where the tracking and steering position is by the gaps between the tyre and the wire at the front and rear of each tyre. If both front tyres are touching the wire at the front and rear than you are at 0 toe out, adjust it until both front tyres have an appropriate gap to the wire at both sides, turning the steering to centre it as needed. You can also get the steering central position and adjustment of the drag link at the same time.

It's not perfect but given the variability of tracking on a Defender with steering it's always worked pretty well for me, I often do it with the front axle on axle stands and not noticed much if any difference between the tracking when raised and when "settled" on the ground. Having had it put on a laser setup afterwards it was out but not by enough to warrant adjustment.

[Snagger]

I used one of those extending red and grey plastic mop handles (Vileda, I think) from Tesco, with marks made on the telescoping section.

[mmgemini]

I use an old car aerial (and tape measure!) to measure the distances; you know, one of those multi-stage pull-up push-in ones: the perfect tool

The Ford rally car team used to use one of those on rallys when servicing

[Troll Hunter]

I found that all these sliding antenna or adjustable mop handle systems have a major drawback in that trying to measure accurately - to better than 1 mm - is almost impossible unless the antenna or mop handle is calibrated. My chances of removing the antenna from between the wheels and getting it to where a tape can be reliably used, without any movement of the sliding sections, is almost nil. I came to this conclusion after achieving zero repeatability of measurements! Hence my threaded option, which allows me to get out from beneath the vehicle and take measurements on the bench with no danger of the gauge rod having been changed.

Mike