On the track to a top Triumph
Nigel gets his GT6 back on the straight and narrow
We’re all aware that correct alignment of the front wheels, or tracking, is critical to how a car steers and to the life of the tyres. Every manufacturer specifies wheel alignment, usually as a range which sets the front wheels either parallel or with a small amount of toe in, so the fronts of the tyres are pointing slightly inwards. The idea is that the tiny amount of toein means that when the car is moving forwards at speed, its rolling resistance loads the suspension bushes so the wheels can run parallel.
But we’re led to believe that checking and adjusting the tracking is a job that has to be left to experts with expensive professional kit. There are DIY methods involving string or wooden battens but I’ve always preferred using kit made specifically for the job. With the GT6 needing tracking adjustment after having the front suspension apart, I started thinking about how to check and set wheel alignment accurately on my own driveway. I figured that a bit of cash invested in a secondhand professional wheel alignment gauge could be repaid by avoiding the need to pay a local garage to do the job.
I could find used Dunlop alignment kits online for a few hundred pounds, but my search also found a tool called Trackace, costing under £80 and claiming to use a laser beam to set tracking accurately at home. To my mind, the words ‘laser’ and ‘accurate’ seem often to appear in the same sentence and the price tag was appealing, too.
Due diligence
Clicking on the Trackace website, I downloaded the instructions and tried to figure out how it worked. The kit consists of a battery-powered laser beam above a graduated scale and a mirror that, when leant against the front wheels, reflects the beam back onto the scale. The gauge has to first be ‘zeroed’ by reflecting the laser back from one front wheel. Then the alignment is measured by reflecting the laser back from the other wheel.
Reading this through and understanding the basic principles involved was enough to convince me that, in theory at least, using the Trackace I could achieve accurate wheel alignment
measurements. The only significant drawback I could see was that if the tracking needed adjusting, it couldn’t be done with the Trackace in place to measure the changes as the track rods were being turned. Adjustment has to be a process of trial and error, checking the tracking followed by adjustment and rechecking until the toe-in is correct. That means alignment adjustments using Trackace can be a bit more time-consuming than with professional kit. For this DIY mechanic, the benefits of being able to measure wheel alignment at home for an affordable price outweighed the extra time.
Try and try again
I ordered the Trackace and tried it out on my driveway. For the first attempt, I had to take my time, stopping to read the instructions, as I went through the steps to set up, zero the scale then read the toe-in. After a couple of times the process became second nature, getting quicker and easier. When I made a reading of the GT6 alignment, I could remove the Trackace and then go back, set up again from scratch and get exactly the same result. Obtaining repeatable readings gives me some confidence that the Trackace is indeed as accurate as it claims.
The graduated scale shows toe-in and toe-out in minutes, one minute being one 60th of a degree. Most classic workshop manuals specify toe-in as fractions of an inch or in millimetres, so it’s necessary to convert. This can be done with a bit of trigonometry but more conveniently, the Trackace instruction booklet includes conversion tables. For the GT6, the maximum 1/16in toe-in equates to about 16 minutes of arc.
With the GT6 parked on a flat and fairly level part of the driveway, my first check showed toe-in was in specification at five minutes, but I decided to try to set it closer to the mid-point of the 0-to- 16 minutes range. After less than half an hour of measuring, followed by adjusting the track rods then re-measuring, I got a reading of nine minutes, which is close to perfect. T
o prove the point, I went out for a test drive then measured again, getting the same result. I’m impressed. By the time I’ve used the Trackace on a couple more cars, it will have paid for itself.