Project Marina, DIY String Alignment

It’ll come as no surprise that I’ve paid for a lot of alignments in my time, and as on most cars they can only really adjust toe, it began to irk me how little value I got for my money.

With that in mind, there is one thing I have wanted to try for a long time but never really been bothered to do, as it seemed like too much work. A DIY string alignment.

I will say off the bat, I know it won’t be as accurate as frickin lasers on a machine worth tens of thousands of dollars, and adjusting the toe without a hoist is a pain, but for the cost of… almost free, it’s good enough.

I had done a lot of research and even considered spending the money on a pair of nice toe plates that you use with a pair of tape measures to check if the wheels are toed in or out, but the idea that it couldn’t identify if the wheels were “straight” but actually both pointed off to the same direction, didn’t sit well with me.

And then I found this guy’s video online, and it seemed just easy enough that even I could make a string alignment work

The basic theory is that you run a pair of string lines down the sides of the car. With certain measurements, you make the string lines parallel and then measure the distance of the front and rear edges of the wheels against the string to check toe. This method will only do toe, but that’s all I need to measure.

Having just done work on the steering of the Marina, and it being decades since it’s probably seen anything resembling an alignment, I wanted to check it before I went too far on the road again.

Years ago I marked the steering column before removing the steering wheel, and when I last refitted it I fitted it to the marks, which meant the wheel was off center for whatever reason (maybe wasn’t straight in the first place). I fixed this by just moving the wheel a few splines over, and it was close enough. Before checking the alignment now, I foolishly moved the steering wheel back to the marks, thinking it would be a good idea.

In an ideal world, you would center the rack, center the steering wheel and then do the alignment, but I don’t have a centering hole in the rack as the UK cars do, and I didn’t want to have to measure tie rods, so this is close enough.

I fired the car up, and using its freshly rebuilt clutch slave, moved it back up and down the driveway a few times to settle the suspension.

Before setting up, always roll the car forward, not backwards, as this can impact the alignment settings.

Next, I checked and set all the tire pressures to the same 28-29psi

Then I set up the string lines on my four axle stands. Almost immediately I noted that the string I was using wasn’t right, it was too thick and “fluffy”, you really need something like fishing line for this, so it’s thin and accurate. Regardless, all I needed was a ballpark figure, so I pushed on.

I pulled the string quite tight by rotating the axle stand

The first hurdle for me was that I don’t have center caps, just a big gaping hole. That makes it a bit harder to measure from the center, so after a few tries of different things, to set the string height I settled on my camber gauge with its top edge sitting at the center of the hub and the bubble flat. The height doesn’t have to be 100% accurate, just close enough to the same for both wheels on that side. The string height is set by moving the center of the stand up and down for coarse adjustment, and then sliding the string up and down on the stand for fine adjustment.

Next was to measure the distance from the center of the wheel to the string. You need to factor in the track width of the car with this, so that the strings are straight and not slightly tapering off, as the front and rear track are not usually the same.

In the Marinas case, the track is 1333.5mm in the front, and slightly narrower 1331mm in the rear. I wanted the string to be 80mm from the rear wheels, so I measured that from just in front of the center bore, at the height of the string.

Because the front is slightly wider, I needed to remove the extra width from my measurement, which is 2.5mm across both sides. Halve that, and you get 1.25mm per side. So I needed my string line to be 78.75mm from the wheel on the front. Moving the stands at the front and rear until I got those two measurements, on both sides of the car, and I finally had a pair of parallel strings. Not too hard!

Now it was time to measure the toe. I used my calipers on the wheel lip to check the distance to the string line. Protip, make sure your wheel weights aren’t in the way…

Having checked both sides, I knew the rear was square as the front and rear measurements were the same (good test of my string lines), but being a solid axle I expected that. The fronts, well…

The numbers were messing with my head a little, but from that I had 11mm of toe, but not in or out, they were pointing off to one side. They were pretty well parallel, but not straight. This is where the string line has an advantage over the toe plates, it can tell me the wheels are pointing off to the side but only had 1mm toe difference, the plates would tell me there was 1mm toe but not that they are pointing off to one side.

This was due to me moving the steering wheel on the splines. Darn.

I straightened the steering out so the wheels were more or less straight and then moved the steering wheel over on the splines to straighten that out. To settle the steering I had to push the car back and forth again, which meant the poor thing got its tail out in the rain. With the faint sounds of rust creeping in, I rolled the car forward and set up again. This time all I needed to do was set the string the pre-measured distance from the wheels again

Round two was a lot better, this time it looks like I’m slightly pointing off to one side

It appears I have about 1mm of toe in on one side, and I’m pointing off to one side still. I need to drive the car and see how centered the steering wheel is, I suspect it might need to go over one more spline, but since it hasn’t really stopped raining, I won’t be venturing out just yet. Once I have the steering wheel centered, and the car tracks straight, I’ll get some fishing line, set up again and see how the actual toe is. The setting in the book is 1.6mm combined or 0.8mm per side toe in (wheels closer together at the front edge than the rear).

Over all, the string method seems pretty good. It’ll suck to have to actually adjust anything since any time you move the car, move the strings or make any changes you need to set things up again, but you can probably get fairly quick at it with some practice.

I’ll play with it more, on my other cars too, as a quick basic way to make sure the toe isn’t wildly out before having someone check it properly on a machine (if needed). I wouldn’t bother with a machine alignment on this Marina, since there are no more adjustments than toe, and this isn’t a daily driver, as long as it’s in the ballpark and drives straight, I’m happy. My daily, or track car, should really be checked properly for handling and tyre life reasons.

I can definitely recommend giving it a go, it’s a fun skill to learn and pretty low cost if you have some measurement tools, a set of four jack stands (or similar things to tie the string to on each corner), some fishing line and some time.