Alignment DIY

[Dynjo]

I have been developing a home-brew technique for measuring the various alignment parameters and I think its finally good enough to share. It requires the purchase of a few special tools, but they're not too expensive, and of course, they can be used over and over.

Your comments and suggestions would be appreciated.

The first step is the easiest, but requires the most expensive tool. Shown here is a typical caster/camber bubble-type tool, available from any of the racer supply shops ($200-$300). Mine is really old. You can see that I had to extend its length by bolting on a piece of aluminum angle (18" wheels were unheard of 25 years ago when I bought it).

Now, I bet you can do the same thing with one of the new, digital levels you can get at any of the big-box hardware stores, but that's a different story.

Oh, and thanks to the Blue Man Group for lending me a hand this day...

Here you see one Toe Plate leaning against a tire/wheel. These are also available at the race car shops (about $60). The plates have little slots at each end to capture a tape measure. One tape measure passes in front of the tire and one passes behind the tire.

Here you see how the tapes have come across to the other side of the vehicle. The difference between the readings is "Total Toe".

For best results, you need good light and need to tension both tapes equally. It takes a little practice and a lot of squinting. You need to be able to discern 1/32".

Now, here is a recent breakthrough that really adds value to the technique... Resting on top of the toe plate you can see a 24" laser level (about $50 from Sears). This tool shoots a frickin' laser beam out one end. If you are aligning the front wheels, aim the laser toward the rear.

Now, go to the rear and measure where the laser beam is relative to the rear wheel (note the red laser dot on the scale). Do this on both sides. With the steering wheel straight, the two readings should be within about 1/4" of each other. This assures the steering wheel will be straight when you are driving down the road.

If you repeat the process when aligning the rear wheels, the laser tool allows you to set rear Thrust Angle (thrust angle is what assures the rear wheels are pointed straight ahead with respect to the chassis). It is the Thrust Angle aspect that has been missing from my procedure for many years, but thanks to Sears, the puzzle is finally complete.

My wife's car had some issues that caused me to bring it to the local alignment shop. I took the opportunity to do my measurements before and after. It seems to me I can come within about 1/32" on toe and 1/4 degree on camber compared to their $30,000 wonder machine. Probably not good enough if you are preparing for a qualifying run at the Indy 500, but good enough for me and my humble purposes.

One final note... This could save you money, but only in the long run. You'd have to do a bunch of alignments to recoup the money you spent on tools. It will never save you time. Tweaking your suspension setting is tedious if you have to do it on your back on the garage floor. It also requires a lot more effort than sipping bad coffee while watching CNN in the waiting room of the Firestone shop.

The only reason to actually do this is for the enjoyment and challenge and to have the ability to conveniently play around with alternative settings. Those are reasons enough for me!

 

[the bruce]

:thumbsup:

Did you ever try it with a pair of thin ropes?

 

[Dynjo]

id you ever try it with a pair of thin ropes?

You can find a lot of references to the String-Box Method, wherein you construct a string box around the vehicle and measure distances from the wheel lips to the strings. I could never make it work. The strings just seemed so limp and moveable that it was hard to get a repeatable measurement.

And the strings don't tell you anything about caster or camber. Still need a tool for that.

 

[bostonaudi]

One final note... This could save you money, but only in the long run. You'd have to do a bunch of alignments to recoup the money you spent on tools. It will never save you time. Tweaking your suspension setting is tedious if you have to do it on your back on the garage floor. It also requires a lot more effort than sipping bad coffee while watching CNN in the waiting room of the Firestone shop.

The only reason to actually do this is for the enjoyment and challenge and to have the ability to conveniently play around with alternative settings. Those are reasons enough for me!

LOL I have lifetime alignment at Firestone, I can attest to all the bad coffee! This is tedious to DIY, especially setting toe. The Firestone guys don't seem to care how often I bring it in so I let them do their thing and they actually help with suggestions.

 

[utekineir]

+ 1 for bad coffee and CNN, have found the best results come from going at the dearest time, like when they open in the middle of the week.

Very informative thread though.

 

[uscrew96]

I have doing string alignments for years. When your at the track they work great. When your driver like to bounce of curbs at the track.

 

[Dynjo]

True story...

I was in the stands the last time AJ Foyt ran the 500. He white-walled the right side tires at some point and came into to pits. I could see through my binoculars that the RF tie rod (or something) was bent pretty badly. He's pointing at it and waving like a madman. The crew is just kind of looking at it and wringing their hands.

AJ then disconnects the steering wheel, throws it at the nearest crew member and clambers out of the cockpit. He charges over to the pit tool box, throws open the drawers, and eventually comes up with a BF Hammer. He whacks the tie rod a few times, gets on his hands and knees to sight down the RF tire, whacks the car a couple more times, looks again, and jumps back in the car.

A crew member sheepishly hands him the steering wheel, and ol' AJ screams down the pit lane with tires smoking. I'm not sure if he took the time to bucket his belts or not.

DIY alignment -- Hell yea!