When I purchased Sippy I noticed that the outside treads on the rear tires were worn. The previous owner said that he had the car aligned but it "didn't take". Not a huge issue because 13" non-performance tires are pretty cheap but I figured I would play with the alignment some instead of taking it somewhere and paying money to get a crappy alignment again. After about 6 months of driving on the worn tires I was ready to tackle the job. Actually, I'm only working on it because I'm hoping that it will increase my mileage a little bit (yeah, fat chance on that but I can still hope).
Here's how the tire wear looks on the left rear (driver's side):
The wear is being caused by too much toe-in:
Even though there is no adjustment on the camber for the rear wheels on a Geo Metro I wanted to take a quick look at it. I jacked up the rear of the car a bit and put a sqare on the floor to take a look at how far off the alignment was:
I found that the LR had a gap of 14/16" at the bottom and the RR had a gap of 3/16". This is not adjustable without doing some modifications (maybe later):
I next wrapped a tightened string around all 4 tires and put a pencil between the string and the tires to see how far off the front of the tire was from the rear. What I found was that I had 1/4" of toe-in on both my rear tires:
To change the toe-in you must adjust the eccentric alignment bolts. Here's what they look like:
Here's what it looks like on the car. Noticed that there is an alignment mark on the frame directly below the eccentric bolt. I put a dab of white fingernail polish where the bolt lined up with the mark so I could return to "normal" if I needed to:
The object is to turn the bolt to make the alignment arm move inward. This will "shorten" the arm and pull the rear of the tire in closer to the car (and push the front of the tire outward). You can see how far I had to move the bolt:
Here's a better look at the alignment bolt and how it affects the arm. This is adjusted for maximum toe in as a reference:
I also took the opportunity to check my front wheels as well and set them to 0" toe-in vs the 1/4" and 1/8" that I currently had. Note that my steering wheel is clocked sideways when the tires are straight. It was much further out than that before and I ended up pulling the steering wheel off and making an adjustment there. Of course, it wasn't nearly enough so I'll do it right this time. Just make sure you put it straight ahead before adjusting the front toe-in:
As I started to get all the wheels running straight my pencils were falling off. I held them on with some tape:
Here's what I will be adjusting. There is a 19MM nut on the tie rod end (geez, my bushings have seen better days). Just loosen that nut and turn the inside rod (closest to the center of the car) to move the rear of the front tire in and out. :
So, how did the alignment work? Well, I adjusted the toe-in on both the rear wheels from 1/4" to 0". I also adjusted the toe-in on the front left wheel from 1/4" to 0" (I think the front right wheel may already be close to 0"). With my crude string and pencil measurements I couldn't really tell if I was at 0" or 1/16". I might try fishing line next and really tighten it up for a closer tolerance. In any event, I am much closer to 0" toe-in on all four tires and that should give me better wear on the tires and better mileage. I thought the drivability may have suffered a bit as I got closer to 0" toe-in but WOW was I wrong. The car drives much better now than it ever had before. I was close to buying new shocks because of the horrible suspension that the Metro had. After changing the alignment the car no longer feels like it is going to fly off the road with every little bump that I hit. This is definitely the best modification that I have done to the car so far. Also, I am ecstatic that I finally have a steering wheel that isn't clocked sideways while I drive down the road.