DIY Wheel Alignment

[Oka]

Hello folks, With three cars to work on. What would be the practical method to do wheel alignments?
- Pay for the service on all cars?
- Use home made contraption (magnet, rope, etc)?
- Buy a cheep alignment tool kit?
Thanks.

[Pennhaven]

Hello folks, With three cars to work on. What would be the practical method to do wheel alignments?
- Pay for the service on all cars?
- Use home made contraption (magnet, rope, etc)?
- Buy a cheep alignment tool kit?
Thanks.

If you have the time and patience it's not rocket science (though it helps to understand trigonometry) to set toe and camber at home. I've done it on several vehicles including the XC70, when I've become frustrated with so-called "techs" not getting it right after repeated attempts. It can take a good bit of time though, and isn't worth it in my opinion, if you have a good alignment tech nearby that you can afford.

As mentioned there are good inexpensive devices to measure the distance between the wheel front and rear edges precisely. The rest is math. The challenge with toe though can be keeping the steering wheel centered, sometimes requires time consuming offsetting adjustments on both sides.

Camber can be checked with a homemade plumb bob and a precise ruler. I've used fishing line and sinker for a precise plumb line. You also need to fashion some kind of bracket to hang the line from. You can do this with a coat hanger and some duct tape, though something a bit more rigid would be best, as you need to keep the line from oscillating back and fourth. Also to get it precisely correct you want the car to be sitting on a level surface, or at least the two opposite wheels at the same elevation and the surface under them angled the same way relative to the center of the vehicle.

Bottom line, if you are a precise, patient person with more time on your hands than money, go for it.

[howardc64]

Toe is super easy but hard to get super precise at home, here is what I do

- layout 2 straightest 2x4s in front and rear of the car on jacks, tie a string on both car side
- check distance between strings on 2x4 are identical for front and back 2x4
- center of wheel to string same on both left and right wheels
- once have this perfect rectangle around the car, then adjust tie rods and toe angle by checking distance between string and leading/trailing edge of the wheel. 2 people helps (1 to adjust, 1 doing the reading) I used a micrometer and maybe have the front wheel's leading edge point 1mm inwards more than the rear.

I think this jig cost me like $5 at homedepot for 2x4s in the damaged wood pile.

On camber, don't worry about camber. Not enough angle adjust on this car to matter (just the play on those 2 bolts that secures the struts. I doubt most alignment shops even mess with it. I have never seen camber tire wear no matter how many times I've cracked those 2 bolts loose.

[Pennhaven]

Toe is super easy but hard to get super precise at home, here is what I do

- layout 2 straightest 2x4s in front and rear of the car on jacks, tie a string on both car side
- check distance between strings on 2x4 are identical for front and back 2x4
- center of wheel to string same on both left and right wheels
- once have this perfect rectangle around the car, then adjust tie rods and toe angle by checking distance between string and leading/trailing edge of the wheel. 2 people helps (1 to adjust, 1 doing the reading) I used a micrometer and maybe have the front wheel's leading edge point 1mm inwards more than the rear.

I think this jig cost me like $5 at homedepot for 2x4s in the damaged wood pile.

On camber, don't worry about camber. Not enough angle adjust on this car to matter (just the play on those 2 bolts that secures the struts. I doubt most alignment shops even mess with it. I have never seen camber tire wear no matter how many times I've cracked those 2 bolts loose.

My experience with camber, on this and other rack and pinion cars, is that if it is too positive there is diminished steering feel and return, which is one of the reasons I messed with it myself after a "pro" aligned toward the positive side of the spec. One of our members (Bill99?) has mentioned here that he always adjusts the struts to achieve the maximum available negative camber, and I think that's probably good advice for most of these cars, assuming nothing has been bent from a prior collision. Negative camber is generally favored for handling and racing, and while too negative outside of spec might increase tread edge wear that's not likely on this car as there is only so much negative "slop" in the strut mount holes.

[howardc64]

My experience with camber, on this and other rack and pinion cars, is that if it is too positive there is diminished steering feel and return, which is one of the reasons I messed with it myself after a "pro" aligned toward the positive side of the spec. One of our members (Bill99?) has mentioned here that he always adjusts the struts to achieve the maximum available negative camber, and I think that's probably good advice for most of these cars, assuming nothing has been bent from a prior collision. Negative camber is generally favored for handling and racing, and while too negative outside of spec might increase tread edge wear that's not likely on this car as there is only so much negative "slop" in the strut mount holes.

Make sense negative is generally better with a tiny bit wider stance. I've had one experience where newly installed tires caused a heavy pull to one side (I recall quite common with new tires on P2s when I did the research, no one ever figured out why) I did positive on 1 wheel and negative on the other side to counter this pull with success. Eventually relaxed this camber setting as the pull went away. Didn't notice much difference with my slow driving habits and tall slushy suspension.

Ditto on tread edge wear on too aggressive camber. My daily driver now is Tesla Model S and they designed it with -2+ degrees of camber at the rear. I think this is common practice for Porsches from racing heritage. Reduces tire life by like 50% and worse on bigger diameter wheel options. I think on P2s, the maximum camber is probably < 1 degrees either way so probably a non issue tread wear wise. Maybe someone has an exact limit.

[billr99]

Maybe someone has an exact limit.

If what you are asking is what the range is if you do not use camber bolts in the front, I would say with what I have seen in my 3 P2s that generally its about .5 to .75 degrees plus or negative using just the slop of the OEM bolts in OEM struts. Use a camber bolt in both holes you can see nearly 3 degrees, one bolt closer to 2 degrees. Keep in mind that these measurements are dependent upon the conditions of your springs to at least some measure. Short or fatigued springs will tend toward more negative while fresh OEM springs more positive.

Since there is not an "easy" camber adjustment at the rear I have never messed with it even when I ran Eibachs on my first XC. Even with the nearly 40mm drop those gave I found that the rear camber was in spec albeit toward the negative end of the range. Otherwise be it either the R or XC (sort of the range of stock P2 suspensions short to tall), I have never had camber out of spec. Either the bushes back there are fairly stout or even with some wear on bad roads the design keeps things in check unless you go to a more radical spring. Now with a load where you get the rear to squat pretty good, I would say just by looking at it that you could see a good 3 degrees which is where you will start seeing tire wear. As some have reported when using a fairly short spring in the rear.

Finally and just repeating my two cents on camber, with the way I have adjusted most of my cars over the years, not all Volvos, I have found that going 1 or 1.5 degrees negative had no effect on tire wear. In some cases, again not Volvo, it would produce a bit of bump steer if it was toward the most extreme part of the camber range; but overall, the increased grip was well worth the effort, especially on cars that tended toward oversteer in stock form.

Anyway, my two cents

Bill

[Oka]

Thanks.
Mmm, your "two cents" is priceless.

Just curious, what is ". . . bump steer . . "

[howardc64]

If what you are asking is what the range is if you do not use camber bolts in the front, I would say with what I have seen in my 3 P2s that generally its about .5 to .75 degrees plus or negative using just the slop of the OEM bolts in OEM struts. Use a camber bolt in both holes you can see nearly 3 degrees, one bolt closer to 2 degrees. Keep in mind that these measurements are dependent upon the conditions of your springs to at least some measure. Short or fatigued springs will tend toward more negative while fresh OEM springs more positive.

Since there is not an "easy" camber adjustment at the rear I have never messed with it even when I ran Eibachs on my first XC. Even with the nearly 40mm drop those gave I found that the rear camber was in spec albeit toward the negative end of the range. Otherwise be it either the R or XC (sort of the range of stock P2 suspensions short to tall), I have never had camber out of spec. Either the bushes back there are fairly stout or even with some wear on bad roads the design keeps things in check unless you go to a more radical spring. Now with a load where you get the rear to squat pretty good, I would say just by looking at it that you could see a good 3 degrees which is where you will start seeing tire wear. As some have reported when using a fairly short spring in the rear.

Finally and just repeating my two cents on camber, with the way I have adjusted most of my cars over the years, not all Volvos, I have found that going 1 or 1.5 degrees negative had no effect on tire wear. In some cases, again not Volvo, it would produce a bit of bump steer if it was toward the most extreme part of the camber range; but overall, the increased grip was well worth the effort, especially on cars that tended toward oversteer in stock form.

Anyway, my two cents

Bill

Really great summary. On the Tesla Model S, I think I can actually see the aggressive camber angle of negative ~2.5 degrees (or maybe its my imagination since I know the problem is there haha). 21" wheels has much greater inner lip wear over the 19" and air suspension that lowers the car on highway makes it even worse. All of this echos your explanation on load, lowering springs etc.

[AutosDirectFlorida]

The 2x4's and string is similar to what I've done in the past.
I used 4 jack stands with a metal rod and strings running front to back.

First issue is track width as most cares are not the same front and rear - no idea about the XC.
But getting the string around the car squared properly is more difficult when the track is different front to rear.

Biggest issue with a single device toe adjustment like the bar is thrust angle.
You need your measuring tool/device to be square front to rear to keep the thrust angle correct so you dont look like you're driving sideways down the road.

[billr99]

TFirst issue is track width as most cares are not the same front and rear - no idea about the XC.

Track width is indeed narrower in the rear of an XC by 60mm, 30mm for an R or V70AWD.

What I do when I "string" a car is remove the hub cap and measure from the head of the axle bolt. The assumption here is that when torqued properly the surface of the head of the axle bolt is equal distant within a few thousands from the car's centerline as the one on the opposite side and that the subframe on that end of the car hasn't been whacked out of position. So I then adjust the string so that the distance from the string to the bolt head is 30mm less (half of 60, right) than the similar measurement at the front. You need to consider this as otherwise you get a toe-out at the front and the thrust angle is screwed up. You then take your toe measurements from the front and rear of the wheels on a plane level with the center hub. When you "string" a car you may not be as accurate as a laser alignment setup, but if you take care especially with your measurements from the references points, like the bolt heads I referred to, and the string you can get well within the spec tolerance. I would also argue that seeing how some of the techs running the laser machines these days do it, I would bet my geezer eyeballs and my string against them any day. When I raced, this is how we setup the cars (Spec Racer Ford, Formula Ford and Showroom Stock cars) and it worked great.

As an example of the level of accuracy you get with a "professional" alignment these days. I just bought a 7 Series BMW that had just had an alignment after a toe link change. The paperwork included the alignment results and the tech had setup the front toe, albeit in spec, unevenly side-to-side and toward the extreme toe-out side of the spec. With the 20in rubber on the car, the car was a bit squirrelly. I "strung" the car, dialed the front toe back about half a turn on the tie rod that was the furthest from ideal and the handling came right back (I did this to make certain I didn't have some kind of un-associated suspension problem). I then went ahead and basically re-did the front alignment bringing the toe-out, in this case, more equal side-to-side and closer to the more zero toe side of the spec. Now the car handles rock solid. It is important to remember when you do all of this that things like wide tires, especially those with extreme low profile (this car has 40s in the front 35s in the rear) can really react to slight changes in toe so it doesn't take much to throw the handling off or bring it back. But in any event, there is no reason that anyone with 4 jackstands, a ball of string, a metric rule, a bit of level pavement and an hour of time can't do an alignment, at least for toe. Camber is a bit more of a pain and it is helpful to have something like this (http://www.longacreracing.com/produc...%84%a2-Adapter) to do the readings. I actually made my own using some 3/4" angle aluminum and a digital level and it works well enough to get within a couple tenths of a degree. And for me the real advantage is that I can correct an alignment issue (thanks for our crap roads here) straight away and not suffer any undo tire wear as a result.

Anyway, my two cents

Cheers,

Bill