Sometimes they think that you mean you don't want it jacked up while being aligned, and because they didn't listen they think you're an idiot.

It's possible they goofed up. It's also possible you didn't let it settle enough before aligning.

 

Mine did that as well. You definitely have your front tires toed out. It eats the inside shoulders off them in a hurry.

 

Sounds as if the tech heard that he couldn't align the car with it jacked up, but didn't believe that it couldn't be jacked to check the condition of the ball joints, tie rod ends, etc.

Easy enough to check - hold two long straight planks or similar objects against the front tires and see if they are just barely toed in (slightly closer together at the far ends than just in front of the car.

A standard 24" carpender's level will show you the approximate camber - all you need is a level spot.

 

Dean- I have a carpenter's level setup to check camber and an inclinometer.

 

Do a search on "DIY Alignment" to get some info on how a few of us have managed to get all the wheels pointing in the correct direction at the same time. I think Bill Ball started it, and more than a few folks have contributed to it. I made a couple laser fixtures using metal square stock and some angle pieces from the local metal supply place. I think Bill used some smaller tubing from Home Depot. The laser levels came from Harbor Freight at the time but they no longer carry them. It is however easily possible to make them using a pair of laser pointers, but the dial-in procedure for the fixtures themselves gets to be a little time-consuming.

The pre-eminent tome on 928 alignment is on Earl Gillstrom's website, currently unavailable thanks to IB still working on their server and DNS database issues. Dean, PM me with your e-mail addy and I can probably find a way to get you an archived copy from my system here.


BTW, the wear on your tires is from excessive toe-out. This happens not just from an alignment done without having the suspension settled well, but also happens when the springs sag over time. If the car is sagged significantly from the correct height even when it's "settled". As others mention, the ideal neutral point has the lower control arm and the tie rod level when the alignment is done. As the car sags on the springs, both the control arm and the tie rod will remain somewhat parallel at straight-ahead, but they do slope up towards the wheel end. The differences in angle contribute to toe change, and that difference become more pronounced as the car sags more. Point is that the resettling of the suspension become much more critical on a car that's at 150mm height compared to a car that's at 170mm static, the bottom of the acceptable range per the WSM. So getting the car back up closer to spec ride height will help a lot too.

I have a PDF someplace of my instructions for making the laser fixtures. It's obsolete now since the original laser levels are no longer available, though. Do spend some time reading Earl's stuff. Even if you don't do the work yourself, you'll have a much better understanding of what makes it all play well together.

 

I took one a 2x4 and centered it on the OS first slot in tread and centered camera on 2x4 then pivoted the camera end of the 2x4 until I could line up front to rear tire....this is what I have. When you compare where the spoiler/fender hits the tire ( I doubt that is an accurate dimension ) the driver side is toed out farther than the passenger side.

 

It's supposed to be a nice day tomorrow, so I'll try and do my write up for everyone.

As Dr bob pointed out, Capt'n Earl was the originator of the DIY 928 alignment. My work is largely based off of his, but I have developed an excel based calculator that any dummy (No offense) can understand... I hope. Just measure, punch in the numbers, and it will spit out what you should correct it to.

Tomorrow, my goal is to photograph all the steps and put it into a step-by-step writeup. Let's see if I achieve my goal.

 

I think that it would be much more meaningful if you took two 2x4s and put one on the outside of each front wheel, across the center of the wheel, with the bulk of the 2x4 sticking out past the front of the car. You can use bungee cords, ratcheting tie-downs, wife, children, friends, neighbors, etc. to hold the boards against the wheels. Measure just in front of the tire, then as far out as you can. The distance should be almost the same, with the far ends being slightly closer together. Yours will probably have the far ends farther apart, which is toe-out.

 

I will try that as well Wally...and I await your writ up Andrew.

Just for fun I pulled a tape across the front wheels...They are dead on. I measured inside ti inside of the farthest grove...front and back 4" off the floor is 65 15/16". I would of thought I would of seen a difference.

 

Andrew - I don't want to jump on your parade but attached is a simple spreadsheet I made up some time ago to do just what you are suggesting.

Fill in your own data in the blue squares and it will give you the measurements you should be looking for.

Feel free to use any / all of this for an improved version.

 

you cant get enough negative camber to do this kind of damage! its toe out, all you need to do is figure out how much and adjust the nuts on the tie rods yourself. this always happens with alignments that are done by technicians that are not aware of the 928s propensity to ride much higher if the car is raised during the aligment process.

mk

 

the tap measure is a good indication of things being good, unless the car hasnt settled yet. what i do, is put a level against the tire or rim and make marks on the ground. marks front and rear. With the 4 marks, see the distance of the front marks vs the rear marks. (similar to what you did with the tape measure, but you are getting more of the true width of the tire, rather than the bottom arc of the tire). if you are seeing more than 1/8" toe out, you have an issue. generally, you should set it up at 1/8" toe in to be close to in spec and perfect for best wear.

camber is a very easy check with the carpenters level. if you put a level up to te tire and you see more than 15mm (about .5") to make the bubble level, you have about 1.5 degrees camber. that wont be enough to chew up the inside edge. I run race rubber for 1000s of miles and have flat wear patterns with near 2 degree camber in the front and rear.

mk

 

In post # 1 you had the car jacked up. Unless you've driven 100 miles(give or take) in the last 22 hours, it hasn't settled. So your measurement indicating ~0° toe would seem to back up the notion that it was aligned when it wasn't completely settled.

 

Can't open the attachment.

Edit: Got it.

 

That's a good quick check but the measurements shouldn't be dead on. The toe spec is 15' toe-in (+/- 5'), i.e. 1/4 degree. If your measurement-points on either side of the tire are 18" apart then 1/4 deg would be a measurement-difference of just over 1/16". (18" x sin(0.25 deg) = 0.079"). So, in theory, your front measurement should be a fat 1/16" smaller than the back measurement. That's enough to see on a tape measure.

So (assuming the car was settled) you are 10' outside the spec, and in the direction that would scrub the inside of the tires. Enough to do that sort of damage to the tires? I don't know, but it seems unlikely.

Here's your next test: Grab the left-front tire and give it a twist into a toed-out direction, i.e. pulling the front side outwards and pushing the back side inwards. Same for the right-front, again pulling the front side outwards. And with some serious conviction-- you are forcing any slop to be max toe-out on both wheels. Take a measurement across the front side of the tires.

Now shove the tires the opposite direction, front-in and back-out, i.e. max toe-in. Repeat your measurement-- it better be the same. If not, something is loose. You need to shove pretty hard to get the tires to move against the floor. Lock the steering wheel if needed, but don't use a centering-bolt in the rack- that will mask any play in the rack. And if the tires are real sticky on the floor then park them on a couple of plastic trash bags.

Why is the factory toe spec 15' toed-in? That's pretty common and I am guessing that it is to compensate for the wheels tending to toe-out a bit on the road due to rubber bushings, etc. Or maybe it is for quicker turn-in, I don't know. IIRC the early 911/912's were set to zero toe with a preload, a spring-rod shoved between the front of the tires to take up any play.

Happy hunting!