I am having my 90 GT aligned on Friday. I already confirmed they don't have to lift it on the machine they will be using. I presume they will have specs., but to be on the safe side can anyone point me to where I would find specs. that would be useful to an alignment shop?

The reason for the alignment is that I wore my rear tires out and I noticed the belt coming through on the inside of the left rear. I am presuming I might have extra negative camber there that I don't want, but since the tires were not new when I put them on the car, there is always a chance that the abnormal wear pre-existed but since there was plenty of tread at the time, I am presuming the wear is from my alignment settings currently.

My GT is strictly street, so I am presuming I want stock alignment settings.

 

The specs are in the WSM, volume 4, section 44, page 5.

 

Thank you Bill, exactly what I wanted.

 

Stan-

On my GT, I'm running -1º 4' of camber IIRC and that was as low as they could get it - most likely becasue of worn bushings in the rear suspension. However, surprisingly the tires are wearing quite evenly. So unless you are running TONS of negative camber on that one wheel, my suspicion is that it's excessive toe that's causing it.

Good luck.

 

Stan,

The GTS is doing the same thing. Other than "naturally" burning rubber off the rear tires, I'm getting WAY more wear on the inside of them. Almost down to the belts on the inside. The outside are still not quite down to the wear indicators. I've put almost 2,000 miles on the car and when I got it, the tires were nearly brand new looking. Toe seems to be the culprit??!!

 

its toe not camber. Im running 2 degrees on soft tires and rarely get any inside edge wear. pretty even, even with the track use.(mostly )

mk

 

Could very well be toe and just on the one side. I will find out tomorrow (I hope)

 

Here is a video that shows you how to DIY a front end toe alignment on a Porsche 928.

You can download the spreadsheet here.
Enjoy.

 

This is great Andrew - and very timely. I'd definitely like to see your camber and caster videos once you have that done as well. The 928 is looking sharp too - love the black wheels...

 

Thats great Andrew...how can I save this to my hard drive? I'm REALLY glad some are starting to do videos. Thanks

 

that was great AO, thanks mmmmkay

 

Nice video, Andrew! One thing that may be worth mentioning, this method may be sensitive to camber differences, more so if the laser is mounted further from the ground when making the first mark. This method seems ideal if the camber is already known, or if it is unchanged(rack/tie rod swap).

If the laser aperture is at the wheel centerline, then every 1° change in camber will move the mark on the floor ~5mm. With your setup having the laser aperture so close to the floor the error will be less, but still potentially present.

 

You can download it here... http://members.rennlist.org/andrewmo...0alignment.wmv


That's a good point. I remember an alignment tech once tell me that toe should be the LAST thing you adjust. First should be caster, then camber, then toe.

I was originally going to show how to do caster and camber, but as you saw... I had some technical difficulties. Earl talks about using drill bits. I'm going to revisit that method to see if I canget that to work for me.

 

Andrew, THANKS for doing the video and spreadsheet, that is really great.

Correct, if you are going to do the whole thing then check caster first- because that messes up both camber and toe. Then camber, which messes up toe big-time.

Caster is a pain and unless there is some reason to suspect a problem (i.e. car tends to pull to one side or the other) then I would vote to forget it.

Camber is pretty easy, our laser also has spirit-levels so I just turn the laser-gizmo vertically and see how much of a spacer is needed at the top to make it vertical. With a 17" wheel something like 0.25" at the top is around 40' of negative camber (arc-tangent of gap-at-the-top divided by the length of the laser-gizmo).

Your plumb-bob method should work well also, looks slick!!

 

Andrew just plain awesome thank you so much. I'm just finishing my front shocks and springs so I need to get it fairly close to make it to the alignment shop. This video will be perfect thanks again for the extra effort.