Front end alignment?

[Timothy Keith-Lucas]

I just noticed that my left front tire is badly worn, unlike the others, despite my not experiencing any pull to either side.  Are there instructions somewhere for aligning the front end? I don't imagine that the commercial shops, with their computerized and laser loaded by the make and model alignments are going to be much help.

 

 

[SENC]

I'll take a look through my files later today to see if I have an instruction document, but it is pretty simple on early Sevens.  Look for the string method for front end alignment as a simple way to measure alignment.  Adjustment is by rotating track rods.  My recollection is that toe-in should be 1/8" (in total, so half each side), but I'll see what I have to confirm that if you can't find it in the shop manual.

[MV8]

 Since it is limited to one tire, it sounds like camber (tapered wear across the tread to where inboard or outboard has tread, but the other side has less) or blown damper (cupping wear around the circumference). A $12 digital protractor can be used to check the camber on each side relative to a centered horizontal surface (windscreen top/cowl/chassis cross rail) since it won't be on a rack. After camber is set, the toe would be adjusted.

[wdb]

Camber frequently gets blamed for uneven inboard/outboard tread wear but it is also possible that toe is the culprit. Look for feathering at the tread edges.

 

I just did a string alignment on my 7. It's a bit fiddly but one can actually get pretty close. Not laser close, but decent.

 

FCP Euro has a pretty nice video on a low-budget string alignment process. This is what I followed on the 7 and other cars.

 

 

My starting point for the 7 was a bit odd so I did a couple of things before starting the string process. The first thing I did was to even out the adjustments on the the tie rod ends, because in my case the number of threads showing on one side vs. the other was noticeably different. I also had an offset steering wheel, so after evening up the threads on the tie rods I took the car for a short spin and see where the wheel rested naturally when going straight ahead. I then removed the steering wheel and re-aligned as closely as possible to center as the splines would let me. THEN, finally, I locked the wheel in the straight ahead position and proceeded with the string alignment. I didn't have any official numbers but a wee bit of toe-in is the norm, so that's what it got.

 

[MV8]

He has wear to one tire. Toe would result in feathering to both front tires.

[wdb]

2 hours ago, MV8 said:

He has wear to one tire. Toe would result in feathering to both front tires.

Great point. 

[IamScotticus]

Those shops with alignment machines don't need your vehicles data, it's only needed for the reccomend alignment for that car.  They certainly can get you to 0 and adjust as requested, with the obvious limitations built into the suspension.  They could show you where you are at now, which could be interesting.   You could have well adjusted angles but still eating rubber.  Something broken, perhaps?

How old are those dampers?

Forgot to add, those ubiquitous reflector alignment machines,  you could get measured from ten different machines and you will get ten different results.   A DIY of string and rule seems much more sensible.

Edited Friday at 02:12 PM by IamScotticus

[fastg]

Talk to your local race and autox fans, I am sure there is a local alignment shop that will be friendly. Most box type shops will only do what's in there database. In Chicago we found Abe and Docs in Batavia. They thought it was cool and set the car up as I wanted. 

 

Graham

 

 

 

[Timothy Keith-Lucas]

Thank you. I did a string alignment yesterday.  The problem was obvious - somehow when I replaced the steering shaft I loosened the locking nut on the left steering arm, and it unwound itself. At present, the left side is straight, with no toe in. On the right side, when the front wheels are straight, the rear wheel toes in by about 1/8 inch from rear tire rear bulge to rear tire front bulge. Is there a way to correct that?

 

The question about bushings is interesting. The ones in the front end appear to be original (1962), but there is no wobble in the steering or in the front wheels when they are on stands. The bushings in the steering universal joint were worn out. I replaced them when I installed a telescoping steering shaft.  That got rid of all the steering play.

[Timothy Keith-Lucas]

It turns out that i did have wear on both front tires, just not as badly on the right as the left. I'm hoping that the loose steering rod locking nut, and subsequent extreme toe in, is all of the problem.

[SENC]

[SENC]

Are you saying there is rear toe-in only one 1 side?  Assuming you have the Standard 10 live axle that would suggest to me an issue with axle location, perhaps from a bent or incorrectly installed radius arm?  But I would expect toe-out on the opposite side in this case - and a tracking issue.

 

If you're saying you have toe-in on both sides, then probably as designed.  I don't remember checking mine.  The live axle doesn't have provision for toe adjustment.  But if you look at other Lotus of the period (like the Europa) that have independent rear suspension with ability to adjust, the manual specs are for a small toe-in (1/8" on the S2 Europa).

[wdb]

6 hours ago, Timothy Keith-Lucas said:

Thank you. I did a string alignment yesterday.  The problem was obvious - somehow when I replaced the steering shaft I loosened the locking nut on the left steering arm, and it unwound itself. At present, the left side is straight, with no toe in. On the right side, when the front wheels are straight, the rear wheel toes in by about 1/8 inch from rear tire rear bulge to rear tire front bulge. Is there a way to correct that?

 

First of all don't measure at the tire, measure at the wheel -- outermost edge, as close to center top-to-bottom as possible. Secondly make sure your wheels are not bent! Raise the car and give them a spin. 1/8" runout is possible.

[straightcut]

This tool might be just what you're looking for to simplify wheel alignments:

 

 

https://gyraline.com/

 

[SENC]

1 hour ago, straightcut said:

This tool might be just what you're looking for to simplify wheel alignments:

 

 

https://gyraline.com/

 

Now that is a cool product!  Have you (or anyone else here) tried it?  I may download the app just to check it out.

[straightcut]

I just saw the video above this morning.  It’s only $80 if you go the pay as you go route plus $.99/use.

[SENC]

19 minutes ago, straightcut said:

I just saw the video above this morning.  It’s only $80 if you go the pay as you go route plus $.99/use.

I'm an Android user (Samsung Flip), and downloaded their beta app for Android.  It's not as "fancy" as the iPhone screenshots in the video, though that may also be part of buying the package.

 

I did the initial sensor test and the app reported more variance than ideal.  I then did the parallel surface test (start on a flat vertical service to get initial "lock", rotate it 10 degrees or more while keeping it on the same flat plane, return to the same vertical surface) and could see the variance visually.

 

I think I have an app on my phone that recalibrates the gyro sensors and will play with that some tomorrow and try again, but it may be that my phone sensors have different tolerances than the iPhones for which the product appears designed.

 

Notwithstanding the above, it's pretty easy to see how you can prove to yourself it would (or wouldn't) be accurate enough for you by mimicking the movements and choosing 2 known parallel surfaces for the 4 wheel readings.  I'd be interested in findings of others, if you try it out.

 

Very cool and simple.  Hope I can get it to work on my phone or that future software enhancements allow calibration to more phone/sensors types.

[MV8]

Unless there is tire damage or rolled cold to where the bottom is now under the string, tire bulge is fine for string alignments. The string is set as high as possible/close to the wheel CL.

 

Nice, simplifying tool AP. Great for enthusiasts who don't want to do the math with $20 worth of tools but can't get an alignment shop to use the customers specs and possibly cheaper as well. Should be close enough with a good phone and cal.

[SENC]

I missed the measurement "by front tire bulge to rear tire bulge".

 

I'm not sure how you'd determine toe in or out without 2 measurements per wheel (preferably at the wheel), and tire bulge suggests to be 1 measurement at each.

 

Comparing front to rear rather than side to side is also confusing.  Perhaps TLK can clarify and we can help better.

[7Westfield]

a homemade set of these is what I use for toe adjustments

https://www.pegasusautoracing.com/productdetails.asp?RecID=12736

 

and a digital level for camber