Tracking/Wheel Alignment 2B Plus

[Bob Tucker]

You can check the camber easily enough, if a bit inaccurate.

 Get 2 13mm  (ish) nuts, tiewrap them to a long spirit level. Park the car on flat level ground, slide the nuts up and down so they touch the top and bottom of the rim. The bubble will tell you if the wheel is canted in or out at the top. Ive adjusted mine to about 1/4 bubble in at the top. & it does pretty well on trackdays and no adverse tyre wear.

[Leslie Walters]

Don't really understand why the readings are so different on the toe's, however I would suggest a setting of parallel to a small amount of toe in (toe in will help with steering stability) and front camber of 1 to 1.5 degrees negative, excessive toe out would cause inside edge tyre wear.

You also have to consider that adjusting cambers will affect the ride height and vice versa and will also affect toe's so they must all be checked in conjunction.

[alanrichey]

52 minutes ago, Leslie Walters said:

You also have to consider that adjusting cambers will affect the ride height.

I wasn't aware of that, but researching on the net gives lots of different answers.  Some say 'yes' and some so 'no' but the majority view seemed to be 'yes but negligible'.  I think the best answer was this one: 

"Camber change will have no significant effect on ride height...but if you change ride height that will change camber, toe, and caster ..."

So winding up my springs to increase ride height will have affected everything   I'm happy the tracking alignment is still within limits (According to the manual the reason for the two different reasons is caused by slightly bent wheels).  But I am still stuck with tight locknuts and until I find out the thread directions I can't change the tracking.

I see that castor measuring devices are only a tenner on the Bay, so I think I will treat myself to one.  Although I will leave any adjustment to an expert as it will involve breaking the top ball joint and I don't fancy doing that.

[Leslie Walters]

Pretty much all the track rods I have come across are right hand thread (conventional) if there is any thread visible a visual check would confirm the thread direction.

[alanrichey]

Never thought of that   Mine is all covered in masking tape so it's not obvious.  Thanks

Al

[Peter Bell]

It's not always necessary to split the ball joint Al, can you just pull out the dummy strut from the upright, or have you got those very long ones?

[alanrichey]

No, I don't think so.  Interesting option.

 

[alanrichey]

So checked the camber with a cheap and cheerful gadget off EBay.   It was surprisingly good.   I checked 3 or 4 times, moving the car each time and the readings were pretty consistent.

However, not sure they make sense, remembering that the symptoms were excessive wear on the nearside front tyre and a tendency to pull to the left.

The nearside front wheel showed 1º negative, which is apparently quite acceptable.  The offside front wheel showed 1.5º positive, which is not advisable, although there is minimal tyre wear on that side.

So not much further forward, although I might get the offside wheel adjusted.

[Peter Bell]

I doubt if you will get it any closer than half a degree, as you have to turn the ball joint a whole turn, are they 1.5 pitch? If it pulls to the left on braking check the rh caliper is working properly and not slightly rusted/sticking 

[alanrichey]

I think a complete rotation of the top ball joint is 1/4 degree, so you can make fairly fine adjustments.  Brakes are fine, just passed MOT.  And the pull is there all the time, not just under braking.

[Grim]

Small changes to camber don't cause significant tyre wear. Unless there's excessive play in your bushes or other mechanical damage etc, the toe out is the only possible cause. I'm slightly concerned you get such large deviations in your measurement of toe - this suggests something is bent. Could it be run-out of the wheel? Can you swap it to another to get more repeatable readings? I have a track-ace and I have not found any noticeable deviation in measurements depending on wheel position.

[alanrichey]

Right, spent a couple of hours taking multiple readings of both tracking and castor.  My garage was long enough so I could actually roll the wheels through 360º and then back again.  So I took readings every 90º forwards and then repeating backwards, giving me 8 readings.  The castor was consistent on all the readings varying only by 0.1º, with the nearside (the one with the tyre wear) showing 0º and the offside showing +2.5º.

As before, the tracking was a bit variable. although I did the recommended procedure of aligning it on the nearside wheel then checking the tracking on the offside wheel then back to the nearside to make sure it was still zeroed.   Using the valve as my guide, I got the following readings

6  o'clock    10' Toe-out  &  8' Toe-out
9  o'clock      8' Toe-in    &   5' Toe-in
12 o'clock     5'  Toe-out &  2' Tow-out
3 o'clock       3'  Toe-out &  1' Toe-out

I'll repeat the exercise in a few days, but I think we can safely say that one or both of my front wheels are slightly distorted but that overall I am probably looking at a small amount of toe-out.   I think for next time I will swap the front and back wheels and see what effect that has.   Meanwhile, those values are so small that it's not worth losing and sleep over it and I will just carry on driving   (Although I might look at getting the camber on the offside reduced).

Al

[Peter Bell]

Hi again Alan, I'm surprised at your castor angles presumably you have very little steering self centering, can I suggest you try to increase the nearside to at least equal the offside. 3° to 5° I think is the accepted norm, perhaps this would help the left side pull as well.

[alanrichey]

Hi Peter

Sorry, mistyping, I meant camber not castor.  In fact my self centring borders on brutal.  If I am in a turn and relax my grip on the wheel she will snap back to straight ahead instantly.  One of the reasons I am loath to change anything