excess wear on outer edge of front tires

[Goldie]

Car was restored about 6 years ago. About 5K miles since. Too much wear on front outer edges. Is this likely too much + camber or could it be toe in. Rears are wearing okay. How can camber be adjusted? Two types of mod's available that I found: 1. remove top shock plate and reweld an adjustment plate, or 2. cut slit in shock tower below top plate, remove welded nuts, and install a slider plate. 1967 BJ8

 

[Keoke]

Car was restored about 6 years ago. About 5K miles since. Too much wear on front tyres at outer edges. Is this likely too much + camber.

Sounds like it to me.

But check the toe in too it could be off causing the tyres to scuff.--Fwiw--Keoke

 

[Legal Bill]

Goldie,

You can get adjustable bushings that replace the rubber bushings in the shocks where they connect to the upright. The adjustable bushings are off-set. You can get about two degrees of negative camber with them. It is about a million times easier and less expensive than the two methods you mentioned.

 

[red57]

I suggest taking it to a tire store/suspension shop and ask them to simply check and document settings & set tow (explain that to them that nothing is adjustable but toe) then you know where you are and what you need to do. In my area it isn't really too expensive and then you really know.

Obviously make sure they can deal with low ground clearance getting on/off the test bed - I've had best luck with places that have a pit and you drive straight & level onto the rig.

If it turns out your camber is off, I agree with Legal Bill, the off-set bushings are definately the way to go unless the frame is way off.


Dave

 

[wheelguy]

Have your toe in set as close to 0 as possible. Plus or minus a 1/16. That is the best setting for toe in.
Wheelguy

 

[Randy Forbes]

If I remember correctly, this took my car from about one degree positive (1*+) to about one and one half degree negative (1-1/2*-).

I still have never gotten an explanation (even from vintage racers running Bugattis) of the logic of running postive camber; anyone here know?

 

[Legal Bill]

Randy, please remind us, did you have those made, or did you buy them?

 

[Bob_Spidell]

...
I still have never gotten an explanation (even from vintage racers running Bugattis) of the logic of running postive camber; anyone here know?

My father--who was an auto shop teacher and factory rep for Ford--explains it thusly:

If you place an ice cream cone on its side and roll it, it will turn towards the small end of the cone. Camber--if you imagine the tilt of the wheel forming a cone with an extended axle line as its center--causes the tires to want to turn as well, to the outside in the case of positive camber. That causes the two front tires to try to turn away from the car as you drive, restrained, of course, by the steering rods. This takes up slop in--and generally tightens--the steering which is compensated for by a bit of toe-in. I suspect--but don't know for sure--that modern rack-and-pinion steering requires less as it inherently has less slop than gear-type steering mechanisms.

Also, camber goes increasingly negative with body roll, which increases the tire patch and grip and helps turn the car. Negative initial camber gives better 'turn in;' good for racing but making steering a bit too squirrely for most everyday drivers. A little positive camber probably gives a little understeer, which is considered a good thing for average (i.e. bad) drivers.

 

[Ed_K]

Hello Goldie,

Welcome to the forum.
Look at all of the advice you got already.
There are some very Healey knowledgeable folks on this forum.

Ed

 

[Randy Forbes]

Bill: I made those; they were early <span style="font-style: italic">getting to know and understand my lathe & milling machine</span> projects.

They are commercially available now though: https://www.bighealey.co.uk/content/offset-trunion-bush-set

These would be a little harder to set, without the hex and being two (2) piece, than mine are (even though I had to mill a 1-1/16" open-end wrench thin enough to fit in the gap).

Bob: thanks, that's the best explanation I've heard yet. The ice-cream cone certainly puts a different spin on it.

 

[Goldie]

Thanks for the advice. I just received two new tires for the front and will have them mounted. Then will have shop check toe-in ASAP. Weather here is not so great right now. I already have the off-set bushings but only installed on left front so far. I will add the second one next. I have been expanding my garage to 3 bays since July and just finished so I have put off car work for about 4 months. If off-sets don't work, I am trying to decide what next. I have heard toe-in should be zero to about neg 1/16" so at least I know where that needs to be. Also heard +1 to zero on the camber is good for these cars.

 

[tahoe healey]

How old are the tires? If you can see the wear after only 5K you may have a serious problem. If the tires are much older the re-builder may have fixed the problem but left the tires. I'd get a tire store to check the alignment out as suggested above.
TH

 

[Legal Bill]

Thanks Randy. That's what i thought.

Goldie, did you put in the bushings before or after you noticed the tire wear? If it were my car, I'd try .5 to 1 degree of negative camber.

 

[Goldie]

added the offset after I noticed the tire wear. Car has been parked in storage while I was redoing my garage so it wasn't being driven. Garage is now done. Now time to fix it. Just got 2 new tires for the front. rears are wearing okay. left front is worst wear than right front. Both wearing to the outside. the outer half shows the wear.