Front toe - check

[englishmaninwales]

New front tyres and toe check tomorrow...(wear pattern on old tyres suggest currently toe out). I see the manual states the front toe in as 4.76 mm to 1.6 mm with the car loaded to 6” front ground clearance. I presume the figure given is divided equally each side? (I’ll set it to the centre of that range which I calculate as 33’).

Car is exclusively used for road driving.
Thanks.
Malcolm

[StressCraxx]

Hello Malcom,

Even though the camber and castor are not adjustable, I would suggest checking them while you check toe. More than just toe can affect tire wear.

Suggest you have the bushings, upper ball joints and trunnions inspected for wear unless they are nearly new. No amount of careful alignment will help if the suspension is worn.

Best regards,
Dan

[englishmaninwales]

Thanks, Dan. Yes I’m planning to get front camber check too, although I’m unsure if they’ll check castor for me. It’s having it’s annual roadworthy test (MOT) at the same time so any wear should come to light, although I checked all the front suspension last week for wear and it appeared ok.

Any feedback on the toe above - is the quoted figure divided equally between each track rod?

Thanks
Malcolm

[StressCraxx]

Castor is easily checked with the camber gauge by the technician. It very seldom requires attention unless the shock tower is bent.

The specs call out total toe-in, so 1/2 the spec per side.

[englishmaninwales]

Thanks Dan.
Malcolm

[baileyman]

Can't washers be slipped into the standard upper arms to somewhat adjust castor?

John

[Foxie]

When I eventually checked my Plus 2, the front camber was way off, positively different on both sides. The rear camber was positivly wrong, and the rear toe was unequally positive on both sides.

Correcting all these settings made a truly remarkable difference to the feel of the car.

[Esprit2]

Can't washers be slipped into the standard upper arms to somewhat adjust castor?
John

NO. The trunnion has two simple bores (suspension up-down, and steering pivot), and zero compliance in the caster direction. The caster is built into the chassis, and any attempt to 'shim' more caster into the suspension will put the trunnion into a bind condition. It will wear more rapidly, and worst case, can fail.

Canly Classics makes a conversion kit that replaces the lower trunnion with a ball joint. Install that kit, then you can go nutz with caster. But short of that, don't mess with the caster.

Regards,
Tim Engel

[661]

Can't washers be slipped into the standard upper arms to somewhat adjust castor?
John

NO. The trunnion has two simple bores (suspension up-down, and steering pivot), and zero compliance in the caster direction. The caster is built into the chassis, and any attempt to 'shim' more caster into the suspension will put the trunnion into a bind condition. It will wear more rapidly, and worst case, can fail.

Canly Classics makes a conversion kit that replaces the lower trunnion with a ball joint. Install that kit, then you can go nutz with caster. But short of that, don't mess with the caster.

Regards,
Tim Engel

A number of racers do shim the upper ball joint to gain more castor, but as pointed out this utilises the poor tolerance fit of the vertical link and the trunnion and will excessively wear them ( mainly the brass trunnion)

[Esprit2]

Rubber bushings allow you to get away with shimming in a little more caster. You're still putting the trunnion into a bind, but the rubber bushings' compliance makes the issue less severe. If you go to harder urethane or Delrin bushings, or even spherical rod ends, the effects of more caster become more extreme, and the eventual trunnion failure will come more quickly.

But no matter how you look at it/ rationalize it, adding more caster has a mechanical wear/ failure consequence.

Regards,
Tim Engel

[englishmaninwales]

New front tyres; toe in was miles out, so set to middle of the specified setting. Camber, after toe correction, was equal both sides and within range. The tester was unable to check the castor angle with his equipment.
Marked improvement to the car! Passed MOT too.
Thanks for the usual good advice.
Malcolm