IML: FW: Toe in

I probably should have posted this to the whole list, I didn’t realize there was so much interest in the subject. The following is a recent conversation I had with an IML member off list:

Sent: Saturday, June 04, 2005 6:30 AM
To: dickb@xxxxxxxxx
Subject: Toe in

Dick, I'm having a set of radials ( 235/75 15" ) installed on my '56. The tire shop is mounting them Monday. They can also adjust toe in if necessary.

Saw your post regarding this but don't know where to look in the archives for the info. We are about to leave on a 4,000 mile trip with the car (this Thursday) and would like to have the car set up properly. Can you give me some guidance?

From: Dick Benjamin [mailto:dickb@xxxxxxxxx]
Sent: Saturday, June 04, 2005 7:55 AM
Subject: RE: Toe in

They should know what to do with the toe in. Just double check to make sure they are aware that the toe-in has to be set to zero or thereabouts with radials, not to the setting that the book says for that car. If they show a blank face, take the car to an alignment shop that has been in business long enough to remember when the great radial revolution (no pun intended) began in the 80s, when all the older cars were being changed over. Any alignment tech who has been in the business long enough will know about this.

The reason for it, by the way, is that radial tires track much more accurately than bias ply tires. With bias ply tires the alignment spec says to keep the tires somewhat toed in so that the car will not wander. With radials, this is not needed, the car will go where it is pointed without having the sideways pressure caused by the toe-in. If the toe-in is left at the old spec, it won’t do serious damage, but it will reduce the tread life of the radials, and also make the car somewhat “twitchy” on the road.

Good luck with the new tires. You might want to measure the ride height before and after the changeover – folks on the list will be interested in the result. Pick a flat level parking place and measure from the road surface to a point on the rocker panel directly under the “B” post (between the front and rear door) and record the measurement before and after the new tires are mounted. Depending on what was on the car before, it will drop an inch or two – be careful negotiating dips and driveways until you get used to the reduced clearance. I have radials on one of my 56 Patricians, and I have to be really careful on dips and driveways. Fortunately the Packards have an automatic leveling system, so if I pause in a dip, it will level it self out and I can creep through slowly.

Dick