adjusting toe in.

[bevans6]

A little investigation of toe in on my MCI MC-5C to see about improving the tracking and reducing wander has lead to finding that we seem to have about 1/4" of toe out measured at the tread of the tires.  that's a little more than the 1/16" (who are they kidding, measuring 1/16" across 86 odd inches...) of toe in that is the spec.  So in anticipation of adjusting the toe linkage I have soaked it in whatever miracle lube I had available and I will let it marinate overnight...

the tie link is actually new in 2002, as was the drag link, and is the latest spec.   So here's the question - do I just back off the locking straps, hit it a few times to get it's attention and use my biggest pipe wrench to turn the tie link, or is there a more subtle approach to take?  what is the recommend approach to actually make the tie link turn to do the adjustment?

It's kind of funny, I do alignments on race cars all the time, sometimes to .010" limits, and this bus is asking for .0625" of total toe in at the tread of the tire.  No race car I have ever worked on has asked for that low a limit or that accurate a measurement.  .0625 inches total at what - 3 feet for the diameter of the tire - is less than .010" per side at 13" wheel diameter!  I'm going to be putting way more specific settings on the bus than I do a formula race car!

Brian

Brian

[NJT 5573]

You don't need the hammer!

Just remeasure several times as you go to get some repeatability. I use a pipe wrench, sometimes it leaves a few teeth marks, but the idea is to get the adjustment right.

Try to make sure your last wheel direction was foreward and straight ahead if you can. It don't make much difference what the toe is going backward!

[Stormcloud]

FWIW, an old (eighty-ish) Greyhound bus driver, who is a busnut with his very own MC-7 told me that when I have an alignment done on MY MC-7 to have them set the toe-in at zero, because I have radial tires.

I dont know enough about this to have an opinion, but he is knowledgable, sincere, and has a bunch more miles under his belt than I, he says his coach steers extremely well, and the tires look just fine.

Someone smarter than me may know if this would also apply to your 5C.

Also, my -7  wandered a lot (I thought) until I put 110psi in the steer tires...rides harder but MUCH less wander.

[gus]

I think you're right.

As I remember when checking some of my older vehicles radials are always set with less toe in than bias tires.

Don't remember the reason, but they all said the same thing.

[RichardEntrekin]

Brian,

In my experience if you set the toe in anywhere close to zero it will wander all over the road. The truck shops like to set them up at zero to maximize the tire mileage. I don't know many people who ever wear out tires on their personal rig, so sacrificing a wee bit of tire life for tremendously better handling is an easy decision.

I use 2/32 toe in. I jack the axle, spray paint a stripe on the tire, rotate the tire against a sharp scribe to make a fine line, lower the coach and drive forward about ten feet,  and use a home made trammel bar instead of a tape measure.  For rotation plates I use two pieces of plywood with a folded up garbage bag between them.

Prevost specs call for 1/8 toe in on straight axles

The trammel bar is round aluminum pipe obtained at Home Depot. I have two short pieces of PVC that just slide over the aluminum. I put thumbscrews in the PVC so I could tighten it on the aluminum pipe. I put a sharped nail in each piece of PVC. Works like a charm

[bevans6]

Richard, i like your thinking!  good tips, and i agree with the little biit of toe in.

Brian

[JohnEd]

The "be all, end all" alignment shop in San Diego was Bee Line....right under I5.  I know they had spiffy alignment systems cause I saw two of them at the end of the shop and they had tarps and tools and stuff hanging on them and they were real dusty.  Bee Line did all the Porsche's and BMW's and Jags and Ferrari type stuff.  They used that trammel bar and the white paint and the scribe.  Their rotation plates used ball bearings I have no doubt.  Their techs were old school savvy and honest.  They never missed!  Never. 

I just had my front and rear done on my Ranger.  I have print outs running out my kazoo.  It isn't right but is at the very limits of adjustments....wrecked.  The guy that did the work also owns the shop and is as serious as a heart attack about his work.  I love this guy.....I miss Bee Line.  I hope they are still in business but that was 1990 I last saw them.

Bee Line had a tech that had swastika tats on his neck.  That guy balanced tires on your car, speed balanced, and he didn't use the strobe light.  Just felt the fender with his fingers.  I watched him balance a new BF Euro on my rack and pinion Z car and he did it in 3 spins.....the other 3 took 6 spins.  The guy was spooky good and very pleasant to deal with.  I was invited to feel the fender after he finished each wheel and there was only the rush of air to be felt.

POINT BEING:  you don't actually need all that computer stuff.  It keeps them honest though.

The plywood and bags idea is inspired....thank you.

John