Alignment Toe In Question

Any alignment mechanics and experts out there??

So, I"m pretty well building from scratch a single axle w/electric brakes, combination car tow dolly (front car wheels up on dolly, rears on ground) and golf cart hauler (sideways on trailer up in front of car) so when I take my Golf Cart and car to Florida next year I don"t have to double tow again (towed car 4 down with golf cart trailer behind car last 2 years, too freakin longgggggggg although never any problems).

Question is I understand due to the crown of roads I need the trailer wheels towed in just a tad so the tires wear even BUT HOW MUCH TOE IN IS MY QUESTION, heres the specs.

Tires are nearly 8 ft apart side to side
Tires, 205 75 R 14 6 Ply Load Range C Trailer
Duty
Tires are approximately 26 inch diameter

I went out tonight and based on my mechanic buddys advice (does alignment work) when each tire is measured from it widest to widest points (about 20 inch diameter) the front tire wide spot is towed in 1/8 inch closer to frame then rear wide spot (20 inches back). Of course, if you measure all the way across then its 1/4 inch closer (toe in) in front then in rear from front high spot to rear high spot 20 inches back.

Is that enough??? Too much???

I plan next week to haul it over to his shop as he has one of those skid toe in measure bars across the floor which registers when you drive over it but just curious in the meantime..

Ol John T and all in Indiana

This came up on trailer axles once so I called Dexter axles and asked. For spring axles the goal is o deg. toe with all tolerance to toe in, or 0-2 deg toe in. For Torflex axles they go with 5 deg. of toe in.

On my goose neck which is a tri axle, I went with 1/16th to 1/8th toe in and a little arch in the center of each axle. This is measured with a scribe mark in the center of each tire, all the way around, measured at the center height wise on the tire, and that measurement is the difference from front to back.

John T
1/4" in is to much. I would go for 1/16" - 1/8"

toe in has nothing to due with the crown of the roads. that is the castor setting. nor do you need toe in on a straight trailer axle.
toe in is set on vehicles so when you are running down the hyway the tires come to 0 degrees. for example if you have worn out tie rods then you can be running with toe out due to the extra clearances in the wear. with the old bias ply tires more toe in was required, and with radials it is set closer to zero, like 1/16".
on a straight axle trailer you only adjust the camber.

John I wouldn't worry about toe in as much as the camber. Toe in or Toe out can make it wonder all over the road. If you look under almost all trailers you will see how the axles are bent up slightly in the very middle. This is called camber. The axle then can be rotated forward a bit to give enough caster then also. You want the wheels to follow the axle not axle follow the wheels. Which is the caster setting. You may want to ask at a trailer repair shop.

I have a friend who welded new trailers for a living,he says to stagger the axle 1/4 inch. Myself I would set the toe in 1/8 total for radial tires,1/4 for bias tires. That will put you right of specs for a rear wheel drive car or truck. ASE retired.

And you could use a 2x4 with a nail driven at an angle in the end of it with the nail protruding out about 2 inches. Then jack up the tire and spin it and slide the 2x4 upto the tire and scribe a line in the center of the tire. Do both tires and this will give you 2 lines to measure from.

Back when I performed PDI on new tractors I set the toe-in on frt axles at 1/8 inch.

I've been reading/studying suspension design back to when autos were invented. I've never heard anything about toe-in or toe-out setting having anything to do with road-crowns as you mention.
I don't see how it could since crowns vary widely and often do not exist at all.

The idea of a toe-in setting on a stationary vehicle is so when moving - it is zero - i.e. both wheels perfectly parallel to each other. Much as to do with counter-acting camber-thrust from the steering which you do not have.

1/16" is common on trailers. Just enough let the wheels pull themselves into parallel positions when rolling.

Toe-in and Ackerman Angle setting are both there to keep the front wheels parallel to each other when moving. Toe-in when going straight - and Ackerman when steering into a turn (does not apply to a trailer).

Off the subject John,but going a little light on the tires-axle aren't you.You are at your max cap.rating or more.

I have built many trailers, Steel hauling 125000 pound, and utility, none had toein. Camber was used on single wheel axles (maybe 2 degrees positive camber when empty). Rear axles on all solid axle cars and trucks do not have toein, they are fine that way. Jim

The purpose of any toe-in on a trailer is to account for bearing slop so when running - the wheels pull themselves into being perfectly parallel.