Wheel/Axle alignment

[pcskier]

I was poking around under my new to me 2014 FC 23d today and noticed the tires aren't wearing evenly...less tread either on outside or inside of tire, on a couple of them. Please see the attached crude diagram. I used a 6-foot aluminum level across the tires on each side. I would think the proper axle alignment would mean that each tire would contact the straight edge, for a total of four points of contact on each side. However, on the street side, only the front of the front tire and the rear of the rear tire contact the straight edge, there is a gap on the other end of each of those tires.

On the curb side, the front tire contacts the straight edge on both sides, and the rear tire sits inbound and doesn't contact the tire at all.

How bad of a problem do I have?

[AlinCal]

I would measure from the ball center back to the same point on each side of the front axle and see what it is, may be hard to find that exact spot on each side and may be more accurate to remove the wheels and measure ball to center of wheel hub on each side.

[pcskier]

Originally Posted by AlinCal

I would measure from the ball center back to the same point on each side of the front axle and see what it is, may be hard to find that exact spot on each side and may be more accurate to remove the wheels and measure ball to center of wheel hub on each side.

Thanks. What is 'ball center'?

[TG Twinkie]

It's the hitch ball coupler. Might be difficult to find the center. Just hook the tape measure to the front of the coupler.

[pcskier]

Originally Posted by TG Twinkie

It's the hitch ball coupler. Might be difficult to find the center. Just hook the tape measure to the front of the coupler.

Thanks. I am taking the wheels off to get metal valve stems installed, so that will make it easier to take these measurements.

[PA BAMBI II]

Literally underlying question...is the frame square? You won't be able to tell that under the bellypan aluminum, etc. Axles squared to an un-square frame still leave you tracking wildly.

[Silver Otter]

We had bad tire wear on our 1999 Classic 30' Excella, too. Took it to Jackson Center and had wheel alignment. Completely fixed the bad tire wear. Worth the expense. It is said that no one else should be permitted to try it. The fixture they use at JC is unique, that's for sure.

[GMFL]

Also need to make sure that you have pulled the trailer in a straight line to remove all flex and torx from the tires. May be better to check with tires off the ground.

[cwf]

With new axles, I measured from spindle to spindle on each side.. they are equal. I then installed tires then used 8foot long fluorescent tubes to ch comas you did. All square. I spun the tires to account for variances.. pretty much equal within about 1/64”... accounting for tire variances.

There is NO SLACK or n the bearings/spindles when rocking the tires when off the ground.

I have heard there have been some of the “no service” axle spindles which have had issues. Even our brand new axles had the bearings preloaded improperly. Perhaps worth checking in your case, too.

According to Airstream there are specs for “toe”... call them.. they are helpful!

[dznf0g]

Originally Posted by cwf

With new axles, I measured from spindle to spindle on each side.. they are equal. I then installed tires then used 8foot long fluorescent tubes to ch comas you did. All square. I spun the tires to account for variances.. pretty much equal within about 1/64”... accounting for tire variances.

There is NO SLACK or n the bearings/spindles when rocking the tires when off the ground.

I have heard there have been some of the “no service” axle spindles which have had issues. Even our brand new axles had the bearings preloaded improperly. Perhaps worth checking in your case, too.

According to Airstream there are specs for “toe”... call them.. they are helpful!

Ok, I haven't read every post, but the only thing that is important is the distance from center of hitch ball to each spindle end. I dont care if frame is square....it can run dog legged all day if the axles are set squared to center of ball. Remove wheels, get a measure to each spindle end.

[TG Twinkie]

I agree with post #10

[Action]

Originally Posted by dznf0g

Ok, I haven't read every post, but the only thing that is important is the distance from center of hitch ball to each spindle end. I dont care if frame is square....it can run dog legged all day if the axles are set squared to center of ball. Remove wheels, get a measure to each spindle end.

If the axles lined up as measures the trailer can not run dog legged. The metal of the frame may not be square however the axle(s) will be perpendicular to the center line axis of the trailer.

>>>>>>>>>>Action

[AlinCal]

The triangulation measurements from ball to spindle is assuming the axle itself is true and not compromised in any way.

More info than you maybe wanted to know here.
http://www.trailer-bodybuilders.com/...mc-manual-and-

[pcskier]

Thanks all. I will do a series of measurements with trailer on jack stands next week when I pull the wheels to install Centramatics and metal valve stems.