Straightening a trailer axle

[Bert_]

I have a little trailer that I had put some ag spindles on but wasn't really happy with the size of the bearings. So I found this 7,000lb torsion axle that the guy said might be bent. Has good bearings, good brakes so I paid the guy $250 and took a chance.

I put a 20" straight edge on each hub. It measured 3/8" toed out. So it's definitely bent.

Pretty sure I can straighten it. Here is my rig.

 

[y'sguy]

Well I guess? Curious to find out how it goes. Most of all, how do you check it for accuracy? Also in my experience axles can be bent way out on the end of spindle.

 

[cannuck]

I would expect the spindles to be bent, not the trailing arms. Oops - already mentioned, but I concurr.

 

[jack stand]

If it's got "some miles" on it the rubber that supplies the torsion action could simply be worn out.
It was replaced for a reason BUT I'm not positive that would necessarily result in your alignment problem.

 

[Bert_]

The tires are toed out, the bend is parallel with the trailing arms. I think that makes it reasonable to assume it's bent at the shaft where it goes into the rubber. Plus I can visually look at the gap between the trailing arm and the axle tube and see that it is not consistent all the way around.

The trailing arms put a ton of leverage on that relatively small shaft. I've never bent one permanently but I have watched how much they will deflect on a tandem axle trailer in a sharp turn with a load on it. I think that's how most get bent. Load them up close to capacity and make a sharp turn on pavement.

I'm going to use this one as a single axle so it won't have that problem anymore.

 

[Bert_]

This thing still has all the paint on it. It's off a seed tender trailer probably 5-7 years old. Been parked in a shed all but one month a year. I guarantee it has less than 10,000 miles.

These axles are about $1200 new. I figure worse case I pull the hubs and backing plates and still have more than $250 worth.

 

[Bert_]

I pushed it with the jack. It took quite a bit of force. Enough that I made sure not to stand in the path of the jack or anything else if it decided to come flying out. I used a 12 ton jack and would not have wanted a smaller one.

Using a 20" straight edge on the hubs it now measures about 1/16 toed in. I checked the camber and it's within an 1/8"

 

[Bert_]

This is how I kept from pushing the shaft out of the rubber springs. As far as I can tell, nothing holds it together except a tight fit.

 

[jack stand]

I always wondered what/if they're retained.
Seems like you did a great job bringing it back to a good toe in.
Would you know if perfect new trailer axles come exactly parallel or is a teeny bit of toe in desired for tracking?

 

[Ole Slewfoot]

They come with more crown than toe.