Axle question

[notned]

My axle has a bend in it. We've been running it. The only noticeable effect is a little tire wear. We've discussed the idea of a chain and a jack to straighten it out. We also talked about pulling the axle which I think that I'd like to avoid.

This trailer was built as off-road, so it's possible that there was one incident with a prior owner which wouldn't be repeated. Off-road isn't our thing.

We think that the axle is 1-1/2" pipe. Leaf springs are involved. The bend is on one side where the hanger/springs are.

You may be able to tell that I barely understand what I'm typing so all ideas are welcome.

I've got to get this in here, a friend helped me with the wheel bearing job. So that's done, I'm feeling good about that.

[eamarquardt]

I think I'd pull it, take it to a shop with a hydraulic press and try and straighten it using a press or heat the axle with an oxy/act torch and try and straighten it. Heating it might be easier. I think I'd bolt or clamp maybe 4 foot straight pieces of angle iron to each hub and measure side to side and diagonally to get the axle as close to straight as possible while rotating the axle so that it is straight in two planes. If you really wanted to be "clever" you could put a deliberate bow in it (the bow should be up) to introduce a bit of camber, but I don't know how much would be optimum.

Hope this helps.

Cheers,

Gus

[madjack]

...MANY axles have an upward bow in their center...if the "bend" you have is not in the center, then you have a damaged axle and need to consider either having it straightened or replaced.......................
madjack

[Steve_Cox]

My axle has a bend in it. We've been running it. The only noticeable effect is a little tire wear. We've discussed the idea of a chain and a jack to straighten it out. We also talked about pulling the axle which I think that I'd like to avoid.

This trailer was built as off-road, so it's possible that there was one incident with a prior owner which wouldn't be repeated. Off-road isn't our thing.

We think that the axle is 1-1/2" pipe. Leaf springs are involved. The bend is on one side where the hanger/springs are.

You may be able to tell that I barely understand what I'm typing so all ideas are welcome

I've got to get this in here, a friend helped me with the wheel bearing job. So that's done, I'm feeling good about that.

Unless you can find a friend to straighten it, a new axle doesn't cost too much. 1 1/2" diameter pipe is probably a 1500# axle and costs about $60-70 at a discount place.

[Yota Bill]

I would not heat it, as that may weaken the steel. I would also not try to straighten it cold using a press, as that may also weaken it and would be very difficult to get it true.
If it were me, I would cut out the stubs, discard the "pipe", get a new piece of tubing, and weld the stubs into that. If you cant do it yourself, a new axle would probably be cheaper and would definatley be easier

[notned]

Ugh... I knew this conversation would go this way. grin

Discount places? I'm familiar with Harbor Freight and Tractor Supply Co.

I didn't think we were that drastic. Could the wheel fall off? I'll try to come back with pictures.

[notned]

I tried to take a picture underneath but the lighting wasn't good.

[John Palmer]

I tried to take a picture underneath but the lighting wasn't good.

Try to picture this.........Place your floor jack under the bend in the axle (hopefully it's bent in the middle)........then place chains under the jack and out around the ends of the axle.........raise the jack and it will pull the axle ends down. If it's bent close to one end, it's harder to bend back with this method because you don't have any leverage. Any "REAL car or truck alignment shop", not the current generation of "computer shops" can do this in twenty minutes.

It's how they have aligned solid front axles for the past hundred years.

[Yota Bill]

the problem with that way is that it will pull on both ends, and could bend the other end first...alignment or frame shops could do it, but they have systems to measure it, and ways of attaching it to a frame rack to pull only where they need to, instead of both ends

[Pete S]

I'm getting pretty good at "warping" little trailer axles back into shape. Some I've bent hauling horse poop for the garden, others came to me bent. After you do one or two you start to really notice all the trailers out there that have bent axles. Scary...

What I do is real similar to what Palmer described. I take it a little at a time so I don't overbend. While I don't recommend that you leave an axle looking like a pretzel I do think the important part is when you are done you should have a little camber and little toe in. The point is to have the tires hit the road like they are supposed to.

It has been working well for me. My trailers track like they are supposed to and I don't get weird tire wear.

Hope that helps.

[doug hodder]

Not to be a trouble maker....but I've built a number of axles by buying stubs and welding them into some sq. tubing...no camber built into it. In the situation of building a fairly light weight trailer it's not as critical as something that is going to have some serious loads on it. More important is aligning the axle ends to the coupler and spring weights. There are lots of trailers running around that are using un-cambered axles in them. In my opinion...1.5" pipe is pretty light, and must have been. An ideal axle would have camber built into it...but it can be done without it. Others opinions, I'm sure, will vary. Doug

[John Palmer]

Doug and Pete "hit it on the nail head".

The important thing is to have it "in alignment". The Toe setting, and havng the axle centerline at 90 degrees to the coupler are the most important items. The camber setting only needs "to be close" for our lightweight trailers IMO.

Think for a minute about the old VW's you have seen driving with swing axles. The lowered ones have excessive negative camber "/ \", and the raised BAJA ones have excessive postive "\ /" camber and they all seem to work OK as long as their toe setting was corrected after the ride height was changed.

If you own, or have access to a frame alignment shop great, you will already know how to take care of your alignment problems. But for the rest of us "home garage builders", here is a simple way to check your toe alignment, and be able to correct it in your garage with a minimum of special tools.

I have two pieces of 2" aluminum angle, about three feet long. The size is not important, but they have to be straight so I use extruded aluminum. I attach them to the sides and the middle of each wheel/tire with a vise grip on a lug nut and a small piece of "all thread" rod. Then measure across the distance to the angle bar in front and behind the wheels/tires and compare the masurement difference. If it's wider in the front it's toe'd out, and wider in the back it's toe'd in. I like zero (straight) on radial tires, to about 1/8" toe in on my "old style" 16" biased ply tires.

So how do you change the toe setting, if it's off. If I desired to increase the "toe in", then I would place a come-a-long around the rear of the frame and give it a pull. But most likely the axle will be stronger than the frame rail and you will need to take a saw-z-all and cut a small (one blade width) slice in the front of the axle to allow the movement. Only cut three fourths of the axle, not all the way through. Pull the axle and release the pressure and remeasure the setting to see your progress. It will "spring back", so you might have to sneek up on it with a couple of tries. Remember, it's like cutting a board "measure twice, cut once". It's easier to pull small amounts two or three times than it is to pull it too far and have to go the other direction. When your happy, just MIG up the cut and your done. The toe setting is very important to check when building a trailing arm torsion axles.

Sorry, I do not have any photos, but it's easy to do, and my pull at any speed with no tire wear or sway.

[John Palmer]

the problem with that way is that it will pull on both ends, and could bend the other end first...alignment or frame shops could do it, but they have systems to measure it, and ways of attaching it to a frame rack to pull only where they need to, instead of both ends

Bill, you can easiy direct "the pull" by where you place the jack under the axle.

[Yota Bill]

the problem with that way is that it will pull on both ends, and could bend the other end first...alignment or frame shops could do it, but they have systems to measure it, and ways of attaching it to a frame rack to pull only where they need to, instead of both ends

Bill, you can easiy direct "the pull" by where you place the jack under the axle.

yes, but you are still relying on the other side of the axle for leverage. Every action has an equal and opposite reaction. I'm not saying it doesnt work, as I have done it myself, but there is still a very good chance that the other end will bend some before the intended side is back into shape, being that it is bent close to one end.

Notned, go ahead and give it a try, you really dont have anything to lose. At this point, the axle needs replaced. If you can fix it without spending any money on it, then your ahead. If you try and cant fix it, you are out nothing but your time.

John Palmer, there is an easier way to check toe, without using the pieces of angle strapped to the tires, and relying on them to be straight. All you need is a couple jackstands to place under the axle (have the tires off the ground) 2 thumbtacks or pushpins, and a tape measure.
Stick the thumbtacks in the tire tread in the center of each tire(does not need to be extremely accurite, eyeball the center and stick it), then rotate the tires so the tack is pointing straight forward, and measure the distance. Now rotate the tires so the tack is facing straight rearward (rotate the tire, do not pull the tack out) and re-measure. The distance between the tacks when facing forward should be slightly less then when facing rearward. How much that difference is is dependant on tire size and toe in desired, but for an average size tire, 1/16 to 1/8 inch or so is OK.
Obviously, since it is an angle being measured, the further away from the center of the hub you get (larger tires, or using the angle you talked about) increases the distance at the rear and decreases the distance at the front (increased differential) without changing the angle (toe) at all. That does mean that getting further away from the axle centerline makes for a more accurite measurement, but it is still a "best guess" as to how much is needed. Camber can be measured the same way, as long as there is nothing in the way of measureing across the top of the axle.

[angib]

More important is aligning the axle ends to the coupler...

I would argue that this isn't very important either - all that happens if this is wrong is that the trailer tows 1" out of line with the tow vehicle. The continual side thrust will wear out the wheel bearings a bit earlier, so you may get only 90,000 miles from them instead of 100,000.

Check a few of those boat trailers with an axle that can be moved forwards and backwards to balance the load - their axles are never perfectly in line with the coupler but they get towed tens of thousands of miles with no problem.

With most trailer issues, I reckon if you can't see the problem, but have to measure to find it, there isn't a problem. Trailers are at least one whole level of technology less sensitve to geometry than cars/trucks.