The Stovebolt Site Forums The Shop Area Engine Shop Staight axle bent?

I am installing new king pins in my 46 1/2 ton,and I have the axle tore down as I am going to sand blast it also.I had the axle turned upside down and I noticed looking down one end to the other,That the staight axel looks like it takes on a slow twist .I have never drove this truck as was not in running condition when I got it I was looking for a project truck .I have owned other trucks with staight axles but never noticed them having a twist like this.Is this normal or do I have a bent straight axle?
Thanks for your advice.
Jim

It sounds like you have a bent axle. Most likely it was bent on a field or dirt road when it hit a large rock. There are places that could straighten it, or now would be a good time to think a bout that dropped front axle.

John

The axle could be bent, but it is really hard to tell for sure without measuring for sure. When I am in doubt a beam, I use one of these http://www.wheel-a-matic.com/page11.html I lay the beam on its side and stick the gauge to the bearing area of the king pin bore. I adjust the axle to where one side reads 0. I then measure the angle on the other side. A degree or 2 won't hurt anything. If I find a twisted beam on a salvage truck I bought, I throw it away because they are plentiful. However, on a 50 year old vehicle it might be worth your while to straighten it. It doesn't take much to bend an axle, but it takes a steady hydraulic push.

Some times when we used to do the caster on sold axle trucks we twisted the axle if we could not get it with shims or one side was at spec and the other was wat out,same for camber. I would bolt it back in and see what the angle comes to laying a degree wheel on the top of the pin hole. You'll get a fairly acurate reading on if its twisted or bent beyond an alingment twist. If you have a spring shop in your area they should be able to bring it back to spec if its out

When I checked my axle I set the beam up dead level in a vise with a spirit level across the two spring pads side to side. Then I checked both spring pads with an angle gauge front to back -the angle should be the same or close here if the axle is straight. Then I put the kingpins in the axle eyes so that most of the kingpin was sticking out the top of the eyes and checked the angles of these with an angle gauge. Two measurements here - front to back; this the axle castor -The king pins should be at 90 degrees to the spring pad forward and back measurement (the on-the-road castor is set by the spring wedges). Side to side measurement; this is the king pin inclination which will set the camber when the spindles are fitted -can't remember what angle this should be, but it should be the same both sides or within 1/2 degree or so.

Stuart.

I decided to go ahead and order a 3 inch drop axel from Sid.I would like to use the stock springs and take a couple leafs out but have never done that .How many leafs can you take out with out it being a safety concern?Since the rebound clips are riveted on would it be best to grind the rivit off and go back with new rebound clips?
Thanks again for your help
Jim