Straightening a bent axle housing

I have a 68-70 B-body Dana 60 axle housing that was raced and spent some time under a Camaro. I'm building it to put under my 69 road runner.

When I installed my D60 narrowing fixture I found that one of the tubes is bent such that the bearing housing is about 1/8" out of alignment with the carrier bearings. I heated and quenched the tube but this had zero effect. The next attempt will involve the careful use of a press to straighten it.

Question: is there a tolerance associated with axle housing straightness? Or does any amount of misalignment cause excessive bearing and tire wear, unacceptable axle shaft sideloads, and a car that tracks or launches poorly?

Thanks!

You do NOT want the rear axle to steer the car.
Use a bar slid through the axle end-to-end to know it's dead straight.

I know several chassis shops that straighten Dana and other housing by heating small places on the axle tubes near the housings(1 to 3.0 inches out from the edge of the housing) and then quenching them with water soak rags until they get it straight enough for them to use,
Try again and don't quit
I use a pair of carpenter squares laid onto the bolts that the bolts that hold the backing plates onto the housing and then measure 15.0 inches out from the center of the housing to the end and then to the other square held on the other side to see how much toe in or toe out they have, same thing up and down also
You can use two nuts with large diameter flat washers to hold the squares up against the axle flanges I shoot for no more than 1/8 inch toe in on the front side towards the front bumper
Let us know what you do and how you do it once you get it fixed please

Topside: 10-4, I figured the housing had to be straight as possible.

Cab, are you saying apply heat 1-3" away from the center casting? I was applying heat in the center of the tube (half way between the center casting and the bearing end. I have a Mark Williams narrowing fixture I'm using to check straightness. It is a 2.5" precision ground bar with three steel bushings. Two bushings locate in the carrier bearing saddles and the other slides into the axle bearing housing.

I haven't done a Dana . But I did do an 8 3/4". Heated and quenched about where the perches would go. You could watch the tube move the wrong way when heated. Then move back when cooled. However the Dana tube is much thicker. I'll bet it would take a ton of heat. My bet is 1/8" probably won't hurt anything. Now if it had toe in/out that would be different. Bolt some straight stock (center a 3 foot piece) to the housing flanges and measure the difference at the front vs the rear. That'll tell you what the toe is. You could always cut the end off if its bad enough and reweld it on in the exact spot. Measure it first and see.
Doug

I'm wondering if a bead of weld could be placed longitudinally on the tube? I know stuff always moves when welded that you DON'T want to move

Southwick machine Colona IL 1-309- 949- 2868 straighten axles all the time [stock car, demo car, big ford ends on TR-6 road race car's, ship those all over the world ] never seen them use heat ,just the centering bar and a big press they even will replace tubes in dana's if you need.

Yep, that's the trick...more heat on a larger area close to the center before quenching. You want the housing as close to dead straight as possible or you can have premature axle bearing and spline wear.

I'll keep everyone posted on this. I burned a lot of acetylene trying to heat and quench the tube to no avail so I'm going to try the press next. I ordered a large Vee block to try to avoid crimping the tube. My plan is to go slow and see how the tube reacts to the pressure. I figure I'll probably wind up having to push it slightly beyond straight and let it spring back. I can also use the torch in combination with the press if need be. I don't want to create a larger problem than I already have!

Two rules when straightening with a torch.

1) Heat where the bend is.
2) Heat on the long side of the bend. The bend should get worse with heat and when quenched will move to get better.

Our mechanics straightened 10" vertical pump shafts with a torch and a rag in a water bucket.

6pakbee, I did it exactly like that. I clearly wasn't able to get enough heat in the tube with my large rosebud to move the tube. It didn't budge during heating or quenching. I made six attempts with zero results. I could only get a 2-3" area of the tube to a very dull red color.

Then you have done all you can do with what you have using that technique.

Don't use a rosebud to heat the tube, use a cutting torch, heat and make a 1/2 inch wide band about 1/2 way around the tube, as this cools, gently heat
the other side of the tube, this allows the tube to shrink on one side aided by expansion on the other side.

We straighten axle housings in-house. A large press, line bar and holding fixture is what we use. They are all done cold. Here's a couple pic's of before and after. Good luck on your project!

I have a bent trailer axle and have been unable to find a replacement, guess I will be taking it out and trying some of these techniques...

Make darn sure your "bent" trailer axle isn't by design.

that's how i have done it.
also use that method when narrowing the rear housing. i use two support slugs for the bar at the differential bearing locations as well, so everything is in the proper location.
doing it this way insures axles will slide in without effort.
one would be surprised just how off a factory axle housing can be at the ends, and still function just fine.......

I was able to make progress with an I beam, bottle jack, and a chain.

i have done that before as well, when a shop press wasn't available.
still used the solid bar and alignment pucks for the ends, with bearing bucks bolted to the differential where the bar passes through.
it still amazes me just how far off an original, unmolested housing can be as far as outer bearing ends are in alignment, and still have very long bearing life.

how far off were you Joel ?

Before and after:

I made a heavy duty work stand to straighten rear ends and shorten them. To straighten them I use a 1.5" tri bar run thru the housing with bushings where the bearings are. Working on one end I slide the bushing out and use a hyd jack to move the housing where the bushing will side in. This takes some time to get just rite. When I shorten a rear end I make sure the ends are square as I'm welding them. After all the welding is done I straighten the housing. I have rebuilt and straightened several rear ends and only one housing did not need straightening.

Convx4, that is a really nice jig! I’m embarrassed to show the makeshift jig I cobbled together.

But it worked.

I used a 20 ton bottle jack and a torch to straighten the D60 tubes. Now I need to cut one housing end off and weld a Moser end on. The bearing bore diameter of the Moser ends are too tight to slide a bearing race so I’ll have to address that before welding them on.

Thanks for all the input and recommendations.