Did a bit of welding on a Chrysler 8.25 rear axle housing (perches, brackets, etc) It warped, I could SEE it with my eye when I looked through the tubes, end to end (empty housing). I scrounged up a 1.25" Ground and polished steel bar and checked it on V blocks, then ordered "pucks" for the carrier bearing saddles. The bar showed I was off center a good 1/4" on each axle tube end. I got an I beam and welded up 2 HD screw jack stand, 12 ton bottle jack, chain. I was easily able get the tube straight WHEN I had pressure with the jack but it would flex back when The jack was released. So I heated and cooled the opposite side and it pulled it almost true. I have been chasing the last 2-3 thousands of an inch around for an hour. My measurements are 2-3 thousands different on opposite sides of the bar, so the bar is 1 - 1.5 thousands from being centered,, Close enough ?? Roller bearings BTW.
When I worked on the production line running 9-inch rear axle housings through the automated welder, the guy at the end of the line straightening the axles didn't get them as close as you did. I think you're good.
Just repaired this 12 bolt out of a 69 C*m*ro, it was off about an 1/8 on each side and had 92000 miles on it and no issues. Other than having torn off a spring perch….
The number of OEM axle housings that have crossed my bench is enumerable. The number that I found to be straight enough to slide all of the pucks right in is probably about 6.
Thanks for all the advice and allowing me to "Tap the brain trust" I picked up a 10x6 I beam at the local scrap yard for ~ $40 I had the shoring screw jack threads/handles and the 2" pipe lying around. I did not use pucks on the outer ends, but used a digital micrometer to check clearance between the 1.25" rod and inside of the axle tube. The final image is "good" after releasing the jack pressure
You only paid $40 for that I-beam????? It musta been a few years ago because you couldn't even look at it now for that price. Nice rig BTW.
It was about a month ago. I looked for a week, called a few steel yards and erectors looking for "cut offs" or scrap. I wanted a 10" High by 6-8" wide piece, 6 foot long. Closest I could find was a cut off (scrap) of 8" high for $180, or a custom cut from stock length of 10" high for $240 By chance I stopped in a somewhat industrial recycler,, Was pretty sure they did not sell small quantities to the general public. (This is a big operation) They guy at the scale house told me to go see the guy with the torch out back,, they had piles of I beams, 10-20' pieces of what I needed, they cut it to length and help load it in my work van. I loaded a few short pieces of angle, square tube, round tube, plate. Weighed out and the owner told me $50 for everything. I have been back a few more times.
Correction!! I did NOT get it within 2 One Thousands,, I got it to 2.5 ONE HUNDREDTHS. Long hours, old mind
My experience is if you can push the axle/sealed bearing into the housing by hand it's straight enough. If you have to drive it in more than about 1/8", you'll have issues with poor bearing life.
Many moons ago things got slow in my shop one summer so a friend, Levy Jones, maker of various Indy race car parts, asked me if I could come over and help him out for a few hours a day for a couple of months. He had a contract with Penske Racing to build 9 inch Ford rear ends for their road racing cars. After showing me the prints and going through the process on one, he turned me loose on one. The axle ends and brackets were already on hand and machined to size. All I had to do was assemble and weld all the stuff together. Beside the new tube ends there were various suspension related brackets and strengthening gussets to be welded on. All of this welding caused the housing to warp in many wierd directions. Previously I had had quite a bit of experience straightening cranks, cams and various large rolling mill rollers so wasn't a stranger to straightening stuff with a torch and a hose, but this was a whole new world. I spent 4 hours getting the first rear end straight. We used a plug in each carrier bearing bore and a plug in each outer axle bearing bore. The test bar had to slide and turn through all 4 at once absolutely free when done. This meant no more than .001 bend anywhere. While this was an all out unlimited money effort, I am sure if you could just get the test bar in with some effort it would run forever on the street.
At 25 thou, I’d just run the dang thing. If you want a wake up call, take it all apart and check it 20k miles later I’d been driving a pickup as a daily for 6/7 years, it was a good 10 years old when I got it. Had to change the shocks, so jacked it up under the third member and noticed both axle tubes moving. Up/down a few times and I could see the plug welds in the housing to the axles we’re not “as one” anymore. I semi centered it and filled it. If I could see movement at the 3rd member to housing, imagine what it would have been 2.5 feet away. PU only had maybe 160k on it when I sold it.
I made a thin slice through the gusset (truss) on each side prior to "straightening" the tube. When I re-welded the truss web and cord it pulled it 2.5/100 out.
With the bearing back in the end,, the axle slides in and engages the splines like butter, Once I engaged the splines I can push it in with my pinky,, I'm calling it good
Some drag guys used to strive for a little toe in at the front, about .100 on a full length rear axle. The thinking was it would be straining to straight under load, less resistance. Makes sense. As was said above, if it assembles by hand, no hammers, let it eat.
Guess which way axle tubes will bend on a drag car? Winner gets an all expense paid trip to Disney world as an apprentice Mickey Mouse suit drycleaning assistant.
Yeah. So if a cambered rearend is legal you run two-piece drive flanges. If not legal you run aluminum drive flanges so they're the wear point. If you have to run steel drive flanges you chamfer the axle splines so they have room to rock. < Picture the ball end on an allen wrench.
Yup, splines on a curve! It does create wear potential at the spline, though. Standard tube camber is up to 2.5º, which is pretty "off" of straight.
My car will bend the left tube forward more than the right. Every time it gets straightened it bends easier the next time so I build another housing with thicker tubes and more bracing.
Here's how I made a bar and pucks to check my rear. I used a piece of 1 1/4" galvanized fence post. I filed down the welded seam and polished it with 80 and then 220 grit. Checking for straightness. Straightening tools Needed the mallet to straighten it. Could crank down on the clamp until the fence post almost hit the bench with no change. Amazing amount of spring back. Tool for making the pucks, no lathe. The object here is to have the outside and inside diameters of the pucks concentric. The top piece of 2x4 pivots on the bolt sticking up in the upper right. The puck holder is a piece of the fence post pushed into the 2x4 half way between the pivot and the adjuster bolt. The adjuster bolt is 1/4x20. That means 20 revolutions will move it 1". A micrometer turns 40 times to an inch, hence putting the puck holder half way between the pivot and the adjuster allows measurable movements by the .001". For the scale, theoretically a 2" diameter should have worked. (2" x 3.14 = 6.280 : 1/4" x 25 = 6.250, Not perfect but workable for this.) I actually had to go to a 2 1/32' diameter. The adjuster threads through a drilled and tapped scrap of 1/4" steel. I lightly buggered the threads to provide some resistance to turning. The finish nail is the pointer. The rubber band keeps tension against the adjuster and pivot piece. The corner of the 2x4 is cut away so I would have a sharp edge to read the scale off of. When I drilled the holes for the center of the pucks I used a hole saw, but that left the holes a little large. I was able to correct that with aluminum coil stock sleeves. That didn't work out for the pucks in the carrier, so I remade them out of 2x4 and used a spade bit to drill the center holes. Those were a little tight, but a few strokes with some worn out 40 grit wrapped around a 1" pipe fixed that. Should have made the base longer, I could have clamped it on the deck closer to the belt. Would have made keeping things parallel easier. When I bolted the pucks into the carrier I had the fence post through them to keep them in alignment. While this isn't the most precise set up, I figure if you can rotate the fence post in 90* increments and the pucks still go in the end of the axle and rotate freely, you've got to be close enough to OK. One thing i learned is if you are using heat to straighten the axle, it is best to slide the fence post out. Measured within a 1/16" front to back and top to bottom, also after rotating the tires some.
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