Rear Axle Welds

U

ursus

Well-known member
I was given a Model-A rear axle on which a guy had installed 40-42 Ford brakes and welded on plate-steel tube-shock mounts that partially encircle the trumpets at about one foot inboard from the backing plates. The mounts hang down about 6 inches from the axle so would be quite visible from behind. It seems he was part-way into a hot-rod project before deciding that the Model-A ring and pinion wasn't up to handling the V-8 torque. The rear axle was rebuilt with new parts so is a good assembly.

My problem in converting this back to stock is how to remove the shock mounts without damaging the axle trumpets. The welding job was done by a highly skilled person. Can the welds be taken out with a torch or should I labor at it with an angle grinder? I worry about removing any tempering / strength from the tubings, knowing that they carry a lot of tension from the spring and compression from the load. Any thoughts are appreciated!
 
They make 4" cutoff wheels for a 4" right angle grinder. You'll prolly use up a couple but that is what they are for. That is how I would do it. This would keep the heat down. YOu could spray some water on the cuts as you go, would not hurt anything. When they are rough cut off, then put your 24 grit pad on the angle grinder and dress 'em up nice. Shouldn't be too bad a job with the right tools
 
Drain the oil, leave the drain plug out, and also remove the fill plug from the differential. Cut the supports off of the axle housings with an ox-acetylene torch or plasma cutter. You could also use a power saw to cut the supports off. Make the cuts about 1/8" above the axle housings, then grind the remaining metal flush using an angle grinder.
 
Be aware that when welding bracketry etc onto an axle tube the tube will warp. Some guys get away with this on early tubes because they weld all the way around. It sounds like he only welded on part of the axle tube so before you invest any more time into it set the tube flange down on a level and true surface then another level across the top of the end of the axle tube to see if it straight and true.
 
Good ideas so far! I'll check the tubes for straightness. They do look straight on casual inspection. Whoever did the welding was a heck of a welder - almost looks like it was done with of those orbital welding rigs they use on high pressure gas lines.
 
Any time you put heat on an axle housing, it WILL warp.
If you can't fine an unmolested set, go ahead and torch the brackets off like
Bob Bidonde said. Then finish them off smooth.
Now comes the expensive part. You WILL have to have them straightened by someone set up for it. That means 4 gauge plugs to fit the bearing areas. 2 to fit over the outside
surface of the outer axle housing and 2 to fit the carrier bearing areas. They will also have a ground bar to fit through the inner holes of the plugs. With various methods of heat and cooling they will get the bar to turn freely through all 4 plugs. This is the ONLY way to properly straighten a rear end.
People that use weld beads as the heat source to straighten a rear end are Mickey Mouse.
They may get it straight in the end but a weld used for that purpose is a good candidate for a stress riser.
 
How many inches of welding are on each mount?

Any pictures?

I'd just grind off the old welds if they aren't too long.
 
Unless you are experienced with an acetylene cutting torch, use the cut off wheels on a grinder. Better to take a little longer and not make your situation worse.
 
Hey Pete,
Hm, lots of thots here. Wonder how many rodders ever think of it this way , and have ever done anything to address warped housings/trumpets ? BTW...who would a guy look for to fix such warp..what type business, i.e- rear end builder ?

I've got to PM you to ask for specs that you hopefully store re cam. Guy lost my paperwork.
 
a plasma cutter is the best thing to use, they cut fast with very little heat transfer, a rebuilt rear end is worth saving
 
hardtimes said:
Hey Pete,
Hm, lots of thots here. Wonder how many rodders ever think of it this way , and have ever done anything to address warped housings/trumpets ? BTW...who would a guy look for to fix such warp..what type business, i.e- rear end builder ?
Click to expand...

A rear end shop that does high performance work.
Should be several in that general area.
 
Air arc, less heat or no more than the weld that was put on.Also faster than all the other suggestions. If you don't have access to one take it to a welding shop.Just a thought as all the others.
 
The least invasive method is the lowest technology. What is wrong with you ppl. Use a cutoff wheel. Who cares how long it takes ? Is this some kind of race?? Is Martha Stewart gonna do a cover story on whoever cuts their brackets off first??? This project needs NO MORE heat. Does anyone on this forum ever actually think???? Posters should be required to state their qualifications before giving advice which will actually end up harming the project. Ya, I have a plasma cutter, it is an awesome piece of technology, 50K degrees in your hand, and I can plasma cut my neighbors cars in half in 5 min. What is the point here? The housings have already had too much heat, why make it worse. Some of you posters need to come up with other less harmful ways of boosting your testosterone.
 
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hey Bornjohn, a plasma cutter is an air arc, cut off wheels work but to slow and to me a little to dangerous, I had one break and come apart and hit me in the chest, ruined my shirt and caused 4 stitches, my fault cocked the blade and caused it to break
 
I would just replace the rear axle,alot of work and it might be warped,but save it,it might be needed someday
 
I'd still like to see a picture of the welds.

If they aren't too big, there may be no real distortion to the tube and you could just grind them off and be on your way.
 
I would post pictures but am away from home for 2 weeks vacation. The welds actually extend 180 degrees around the tube at a point where there is 4.5 inches of weld on both sides of 1/4 inch steel plate. At this point my only option at hand is the grinder, although the caution about flying chunks of the wheel is a bit scary. I know nothing about a plasma cutter or where I would find anybody with the skills and sense to do the work without ruining the piece. For now I can only sit here on the beach and maybe gnaw on my leg as I worry about this phase of the project!
 
First, anything can happen to any piece of equipment.
Having said that cutoff wheels that distintegrate are usually from not being tightened on the arbor correctly, or one that was allowed to hit the cement on a spin down before it was totally stopped, thus resulting in a small notch out of it. Whammo! next time you use it. Joke's on you
 
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