Rear end shortening question

I hope how I am asking this question makes sense. When shortening a rear end, is it O.K. to cut a pre-determined length of tube out of each side inboard of the housing ends (leaving a length of tubing attached to the housing ends) and then weld the tubes back together thus reusing the orignal housing ends or is it better to cut the housing ends off and then cut off the required amount of tube on each side and then weld new ends on? The reason I ask is that I have been researching the topic and it seems most of what I have found is the method of cutting the ends off, shortening the tubes and then welding new ends on. When I had my rear end shortened however, the fabricator just cut out a section of tube on each side and then welded the tubes back together keeping the original housing ends intact. I am just trying to reassure myself that the way he did it is safe and I won't have any problems in the future.

It is normal to cut the ends off and weld new ones on at the correct length.

That said, there are lots of ways to skin a cat. It comes down to weld quality. Full strength pipe welds are an art. I would not try it myself but know a few folks who can do it. What do you know about the welder? Has he done this before and how did it work out? If there are customers out there who run hard without problem that is a re-assurance.

I've done it and rewelded the ends on a 9".Make sure the cuts are square and check and recheck when burning them back on.This was in a drag car and never had a issue.I used the old axles cut off with a piece of correct ID pipe slid over them to keep the ends square when welding.

Did he cut the housing at the ends and remove some to shorten it or did he cut it in the middle of the axles tubes and remove a peice and reweld the tubes back together If he welded the middle back together I would be suspect of that

I hope its backbraced if it was done as Cab says..

I'm right in the middle of doing this. For a circle burner that dont need to be perfect but I want it as perfect as I can get it. I was not comfortable with paying Moser 3 bills to shorten the housing. I cut 3&1/8" out of the middle on each side. 2 questions: (1) what is the best sander/tool to make sure the cut ends are square (they ain't now) and (2) what is the best way to make sure the housing tubes are aligned when my welder starts on it? Please advise. Moser did shorten/respline the axles for me.

The words " Rear end" and "shortening" just sound perverted....

I prefer " narrowing"

I have done it both ways to Dana 60s, but I did not do the welding. The Ramcharger got both tubes cut and new Big Ford "Torino" bearing housings because my racer is using a Dr. Diff spool, 35 spline Dutchman axles and Ford 11" drum brakes. The ends are chamfered to aid in the welding. The Dana 60-2 that I did for the D100 had only one tube cut and the axle shortened and resplined. The original end for the drivers side was cut off, chucked in a lathe and chamfered. The Dana 60-2 uses tapered wheel bearings like the 8.75", but the ends have 6 bolts to bolt on the brake backing plate and are perfectly round, so they fit the jaws of a lathe. The 4x4 shop that did the job uses a high power Mig welder in "Dual-Shield" mode (gas shield + flux)with great penetration and the normal jig for alignment. These guys do this stuff all the time at www.oly4x4.com. There is probably a shop in your area that can do it too.

Pete do you have a suggestion for squaring up the ends that will get me pretty close. I hate to pay for lathe time on this low buck deal. EDIT Pete I just read your response in the other rear end thread. Well I am committed to where I am at the moment on this deal & I think if I can get the ends squared I'll be OK

"Did he cut the housing at the ends and remove some to shorten it or did he cut it in the middle of the axles tubes and remove a peice and reweld the tubes back together"

I tried to describe what he did in the next to the last sentence in my original post. He cut the tubes in the middle and then welded the tubes back together. Here are a couple of pics of the weld. This is the passenger side.

Driver side.

I would, and do, check the ends for straightness by having a helper and I use two steel carpenter squares and measure 16 inches out from the housing ends, front and back and then straight up and straight down If there is more than 1/8 inch differences in widths then you should have the housing straightened The roundy round racers like to see 1/8 toe in on the front sides, not toe out They say the housing will bow backwards under hard acceleration Maybe there talking about stock Ford housings, you think

The welds in the picture look very good, I wouldn't be inclined to worry about them. My reasoning is they look like the welds of a professional who would have made sure to properly configure the ends and the welding process to assure complete penetration.

If you could look inside the tubes to the weld zone it'd make the picture complete. I'd like to see penetration right to the inner surface.

Those welds probably have a tensile strength of 70,000 psi and are as strong or stronger than the parent metal. They are also pretty close to the ends of the tube, so that minimizes the moment (bending force) they have to resist. IMHO as long as the penetration is good, no need to do anything to the welds except paint them and install the axles, drive the car.

Note: This says nothing about the alignment and/or any distortion caused by the welding operation.

R.

I tried to take pictures of the inside of the tubes but most kept coming out blurry or dark. But I did get this one. The seams inside both tubes are discolored all the way around and in some spots there is some weld bead showing like you see in this picture. The fabricator did have the housing set up on a jig and he had a shaft the diameter of the tubes inner diameter run through it to keep the tubes in alignment.

mine are 'narrowed ' just like 440mopar has his. i had them done at speed shop along with the axles and they were done on a lathe so the cut was square to begin with.

Moser did mine just like your pictures. Once the ends are cut they are beveled and mounted in their jig and then welded. A machine rotates the rear end so the feed and speed are correct and duplicated on every weld.

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I would, and do, check the ends for straightness by having a helper and I use two steel carpenter squares and measure 16 inches out from the housing ends, front and back and then straight up and straight down

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Thanks Cab. I have a bench belt sander with a vertical face round disc attachment on the side. I'll see if I can feed the housing ends in horizontle to it to square em up