I want to narrow a couple rearend housing I have. I have a general understanding of how to do this. I have seen the fixture for sale on Ebay. It includes the donuts that go into the 4 bearing locations and then the long straight rod run through them for alignment. I would like to hear from you who have done it. Did you make your own fixture? Once welded, does it need to be straightened? Thanks-
Have helped do this twice in my high school shop cl***. If your good with a lathe all u have to do is make 4 aluminum pieces to fit in the bearing locations with a large hole in the middle to slide a big solid steal pipe through to keep it all straight then weld it up. bevel the edges you will be welding in the lathe for better penetration and fit.
I am waiting for an expert to come on, and explain how to do this operation also. I have put the straight bar in to get everything square and tack everything in place. Then welded flanges and mounts on without the straight shaft, everything warped out of shape. Tried another one with weld a little and let cool down, and weld some more, with the shaft bar left in. THEN could not get the shaft out of the project. Still had to straighten both ***emblies to some extent when done with the welding process. Maybe weld slower and more cool down time between welds? Maybe smacking the welded area with the hammer to set the metal, after welding. Waiting for expert advice also.
i am gonna purchase a jig either from mittler bros or ch***is works has anyone used both and have a preferance???
You weld all brackets on before welding on the bearing ends. The ends should be flush mount so they can float in relation to the axle tube. If your housing is warped badly in the beginning from prior work, you'll have trouble. The housing tube ends need to be cut perpendicular to the line up shaft to avoid warping. You need almost no gaps to fill on the bearing holders. Any gaps allow movement.
I cut up and welded a number of 9 inches. two ways I did it was using 8 inch tubs in a 9 inch. Just cut the 8 inch tubs about 12 inch and fit them into the 9 inch housing. The out side of a 8 inch tub is the same diameter as the inside of a 9 inch tubs. All I did then was bolt the rear end together and took my time welding. The other way was to cut the tub to length less the bearing ends and cut the weld on the bearing end but not to cut right through. There is a sleeve on the bearing ends that goes inside the housing. You would do a better job is you had a lath but I have done it free hand, tricky but can be done. All I did then was tap the bearing ends into the housing and again bolted the rear end together then took my time welding. Heat is a big problem if you add too much heat to one place it will warp. Hackerbill has told me that he pre heats the housing before welding and that way all your welds cool at the same rate, Never did it this way but make a lot of sense. As you weld you housing there is a shock factor happening and this is where you warp your housing. Me I worked around this by only welding ever 2 inch and moving my weld from side to side, letting it cool.
When welding the ends turn the shaft. If it gets hard to turn weld in a different spot to pull it in the other direction.Thats how I do it anyway.
Yeah Fitzee...slipping the 8" tubes into the 9" tubes worked neat. There was a cut off year where the earlier (I think!) 9" tubes were too tight for it to work so I had a gauge made to identify the correct housings without pulling them apart. Did a few like that. It adds a little weight...but once you have the tubes slipped together and welded (with preheating) I found that I could add the 4 link bracketry from the original rear axles without much worry of warpage. The inner tube helped hold the outer tube in alignment as the brackets were attached to it! We were running stock Maverick or Grenada axles, but could upgrade to aftermarket of course... Heres a pic of Mikes Vega. It has a slip-fit housing. You can see the joint right above the traction bar where the outer bracket attaches. (The joint LOOKS like the outer housing must be an INCH thick but it isn't...thats just a shadow!!! The housing is 1/4" tube and you can blend it in to look like a stock pinched housing with no problem. The line on the UPPER half of the housing gives a better idea.) All that lead...well...that was just for ballast!!!! Hahaha
I have done a bunch of these over the years (sorry, no pics). The one critical thing no one has mentioned so far is that the heat affected area, the area around the welds, needs to be normalized. After all the welding is done and, after making certain that the inserts that fit into the bearing ends have not moved, take a rosebud and slowly heat the area around the ENTIRE cir***ferance about 3 inches each side of the weld until it is dull red....no, not cherry red; very dull red. Then let the area AIR cool. Don't touch it or move it or remove ant fixturing device until it's cool. This process takes all the stresses you've introduced into the housing by welding out. Since I started normalizing the area around the weld...never had a problem.
Yup! Agree 100%! Preheat...weld...post heat. Everything cools slowly and evenly...which cuts down on the problems you might have, and just might leave you with NO problems at all!
I have done hundreds of rear ends-8",9", 10 and 12 bolt, Dana 60's and anything else you can think of. You will need a jig. Mittler Brothers, Ch***is Engineering and others have good ones. You will also need to know how to measure, as sometimes you have a non centered pinion housing that you want to turn into a centered pinion housing or vice versa. 9 out of 10 rear ends housings that I work on will need at least one tube straightened before you can narrow the housing. I straighten the housing before I make the cuts, and then again after I make the housing cuts. I tack weld the housing end on in four places and weld. I leave the housing jig in place when I weld any brackets on ansd there is very minimal warpage that can be straightened one final time.
One word of caution. It may be cheaper to get a different wider axle to shorten so that the axles can re economically resplined instead of having to buy new expensive axles. Lucky for me I called Moser with questions first. I had all my measurements. He recommended starting with a wide Torino rear. I never would have started with a rear that wide until I talked with him. That meant that I could send him the Torino axles to be resplined. Much cheaper than buying complete new axles. It doesn't cost any more to cut the tubes of a wide rear than it does to take a little out of a narrower axle tube. Getting the correct length axle to go into it can be a costly exercise. Planning ahead can save some cash. It did for me anyway.
"9 out of 10 rear ends housings that I work on will need at least one tube straightened before you can narrow the housing." I agree that if your doing this as a profession then a jig is a great idea! Or if your less than sure of what your doing...or have someone close WITH a jig then its a good idea to use one. Why not? You know your gonna be DEAD ON when you use a jig! But for a guy in the sticks...or someone with a single axle to fab...or just no bucks to spring for something that they might only use twice in their lifetime? I don't believe they should be discouraged. You learn by doing. YES, you might screw up. BUT it's metal...it can be fixed or even replaced. None of the rearends I put together EVER had bearing or dog tracking issues. NONE. Some of them I had in sight for years and years, so it wasn't a case of out of sight, out of mind either! This is a close knit community of gearheads up here. The Vega was used by my friend for at least 7 years before he sold it. NO issues! I was careful...as you must be. It isn't a job for someone who just doesn't give a ****. The question that begs asking is a simple one: Those 9 rearends out of 10 that needed straightening BEFORE you even touched them? Wouldn't THEY have remained on the road indefinately as they were? Sure they would...because theres a SLIGHT allowance for misalignment that bearings/seals/splines can handle. Surely you don't think the Ford factory is within .001 with every rearend it ever put out!?!? If you have access to a jig...use it...its a good tool and it WILL do you right every time...once you figure out the procedure. A bit of common sense, well placed/timed heat and a straight edge will work well too... Someone has a signature on here that says something like... "No matter if you think you can or you think you can't...either way, your RIGHT. It's all about at***ude."
Maddog, I've had Cook's Machine in East LA straighten and narrow rearend housings since the early '60s. Unless you are setting up to modify a number of housings it probably would be better to have them do it for you. Their number is 323-268-6571, located at 4845 Telegraph Road. Cook's is the only machine shop that Tom's Differentials would recommend for drag cars. Talk to Jim or Paul. The FOGGER
yes, some things it's just easier and you get better results if you take it to a pro...the guy i use charges $50 a side
Thanks for all the info. The best advice may be to let a pro do it. I have a whole car to build, maybe I shouldnt take narrowing a rearend on too.
The Jalopy Journal
