Narrowing a Columbia rear

[uncle buck]

Had a successful weekend in the shop narrowing a 1942-49
Columbia housing and splicing it with a 1933 34 housing.
A friend and I have been thinking of doing this for a while
To install in my 1932 pickup and made fixtures to jig it up.
The bar spins smoother in the narrowed housing than it did
in the original, so I feel we have successfully done it

[FritzJr]

Thank you for the pictures, but I would like to have a description of what you needed to do for this conversion. I am assuming that you used the end of the 32-34 housing and welded it to the Columbia housing.

[uncle buck]

Basically we first obtained a 60" x 1.5" straight machine steel to hold things straight . Then we machined 2 pieces of aluminum to fit in the place of the carrier bearing races and bored them to the shaft diameter of 1.5" and honed them to smoothly slip fit the shaft. We then machined one end of the shaft down to fit the i.d. of the axle bearing end 3" long to slip fit the full length of the bearing end. The cut off bell end was kept to bolt to the driver side of banjo and hold one of the aluminum slugs. We used two 1.5" locking collars to hold the slugs in place. That pretty much was our tooling used. We then measured our needed passenger side length using the stock one we were replacing. We then bolted the Columbia tube to the Columbia cast adapter and compared the tube diameters to determine where would be best to cut and splice. We made the cut on the Columbia first and then set it up on a milling machine to cut it completely flat and level to give us an accurate measuring point. Then we cleaned up the inside to get a clean press slip fit. We then marked the donor we needed at the length it needed to be and also 1.5" longer. We chucked that tube up in a lathe and turned the tube down between our marks to give us a tight press fit and made the parting cut. We then bolted the driver side and the Columbia bells to the banjo so we could properly clock and index the 2 halves together using the spring perch points as reference. We then aligned the markings and pressed the 2 pieces together and double checked for our needed length - which was right on. We reassembled our fixture pieces and bolted the Columbia end back on and checked our fit. The shaft turned by hand as we needed to show we were straight. We welded it all together skipping sides while continuing to make sure the shaft didn't bind and let it cool. The shaft spins even easier now that we are done. That's basically what we did , right , wrong , or not..... it worked

[cdan34]

The welding looks good. I've done this before and noticed on the rear end housing when there is welding, just a little can throw the assembly off center.
So to check this I think the best way is use a lathe. I my case, I checked mine after welding and found the housing to far out. To bring it back to tolerance I welded a small amount on the opposite side. This was done while in the lathe, between centers, on bearing surfaces and both the flange surface and bearing area indicated fine.

Good luck.

[jimTN]

If you are using the later center housing then of course the drive shaft will have to be shortened and for a 32-4, spring hangers changed. With the 41 and earlier housings you can make a jig for the curved spring hangers , cut a set of them off earlier housings and then weld them to the later housings across the later spring mounts. Around here we just change the one side (Columbia), use the 34 center housing or late 32, use a stock driveshaft and torque tube and a spacer plate between the 34 center and later Columbia housing that has a 34 outside housing grafted to it.

[uncle buck]

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Originally Posted by cdan34

The welding looks good. I've done this before and noticed on the rear end housing when there is welding, just a little can throw the assembly off center.
So to check this I think the best way is use a lathe. I my case, I checked mine after welding and found the housing to far out. To bring it back to tolerance I welded a small amount on the opposite side. This was done while in the lathe, between centers, on bearing surfaces and both the flange surface and bearing area indicated fine.

Good luck.

Thanks cdan,
Good info there. Fortunately we feel pretty confident on it being straight. The friend helping has been in the transmission and differential business for over 50 years and been narrowing 8" , 9" and 12 bolt /Dana rear ends since the 70's. I have seen him use your method straightening before on them and it does work great.

[uncle buck]

Originally Posted by jimTN

Around here we just change the one side (Columbia), use the 34 center housing or late 32, use a stock driveshaft and torque tube and a spacer plate between the 34 center and later Columbia housing that has a 34 outside housing grafted to it.

Thanks Jim,
That's essentially what we are doing. To retain the stock curved spring , I am using a 33-34 rear including the narrower center and spacer. Since my truck has an early rear end the driveshaft from it won't work. With the 32 wheel base being shorter I will need a driveshaft and I do have the 33-34 driveshaft and torque tube to shorten.

[PeteVS]

Rotated some of the images. I just can't think straight otherwise.

[jimTN]

Sounds like a winner. The early 32-6 hollow drive shafts are easy to shorten, just turn off the weld at the coupling piece, take out what you need on the tube, drive them back together and weld.

[uncle buck]

That's the plan. Fortunately he has a lathe with about an 8' bed and has shortened a lot of driveshafts