My shortened torque tube is binding up. Does shorting the torque tube change the geometry? Is my new center bearing misaligned? Or considering the torque tube is shortened should I not run a center bearing at all?
I had one in a '32 coupe that had been shortened in the 1950s and the car never driven much after that. I went through everything to get it back going and twisted the driveshaft in a few hundred miles. Turns out the torque tube bent when it drew up while cooling from welding the radius rod lug back on, at least that's where it was bent. It didn't have to move much to get it out of line and then create a whipping in the driveshaft which overheated the metal at where it was flexing and caused metal fatigue. Mine did not have a center bearing and had a hollow '32 style shaft. To remedy the situation, we shortened another torque tube and securely clamped it in an improvised fixture on a platen table. No problems with that one. I never thought welding a radius rod bung on one could cause that much of a problem, but the driveshaft has to run true or it will flex and fail.
Randy, I am going to be doing this. I never thought about distortion from the radius rod lug. How did you clamp it to keep it from distorting the torque tube? John
That's what was done with mine. My last drive shaft broke because it was cut and rewelded with a sleeve. Maybe alignment was a secondary cause. "hollow '32 style shaft." - If that's the case maybe I could remove it.
I'm sure there's a simpler way to do it, like welding it while it is bolted in the car as suggested above. I had the good fortune of having a friend with a platen table (super flat steel table with a gridwork of holes in it to facilitate clamping fixtures) and he made it work. I had an extra banjo center section which he secured to the table and bolted the torque tube to and then we came up with something on the front end, can't remember what, to locate that end and checked it all for straightness and accuracy then welded it and let it cool in the fixture. He's super meticulous and it was all him, I just watched and handed him tools. Good luck, I'm sure you'll figure something out.
I went through this on my '33 when it was still closed drive. If you cut the tube with a 4" pipe cutter it makes a really nice straight cut. This is crucial for later of the rejoining. The as you shorten the shaft either by sleeving a solid one or making the '32-'34 style shorter make sure this is lined up first. Easiest to buy a new tube and turn the old ends to fit as a press fit. This'll keep it straight when welding. TIG is the best but a MIG will work just as well. Once you have the shaft straight and the right length then move onto the Torque Tube. You will need three lengths of 3/4x3/4 angle about 12-16", big hose clamps, and a straight edge. This is the ghetto way if you don't have a bunch of fancy equipment. I clearly can live in a ghetto just fine so no suprise here. Make sure the Torque tube is bare metal and clean as a whistle, don't grind onthe tube use a scotchbright or wire brush to clean it up. Now remember the pipe cutter mentioned above? If you didn't use one then do your darndest with a grinder to square up the ends and chamfer 45' halfway through the thickness of the tube for a nice strong weld. Place the angle at 120' intervals and hose clamp them on with the tubes joined tightly halfway on the angles. Take your straightedge and check for alignment of the tube. When it's perfect weld the seam up in even 120' spots overlapping the previous weld a little to ensure a tight seal and joint. Remove the angles when you get good solid points between the angles and continue welding in opposing spots. Install your new straight tube and driveshaft and go cruising. all the best, Tim
Thanks for the input, But I really don't think its the mount. both sides were trued up in a lathe and then tig welded. The problem seems to be the geometry between the front snout bearing and the center bearing causes the center drive shaft to go "up" at the point it meets the banjo center.
There are two very critical areas to check when shortening the drive shaft. Both revolve around the axis of rotation point. It is of utmost importance that the driveshaft and the torque tube both be constructed on this central axis. If either is off it will produce a misalignment that will cause a vibration or the drive line to fail. If you are installing the torque tube to the banjo it should easily align with the pinion snout. If you have to apply any tension to ensure that it is aligned, it is placing a bind on something meaning the axis are not the same. I feel that in this case it may have something to do with the center bearing. In shorter driveline applications the accuracy is much more important. If you have any variation to the central axis it will create a missalignment issue. The drive line axis is created by the fixed point at the pinion and the center line of the upper torque tube bearing.If you install a mid bearing you now have 3 points that must align, since you install torque tube front to rear the upper bearing aligns with the central bearing and devates the tube postion when you join it at the banjo. Your options are recheck the central axis of the drive shaft and torque tubes to insure that they are not bowed or welded off axis or remove the center bearing because it is not centered in the tube. If you spin the torque tube as you have it pictured to the 6 different clocking points and the tube flange remains in the same relation to banjo flange then I would be looking at the drive shaft. If you spin the drive shaft and the flange stays the same then the torque tube. Because the spacing of the flange seems uniform with the banjo flange I first would remove the center bearing and see if it cures the alignment.
There are several posts here referring to bent torque tubes caused by welding on the radius rod lug. This is a very easy fix. I just did mine recently. I knew the welding would distort the tube, and it did. Once it was done, I turned over the tube and laid down the exact same amount of weld, in the exact same pattern, to the opposite side of the tube, ie: 180 degrees. I then put it all together, stood the entire rear so the torque tube is facing up to the sky, and slipped the top bearing over the drive shaft. It did not drop into place, so I ran one more line of weld on the dummy weld area and bingo! The bearing just dropped into place, proving that it was dead straight. I then ground off the dummy welds (they're not needed, it's only the heat that's needed) and rechecked the bearing would slide on with no binding or force needed. Hope this helps. BTW: I dont think the center bearing needs to be used in a shortened setup. More trouble than it's worth. BTW again: I shortened my drive shaft by cutting the required amount off the coupler end and turned the new end down so the coupler would slide onto the shaft as a firm fit. I then welded the coupler on while checking for straightness. It works just fine, runs at 60mph with no vibration and no issues.
Is a stock 32 ford torque tube a direct replacement? will the later(40's) driveshaft and 48" radius rods work with it?
In the "olden" days when I learned to stick weld with a Forney Arc Welder, we had a slag hammer to chip off the flux when the weld p*** was completed. One side effect of this operation was peening the weld to stretch it and minimize the pull/distortion as the weld cooled. I would suggest that you heat your weld with a torch and peen it to relieve the shrink that is pulling your torque tube out of alignment. When I shortened a '40 rear to fit my '32, I cut the torque tube close to the rear flange. Then I reshaped the radius arms to fit the lug in its position. The center bearing is not needed in the shorter tube. I cut the solid drive shaft to the new length and cut a new spline on the end. I didn't want to weld on solid shaft because of its "tool steel" properties. I hope this helps. I have heard that some shops that work on large trucks are good at straightening axel housings and drive shafts. They may be able to fix it.
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