Truck Arms

You'll need to modify the spring seats a little bit to get them on the 9" rear since the axle tubes are different diameters but that's not a big deal. You may also want to use the factory panhard bar since it's already the correct length. I don't think the factory bar is level to the ground but it's also not a straight bar so that just may be the way it was enginereed (that or there was a packaging problem or no one put much thought into it).

I would think that if you duplicated what GM did on their trucks, you wouldn't have a problem with broken parts.

Matt

I think you have a well thought out plan for your project.  I offer this up for anyone who would like to replace the torque tube transmission without replacing the rear suspension.

Build a mount for the torque tube independent of the transmission, or modify the extension housing to accept the toque tube flange.  The toque tube and drive shaft length can be adjusted to the location of the output of the replacement transmission.  The torque tube is 'dry'.

Modifying the Torque tube is a possibility.

Johnny's hit the problematic nail on the head! There IS a slip joint though. The U-joint on V-8 models just slips in the transmission output shaft, on six cylinders it slips on the trans AND the solid driveshaft. The problem is it slips on, but is designed to stay in one place. It's not as long as an open drive slip joint.

Theoretically the flange on the 63-66 torque tube could be bolted to a metal plate that is then fastened to a crossmember. That plate has to be able to take the axle pushing and pulling (when braking) on it though. The 63-66 cars have arms attached to the crossmember for this and the crossmember is rubber mounted. Those cars go through engine and trans mounts more than others since a lot more road stress is put through them. It's not like the mounts need to be replaced often, but by 100K miles they are pretty worn.  It's just not very feasible to do this. You could weld a flange on the back of a trans -- one welding shop was confident they could cut and mate a BW and an AMC 904 tailshaft housing, but I didn't like the idea. It should work though.

Mark, Hot Rods to Hell sells a G-body GM kit that looks like it would be easy to mod for Ramblers (http://www.hotrodstohell.net/truckarm/truckarm_gbody/truckarm_gbody.htm). The springs sit on the axle just like our cars. A little modding of the crossmember should be about all it takes. If you want to build your own they sell the arms separately (http://www.hotrodstohell.net/catalog/catalog.htm#CC). That might be your best bet.

I think a square tubing arm would be a good choice. The trick is the tubing can't be(1/16" sidewalls) should be good, 1.5-2" wide, 3-4" tall. The tall cross section will prevent bending, the gauge is light enough and the tubes narrow enough to allow flex. 10-11 gauge would be to heavy to twist much, but something like 14 gauge might be better if you're going to be shocking the rear axle a lot. It just won't twist as easy. Round tubing won't work well at all since it can't twist like rectangular tubing or I beams would.  The arms need to be long so they won't twist much. Too much twist and they'll stay twisted. The longer the better! The angle prevents too much twisting also.

If/when I get another 63-66 big car body I want to build a truck arm suspension. Would love to make a kit for these cars! I know, just tow that Ambo down here next summer, pay for the materials only, and I'll mock up and test a kit on your car!   It will be next summer before I have the shop ready for a big project.

Of course you have to change the rear axle as well. The AMC 20 for the TT cars doesn't lend itself to open conversion. There is a seal holder that can be bolted on without the tube, but I'm not sure the yoke from an open drive car will match the splines and size of the pinion shaft, and the pinion shaft isn't drilled for a bolt. You could always drill the yoke for a big set screw or two if it's just a cruiser, but that's if the yoke will even fit. Then you have to find a yoke too. 

Edited by farna - Aug/01/2007 at 1:25pm

JohnnyRebel wrote:    I like the way billd uses to terms fun project, and great challange in the same sentance. This man is obviously an incurable optimist.     I have thought about what Peter suggested. It seems to me that the problem lies in the adjusting of the tube and shaft lengths. without a slip ( My factory manual shows there isn't one ) joint in the shaft you would have to get the length exactly correct. The tube could also be cut and rewelded to a different length, but again same problem. I suppose you could fab motor mounts that would give a small range of adjustment fore and aft, but would they not come loose?

Attach a flange to the replacement transmission (weld or bolt), attach the flange the same distance relative to the end of the output shaft end.

Measure the length of both transmissions, the difference is the amount to shorten or lengthen both the drive shaft and the torque tube.

The turbo 400 yoke may not be available to fit the universal joint on the torque tube drive shaft, but the proper yoke can be welded to the drive shaft.

I am not suggesting anyone DO this, I am just  pointing out a way to keep the torque tube(I no longer hate the toque tube).