I’m at the point in the build where I’m getting ready to lock the engine/transmission down and shorten the torque tube & driveshaft. ‘31 body & chassis, ‘39 trans & ‘39 banjo. Millworks AV8 rear spring and bolt on spring mounts. With the spring installed and u-bolts tight, the pinion angle is down like 7 degrees… I loosened the u bolts and jacked the pinion up and re tightened the u bolts and now it’s still down about 1 degree, but I didn’t want to keep jacking up the pinion… this is one of those things where I don’t know if I’m over thinking & analyzing, or if I’m missing the boat completely. The spring hangers are labeled left and right and on correctly…. Usually the tube is on the rear and I connect it to the trans first and then raise the rear into the crossmember so I’ve never had to address this issue. Thanks!
Put a bar in the coupler and jack the shit out of it. I do it for every torque tube I measure to shorten
You are working against the spring, twisting it. You can either bolt the torque tube on and bolt it all up or A- modify to shackle brackets on the rear to angle the housing up or B- cut and weld the rear spring crossmember parallel to the angle of the rear when at ride height so that the spring will not be I. A bind (twist) when compressing in the arc of travel dictated by the angle the spring shackle brackets. If you match the angles up at ride height so there is no twist on the spring it will ride much smoother. The chive is yours. But if you just jam the spring in the crossmember twisted, and you are using shackle bushing that are plastic like from speed way or Pete and Jake’s, the won’t last long. Stock type with the link and bolt will work fine.
I was thinking of messing with the spring mounts…. I think they sell degreed ones for quick change applications that point the rear up towards the transmission. I am using stock style bushings in the rear, by the way. Those plastic ones are junk.
You need to cut and install the torque tube, and deal with the spring/hangers later, that dictates the pinion angle.
On my RPU with a quick change I had to swap the arms to left to right/right to left to raise the pinion angle
Get your torque tube bolted up. The TT controls the position of the pinion. Additionally you want the weight on the spring. So ditch those jack stands and get all four wheels on the ground. The lower and deeper the rear goes into the body also effects your pinion angle. Thankfully closed drive set ups are not very pinion angle dependent. An open drive conversion is a whole other can of worms.