Hmmm. What if I don’t jack anything up and just work with it that way.
Still going to put a jack stand under the torque tube.
Wouldn’t that be a neutral load on the torque tube?
Doug
That would work, but a jack might be better so you can move the torque tube up or down as needed to disconnect the u-joint. But the load on the torque tube won't be neutral because of the leverage from the pivot position (see below.)
What makes this more dangerous or different from a normal driveshaft? Is the rope drive torqued or under tension? Does it drop with a force greater than its weight?
The pivot point of the rear axle is forward of the centerline of the axle by a few inches. What makes it drop with more force than it's weight is the leverage of the weight on the rear wheels translating to a downward force at the torque tube, But like a teeter-totter that's short on one end, the long end of the torque tube needs less force to move the pivot. But if unrestrained, it would move faster than the wheels would rise relative to the spring mount point.
Also the rubber bushings are supposed to be neutralized (loosened and then tightened) with the truck's weight on the wheels and the u-joint connected. When the truck is jacked up by the frame, the wheels are unloaded, but the "spring" in the rubber pivot bushings is wound up from the axle dropping. That turns the pivot spring tension into a downward force on the front of the torque tube. If the torque tube is not supported, it can snap downward when the u-joint is disconnected. But it likely won't go all the way to the ground, and will probably rebound back up partway.
