Hi All
Bob is correct, with no load the shocks don't have much if any effect on the ride. On my HUP driving with out shocks is noticeable. I've noticed the difference even more when one of links breaks. With the HUP one disconnected is far more noticeable than pair.
On the 3 tons the shocks don't do much on cab chassis or even on C60L with cargo body because the springs are so stiff. I suspect that the once the GVW gets up around 10,000lbs on the 3 tons that the shocks start to work.
There used to be a nice straight uniform bump across are road where a culvert crossed under road. When I'd hit that driving the HUP you knew if a link had let go. Being a late version mine has the metal ball type and over the years all four have failed generally at the lower weld. Each has been rewelded. Pictures of link and break point
http://canadianmilitarypattern.com/HUPdetailphotos.html
Alex think I'll follow your idea on having new shafts made, though Bob's approach might be quicker. The shocks for my C60L are still sitting on the shelf to be installed.
Cheers Phil