Now for the DIY rear coilover setup. I finally finished my rear coilover mounts for the Viking coilovers I ordered.
Here are the details for anyone who may be interested:
I wanted to use an adjustable lower mount as a frame "Z" may be in my future (I will not C-notch the frame, I measured and I would get at most .5-1" of additional travel before hitting the bed- so it isn't worth the hassle). I also wanted to be able to adjust my drop without using only the coilover spring preload.
I looked into what I thought may work and settled on a design that would mount the lower mount in double shear, rather than single shear, and have adjustability up or down if I ever need to make a change (or I get it wrong the first time!). This is my first C10 rodeo...
For the design, I would use .250 wall 4" box section to box the trailing arm, and weld on a universal axle tube bracket for the lower coilover mounts:
Like this
The tricky part was that there are a lot of angles involved in getting the mount, trailing arm, and coilover to not bind and not have interference while maximizing shock travel (I managed 10" of axle travel). I spent a lot of time measuring at all of the possible ride heights and throughout full articulation, checking for tire clearance, eyeballing shock angles, test fitting, and starting over. It all ended up working really well, but there are some compound angles and tight clearances required to make it all work. The c-channel is level, the shock mount has a 30* layback and a 5* tilt. The first mount took a day of fiddling, the second took an afternoon including finish welding both parts. .250 wall steel is no joke, it takes a lot of time to cut and shape. I was very thankful for my little bandsaw to make the major cuts. For welding, I used a MIG and I did a root pass and a finish pass on my welds to give the bracket as much strength as possible.
Fun fact, a lot of folks will tell you that the trailing arm setup doesn't twist due to the solid axle and the panhard bar. They use this to justify why you don't need any flex in your trailing arm bushings. I measured the rotation of each trailing arm at +/- 4* before binding. This doesn't sound like a lot, but it is significant.
I have tacked the mounts into place, but it is late and I want to do it right, which means cutting the tacks off to use some weld-through primer under the mounts before finish welding. I'll get the final pictures of the welded mounts tomorrow. The ones here are just the root pass.