Re: AMC 20 Truss
I think your headed in the right direction....I am also planning a similar mod...but based on my last experience on some tough trails (translation, dents and scrapes on my axle) I am approaching it from a different view.
First...lets look at where the loads are. The greatest load is twisting created when under load. This action is seen as the diff trying to point up towards the floor...and is really seen on SOA as spring wrap. As long as the spring perches and tubes are welded, its not going anywhere.
The next worse force is when you park the pumpkin on a rock...now the weight of the jeep is sitting out there on those weak tubes....i.e., bent tubes.
One of the guys on our last outing had a truss that kept getting hung up on rocks....Based on that and what happend to mine, I plan on keeping the bottom portion as clean as possible and adding a skid plate to the pumpkin...the plate will need to go the back high enough so that the next time I'm sliding backwards and my gas tank slides off that big rock, the rock doesn't put its imprent on the cover. (yes...it trashed my gas tank shield...but don't worry, I just installed a new one that I made out of 10 gauge plate steel, it makes great place to jack the jeep up now). I want to weld a truss to the top portion of the axle....I'm actually thinking about making 2 triangular shaped pieces of plate steel and welding them at a 45 deg angle to the tubes...kinda like a V as viewed from the tube end. This will give the most ground clearance possible. My only other problem is how to attach the skid plate. Can't weld it because it has to be removeabe in order to remove the cover plate on the diff. While I am at it I am also going to reversed U-bolts and a different shock mount (yea, they got torn up too).
Maybe we should get someone to work this up on MCad and run a FEA on it. Then we can see where the real stress is.
Any other ideas?