Thinking

At this juncture, considering I already have a completely separate sub assembly, how cool would it be to have sliding tandems like a big truck trailer, sure it may be an odd case to actually need to move the tandems forward to accommodate a load of some sort but the simplicity of it at this point is hard to resist. Unfortunately, I do not own a magnetic drill (wish I did) but I may be able to get hold of one and bore the 1" holes in the tubing for pins. I think I will buy some 2" X 3" .25 wall angle for tracks and weld to mainframe. If I'm thinking correctly, I can only have half the space inside the subframe for movement forward or back. So! I will have sliding tandems able to move forward 33 inches...

Tires mounted

Positioning subframe with axles

I jacked up the subframe as a unit with axles and used two hydraulic floor jacks to position under mainframe.

Mounting axles

I stood the subframe up (heavy) and lined up the first axle spring eyes and slipped bolts in them. I lined up the second axle and lowered the subframe onto springs, installed bolts.

Deciding how to mount axles

I have a 6 inch boxed main frame and the bed frame I anticipate building will lay directly on top of the main frame and be welded, therefore, I do not have enough clearance for the tires without some form of spacing. I can see I need a minimum of 4 more inches. I went to the steel company and picked up two pieces of 2" X 5" rectangle tubing .25 wall. 72 inches long each. (I asked the fella if he could cut them to 72 inches precisely, I got them at 71 15/16 each, heh, not too bad)

During the drive I decided the best thing to do was to weld spring hangers and equalizers to tubing first, progressively that turned into welding a completely separate subframe, cut my channel for crossmembers, weld together subframe.

Axles

Okay folks, I managed to get a day to do my own stuff. Here is an image of the axles 7,000 lb each, 8 lug on 6.5 pattern