Getting started on the transfer case bypass today after getting the metal yesterday. 5 inches of 6 inch outer diameter .250 wall seamless pipe for the extension and then .375" plate for the front and back flanges.
12"x12" piece for the back flange even though I only need a 6" diameter circle because that's the smallest piece I was allowed to buy. So I took the gasket I bought a while back and scribed the inside and outside edges of it, the drilled hole is a starting place for the plasma cutter to knock the inside circle out.
There is the back flange rough cut with a little bit of cleanup on the edges.
Took my piece of pipe back to the lathe, dial indicator to make sure it's square enough to start machining material off it. Was able to get it down to .008" of wobble and felt like that was more than straight enough to start cutting.
My piece of pipe was actually still not quite large enough on the inside to clear the bolts from the output housing so I opened the pipe up a bit on the inside. I also machined the end of the pipe as true as the situation allowed so that I could weld the back side flange as a cap and have it straight enough to no affect the driveline angle much.
Inside of the pipe machined out enough that the output housing bolts can live happily inside.
Had tacked the flange to the pipe and started truing everything up. Went ahead and checked the face, everything seemed pretty straight still. I had pulled some material off the opening at this point but it still needed a decent bit of work.
After getting the edges cut down to something closer to flush I finish welded the cap onto the pipe. I haven't done anything with the TIG in months so I was plenty happy with this. After getting it welded on and giving it a good long cool down period it went back onto the lathe. Surprisingly it barely warped and getting the face back flat was a dawdle. It took a bit but I eventually got the inside cut enough that the output housing is a nice tight slip fit. There shouldn't be any need for that kind of precision on this piece, it's not like there will be any real side loading or twist force on the housing.
The piece is done now, got the mounting holes drilled and tapped and everything. It'll need to be cut to length eventually but I need the front flange made first.
And there is the extent of my progress on the front flange. I've got another larger piece of .375" steel and that's the gasket that goes between the transfer case and transmission. Got one hole partially drilled and that's it. Getting the other piece done took five hours of the Sunday and I was got doing actual for pay work part of Saturday and I figured I'd be in trouble with the missus if I stayed out any longer.