Bear with me while I rewind to last Wednesday (the day before Thanksgiving). I get a call while I'm at work from Nick at Sosebee Offroad to run by the shop. I was expecting to grab my trailer as soon as I got off at 5pm and pick the rig up ready to ride. He's only a few minutes away so I ran over there and we had problems. While trying to bolt the UBs onto the knuckles, everything got into a bind. Basically you couldn't steer more than a couple degrees and nothing would spin. It was around 4pm so I frantically called up Kraig since I had his cell number and he answered the phone. I told him what was going on and he said send him some pictures and he'd have someone from tech call me back. I got a call back a few minutes later from a couple really nice tech guys at RCV. Can't say I was very pleasant to talk to but they we helpful.
Long story short, the outer stubs that RCV is selling for these knuckles/UB combo DO NOT WORK. The RCV shafts are designed for 450/550 knuckles whereas Reid clearly states their castings are based off the 250/350 knuckles. Really the only difference here is a 1/2" bigger spread between the two knuckles however when you go to bolt everything up, the knuckle binds like hell because the stub can't go deep enough into the UB, it bottoms out and jams the CV back into the inner C which then binds everything. Apparently somewhere along the development cycle this was lost in translation between the two companies and RCV is now working to come out with a new stub for this application. Well at this point I hung up, told Nick to forget it there was no way I'd be able to ride Thanksgiving weekend, he gave me a jar of moonshine and I headed to the bar. After a few beers and I started to relax I had an idea. I had the phone number of the guy that was the first to put an axle like this together. He's an Ultra4 guy at in California. I rang him up and he answered. I started in on the issue I was having and he cut me off almost immediately and said "bore the backside of the unit bearing an additional 1/2 and call it good." Apparently he had gone through the same exact problems and that was his fix. He said it worked so well he never called RCV back to discuss the new shaft in development. At that point I threw out an SOS text to my machinist buddy to see if he felt like doing some machine work on Thanksgiving and luckily he said no problem. Once I got the machine work done, the rest of the axle literally went together like butter.
First two pictures are of the stub bottoming out in the UB. Third is machine work in process and fourth is the backside of the UB after the additional 1/2" of splines were taken out.