I had the cut the bolts holding my driveshaft to the front output flange of the transfer case last night so I could replace a u-joint. Those suckers were in there hard. I'd almost say that u-joint has never been replaced. What is the size of the nut holding that flange in place? It's bigger than an inch, which is the biggest socket I've got. Looks close to 1 1/2" maybe. My L230 rebuild manual doesn't say.
Also, if I pull that will I be draining transfer case oil all over my face as I suspect? If so, I think I'll cut the rest of the bolts out and install the new ones backwards to avoid that. It's a shitty way to mount them anyways as you're forced to remove that flange to replace the bolts in their current config.
Do you think the u-joint cups in my pic could have been the source of my drivetrain rattle?
Normally I'll replace a u-joint with the driveshaft on the truck. In this case I had to pull it because those cups had expanded and wedged themselves in the yokes. I needed to bang on them like a crack monkey to get them out.