Were the heads of the bolts hitting the diff on accel or decel? If accel, then your gears are backwards. The side gears should move out under accel pushing the CV's away from the housing.
Jon, neither/both. I was getting static interference with the diff case while coasting. Was unable to spin the wheel by hand, because the bolt heads were contacting the side of the diff in their static position until I pried the flange out a bit...but I doubt that the circlip is properly engaged now.
That stub needs to be clipped in. If it's not it could slide out a bit and strip the splines off. Saw a pic of that from an EVO just recently.
What if that stub was never engaged even before I started this project? Maybe they're already stripped and that's why I have the slop? Why would I be able to feel slop on driver's side but not the passenger side? I know you said this not a good test, so you're saying it's normal to be able to feel the slop I'm describing on one side but not the other...? I guess I'm just missing something about how these gears engage, sorry.
Is there a stub axle maybe from a different car with the same (or slightly different but worn) spline count that would slip into the driver's side of an R200 but is slightly too short (groove cut 1/8" too close to the flange) to clip in without interfering with the case??
I really don't think this is an issue with the OBX unit itself (guess I should've started a new thread?), because it feels like I'm discovering a pre-existing issue that I didn't know was a problem. The only way the OBX could be at fault is if I got the preload way wrong, and therefore the washer stack isn't spreading the sun gears apart enough to locate the stub axles correctly...