I replaced my alpha with a Stenrdrive Engineering unit last year. It's always been noisier than the original, which I attributed to new gears. Last night it was quite loud; today it definitely sounded like something is wrong. The noise appeared to be coming from the upper. I drained the drive oil and it was pure - no metal particles. I pulled the top cover and inspected the gears and upper bearing, which appeared to be fine.
I pulled the drive and found one of the u-joint grease fittings had come off and was sitting in the bellows. The threads looked beat up. Could that have been hit by the u-joint to cause all the noise? The gimbal bearing seems fine, but I don't have much experience in this area. There is some wobble when I insert the alignment tool and wiggle it. With a metal ruler held flat on the bell housing face, and the end of the ruler up near the alignment tool, I see about 1/32" movement. Is that normal? I adjusted alignment and it took about three full turns of each nut to get the spline marks looking even on a greased tool - is that a lot? Again, I don't have a lot of experience.
The engine ran with no unusual noise with the drive off.
I'm strongly inclined to replace the gimbal bearing as it is probably 12 years old. Engine has about 600 hours.
Looking for other diagnostic or fix suggestions.