RE: TRF801X Build Thread
The manual tells you to attach the rear and bulk heads here. I would recommend not completely tighten the screws, and leave a little room at this point. (Kind of hard to see in the photos, but there is maybe one turn left in the screws.)
People have reported the stock screws tend to get loose in the bulkhead. I find it ok until you take the bulkhead off a few times. Recommended fix is longer screws, or a piece of plastic in the screw hole before tightening.
I also used the joint grease here as a test.