I have a well maintained 240 Wagon with 5 Speed that has started making a rapid ticking sound from the rear end on deceleration. I checked around under there and found that the pinion flange has about a 16th of an inch of side to side movement and knock. The diff was still full of clean lubricant, and surprisingly the seal seemed to not be leaking. The diff sounds quiet on the highway, but the driveshaft does feel like it might be going off balance. The u joints seem fine and I replaced the center bearing, rubber housing, and rubber coupling last y

Is it possible, that I could get away with simply re-adjusting the pinion bearing pre-load (and maybe replacing the seal while in there)? Based on the serial number, it appears to be a non-crush sleeve model. I am hesitant to start a full diff rebuild, and any local rear axles that I might find are likely to be very rusted compared to mine. Suggestions?