I have over one inch of rotational play in the driveshaft of my 1997 Subaru Legacy GT (215k miles). Link to video of actual vehicle and symptom below.

 

Vehicle makes clicking sound when NOT under load (accel & braking). Lots of regular clicking that increases in frequency with speed while coasting. R&R'd front axles, rear's look good. Driveshaft has zero fore/aft play but over 1 inch rotational play. U-joints feel solid and are not the source of play. Sound seems to be coming from inside rear differential. Checking/changing diff oils now, although I feel this is some larger mechanical issue. Thoughts? Thanks in advance

 

Rotational play is normal. The clicking could be due to worn side gears in the differential. Check fluid for sparklies.

Is the car auto or manual?

Just changed fluid, looks normal. Some very fine accumulation on the magnet, but oil looked good and was free of any metallic flakes/chunks. Car is an automatic.

yep - rotational play sounds normal.

 

that's a pretty good description - can you add any more mechanical/technical details, it's hard to go on words.

 

symptoms didn't change at all with any of that other work?

Put a fuse in the FWD fuse holder on the passenger strut tower and see if the noise changes.

 

Does it change if you turn tightly in one direction or the other?

It only makes the noise when coasting?

Symptoms are exactly the same when in FWD. I guess we can eliminate the rear end?

 

Some folks on another forum suggest wheel bearings. "he reason the bearing does not make noise when braking; is because the rotor is attached to the cv axle and inner bearing race. So when the brake caliper sqeezes the rotor it straightens it up. When the rotor, and inner bearing race are straightened up there is no more noise because the bearing inner is not sitting crooked against the bearing outter."

I would also be inclined to think wheel bearing, but I would expect there to be noticable play in the bearing if it were that far gone. Did you check the bearings for play before?

 

It doesn't necessarily rule out the rear, because as you said it only makes noise when coasting.

 

Does it happen at slow enough speeds that someone could walk next to the car and listen from outside?