Ford Tempo ATX--differential side bearing replacement question

Hello---I have for the past couple of days noticed a "vibration" or "noise" from the front end area of my 1990 Tempo with ATX. It sounds very much like bearing noise. It becomes noticeable at about 20 mph and increases with speed.

At first I thought it might be one of the front wheel bearings, but they were replaced 18 months ago (along with the halfshafts). I jacked up the front end of the car and shook the axle shafts. The front wheel bearings and CV joints seem tight. However I noticed on the right halfshaft inboard joint, a noticeable "jiggle" or "looseness" where it enters the transmission. I don't get this on the left halfshaft.

I am suspecting that one of the differential side bearings is getting bad. I have the Ford repair manual, and it doesn't appear to be too hard to remove the differential from the transmission (remove the halfshafts, remove the oil pan and filter, slightly raise the tranny, unbolt the left-hand bearing retainer, and drop the differential).

However, the manual says that differential side clearance needs to be checked after bearing replacement. The manual shows a procedure involving special Ford spacers, etc to do this.

My question is this: how important is it to check the differential side clearance if I replace the bearings? Is it likely to need checking and shim adjustment after new bearings? I'm pretty handy when it comes to fixing cars (I replaced the halfshafts and front bearings myself on this car). So I'm not afraid to tackle the relatively simple job of removing the differential. Thanks for any advice!