Hear a grinding noise around the differential area when accelerating while going straight or right. Noise is less when not accelerating and at speeds at or greater than 50MPH. Almost no noise at the higher speed even when turning right. No noise during the following conditions, when turning left, in neutral, clutch pushed in, when front end of car jacked up and shifting through all gears and turning right/left at different speeds.. Car is Geo metro 3 cylinder, 5 speed, 221,000 miles. No noise or problems when shifting gears (runs like new). Noise began after replacing drive axles and transmission fluid (used Synchromesh manual transmission fluid recommended in service manual), Replaced drive axles, right wheel bearing, tie rod ends, clutch, flywheel, pilot bearing, throwback release bearing, right and left drive axle seals. My car has 221000 miles. My car has a 5 speed manual transmission.
After reviewing your case I have concluded the left wheel bearing should have been replaced as well. In most cases when you can make the noise change by turning or swerving then a hub bearing is worn. I see you have replaced the right wheel bearing already. I would look to the left wheel bearing to be in need of replacement.