My scooter is making loud clicking sounds as though something has come loose & hitting something in the rear wheels as it goes around. The repair tech rotated the rear tires last week & this helped some, but it continues to make this sound & is getting more frequent again. Any ideas as to what this is & how to fix it?

Its quite common for Pride scooters to be assembled using little or no grease on the rear axle. If the noise is like a stone stuck in the tyre, its probably a 'Dry Axle' as mentioned above. Try just removing the rear wheel(s) and greasing the axle. This normally cures the problem. When removing the wheel, be careful not to lose the hub key which slots into the axle and wheel to stop the wheel spinning freely on the axle. Hope this helps.

I had the same problem and posted it here on FixYa, but now that I found a solution, I can't find my way back to where I asked. Anyhow, this is what fixed it for me....

"This can be caused by two things usually. One cause is the bolt holding wheel to the axle is a little loose so check to make sure it is very tight on the axle. The second click comes from flat-free tires. The tires have an adhesive applied at the factory and if you hit a bump, or if there's not enough to hold the tire tight to the rim, the tire will make a grinding click noise when it rolls and passes over this area. Pneumatic tires properly inflated don't make this noise since the air pressure keeps the tire fixed to the rim at the bead; flat free tires lack this pressure. Simply lubricate the area around the tire where it meets the rim on inside and outside, and drive it...noise should dissipate."
http://www.fixya.com/support/t2847914-click_clunk_when_moving_from_right_rear

Mine was the tire/rim problem. Here's what I did:
1. Separate rear and front sections of the scooter
2. Stood the back up so it was setting on the outside of the right wheel, the left wheel up in the air, horizontal.
3. Sprayed a bead of silicone lubricant around the rim on the outside of the left wheel and the inside of the right wheel.
4. Sprayed around the axle at the wheel, and at the bearing (both wheels)
5. Let the back end sit in that position about 5 minutes.
6. Turned the back end over so the right wheel was up and it was resting on the left wheel. Repeated 3 - 6 until each wheel had been sprayed on the inside and outside three times.
7. On the third repetition I used my thumb to press the rubber around the rim, inside and outside on both wheels.
8. Repeated 3 & 4.
9. At this point the rubber on the wheels was feeling softer and would compress and release.
10. Put the front end and back end together, and drove in silence.

Hope the good tip I got might help someone else!