I am sure that some of you have heard or read about this: I have an 09 with 7900 miles on it when I discovered that 6th gear was griding while speed shifting above 5k and 5th above 6k. The dealership is in the process of changing out the synchronizer for 5th and 6th. the dealership hadn't heard of a problem but the tech desk advised of a new part number for the sync. Glad they gave me a loaner for a couple days.

 

Looks like your dealership is offering you a good service!
These issues were already debated though and apparently mazda changed the synchros

 

been there done that. at about 3000 to 6000. have 30000 now without any problems

 

Happened to me too. 5th-6th and then later 3rd-4th.

All under 5,000 miles.

No problems since they put the "upgraded synchros" in there.

 

Same here, upgraded synchros and problem is gone.... only 7900 miles now though...