Looking for a little help from the group. The car now has about 85000 miles and is well maintained.

As of late my car has developed a buzz from the shifter in 5th and 6th gear at speed. The greater the speed, the more noticable the problem. Say 6th gear at 85 mph it is actually audible and easy to feel if you rest your hand on the shifter. At say 60 the problem is not noticable unless resting your hand on the shifter with just a little pressure towards the passenger, and even then is not audible.

Fluid was changed about 4 months ago with Mobile1 ATF which had little to no impact on shifter feel. Maybe I should try another fluid? Could it be the center bearing on the drive shaft, or the whole drive shaft needs replacing?

Any ideas are appreciated.

Thanks, Greg