1995 325 Convertible- standard trans noise

[wakman]

The 1995 325c with std transmission has apprx 85,000miles
no winter driving
Have a rumble type noise that you can feel thru the shifter.
Even if in neutral and just rolling in no gear, can feel and hear the noise.
BMW dealer says its a transmission bearing and i should install a new transmission.
Any one have this same noise or problem??
Is this common on the 3 series std transmissions??
Where is best place to source a new/rebuilt transmission??
Or do i try to fit the bearing inside the transmission??