motor grommet/bushing
 

2002 Yamaha G19 with D&D motor and controller. Was having increasingly loud whining noise on acceleration and deceleration, and found that the input shaft bearing (not the sealed one) is worn badly. New input shaft kit on order and was wondering if I should go ahead and install the rubber grommet/bushing between the input shaft and motor while I have the motor off, even if that wasn't the cause of the noise. It didn't have one when I took the motor off.

Re: motor grommet/bushing
 

Update: Replaced the input shaft and bearings with the new rubber bushing as well. Differential noise went away. I had already ordered the outer sealed axle bearings and inner axle bearings just in case, so I installed them once they delivered. Everything is running smoothly now.

Re: motor grommet/bushing
 

I hope this fixes your noise issue. I had the same issue and found that replacing the grommet stopped the noise for a few weeks, however, it came back. I haven't tried the "penny trick" but I may give it a try. I have also noticed there is a tiny bit of "play" when switching from forward to reverse or vice-versa. Concerned about that.