My guess is a motor getting ready to spin out, or something inside the RDM.
I'd have it diagnosed before too long. If it does happen to be the motor and it spins on you, not only will be stranded, it could also damage the RDM beyond use as well, making the repair even more costly.
I'd have it diagnosed before too long. If it does happen to be the motor and it spins on you, not only will be stranded, it could also damage the RDM beyond use as well, making the repair even more costly.