My Bosch Universal mixer, MUM 66630, has a musty smell when I remove the lid to use the mixer.

SOURCE: Can't get the drive coupling off my Bosch Universal to replace it

I have had my Bosch Universal Mixer with the Blender and Food Processor Attachments since 2005, and I've loved it since the day I got it... that is, until the blender broke while my son was crushing ice to make slushies...

I figured out the "drive coupler" was stripped and needed replacing, but I couldn't figure out how to take apart the "blade assembly" which includes the "drive coupler" part...

My retailer, Pleasant Hill Grain, sent me the following email:

"I am not aware of any printed instructions for removing the old coupling and
replacing with the new. We recommend holding on to the blades with 1 hand and a
towel and using a needle nose pliers to unscrew the old coupling. You would put
the new coupling on in the same manner.
If these instructions do not work, I would suggest contacting the Service
Dept at Kitchen Resources in Utah. Their phone is 800-692-6724."

I still couldn't figure out how to take apart the blade assembly, so I did end up calling the distributor, Kitchen Resources...

Dave, the tech @ Kitchen Resources, answered my call on the first ring...

Once I explained my problem, he started giving me the same instructions Pleasant Hill Grain gave
me... I explained to him that holding the blades tightly wasn't working for me.

As it turned out, holding the blades did not secure the drive shaft because
the drive shaft was broken off INSIDE the blade assembly - which is why I could
not unscrew the old drive coupling part.

Dave's next question revealed the true issue at hand... my Blender Attachment has the blade assembly made of plastic - they switched to plastic
in 2005 because the metal assembly turned black in dishwashers.

Bosch just recently went back to using metal for this part - apparently the
plastic blade assembly didn't hold up.

Kitchen Resources - the U.S. Bosch Distributor - is sending me a new blade
assembly - no charge, he said it's covered under warranty. Woo Hoo!

Best of all, I hadn't yet purchased the replacement drive coupling part, because
I wanted to know how to go about replacing the part before ordering a new part.

With shipping this part would have been a $50+ repair - you have to love
customer service of that caliber!

[Aside: You really don't need to ever put this part in the dishwasher - wash
the inside with by putting hot water and perhaps a little dish detergent inside
the blender and turning it on - rinse the outside under the sink... no
dishwasher needed! ]