I am a new (to me) owner of a vintage Bosch UM3 from eBay. When I got it all set up and tested it with the dough hook in the empty bowl the bowl itself seems to be wobbling a lot. I have noticed SOME wobble in a couple of YouTube videos, but I would like to know if this is too much.
Note that the bowl IS locking in place - while it wobbles I do have to turn it clockwise to get it off the base.
Here's a video of the wobble:
My Bosch Universal is from the later part of the 1990s. I bought it used from a place that used it for cooking classes, so it's seen a lot of use but it doesn't wobble like that.
Have you taken the bowl off and run it to see if the metal connection on the center of the base itself wobbles? If that is stable I would think the screws in the bowl might be loose.
Mine are #20 Torkx head screws but some are Phillips head. if you don't have a Torkx bit you can still probably check them with a blade or Phillips head. Torkx drivers are cheap at hardware or auto supply stores.
With those 4 screws removed you can also check two inner screws for tightness. They shouldn't cause any wobble but it's good to know how to remove them for cleaning.
Dave
I've had my Bosch for 13 years now and while my bowl is a little loose, it doesn't move that much and I use it weekly.
I wonder if the shaft is bent a little?
I also wonder if it would hurt anything to use it as is. Have you tried to contact Bosch customer service? They surely would know if it's in need of servicing.
It's a good machine, quite the workhorse so to speak. Hope they give you good news.