Is bread flour classified by protein content?

Possibly raise the mixing bowl with a piece plywood .

A little pin or setscrew or key has failed. Maybe a gear has slipped out of place. Anyway, the thing needs to come apart to find out what happened. When taking things apart, line up each item off in a tidy row, put screws in little containers near the part they fit.
Repairclinic.com may have instructions, and probably have the parts.

take it in to an appliance repair shop for a proper diagnosis and quote but it is probably not worth repairing ( armature and brushes )

Your guess is correct. Get it cheap on Ebay.

Your mixer is easily able to handle the kneading of bread dough. Please advise:

9 cups of all purpose white flour, maximum.

6 cups of specialty flour, maximum. This is any flour besides all purpose white.

Bread doughs are only to be needed on speed 2, and never for longer than 7 minutes.

This is all stated in the Use and Care guide for the mixer itself. If these guidelines are not followed, it may lead to a product failure.

Several things:

The Professional 600 has a metal gear housing with a metal gearing. Because of this, the Professional 600 will generally run louder than other stand mixers that may have a nylon/metal mesh gearing.

How long is the bread dough being mixed for? Kitchenaid stand mixers must be used on speed 2 for bread doughs, using the spiral shaped dough hook, and mixing for no longer than 7 minutes.

If the flat beater is getting caught on the bottom of the bowl, pleasure assure the bowl is being seated correctly. You will place the bowl on the mixer arms on the left and right hand side. You will also want to take your fingers along the back of the bowl, where it butts up against the base of the mixer, and press downward. You will hear an audible click as the bowl falls into a spring latch and allows the bowl to sit flush and secure. If this is not being done, the flat beater may strike the bottom of the bowl.

If this was not the cause of the problem, please consult your Use and Care Guide about the beater to bowl adjustment. This is an easy adjustment made with a flat head screwdriver that can quickly correct the problem of a flat beater hitting the bottom of the bowl.

I dont know much about them but If you cannot get it repaired I do have a lift bowl stand mixer that I bought without the bowl or attachments that I would sell for $80.00 Or I will buy your attachments. Thanks, Mark.

Hi. You should consider a few things. They type of hook you use, can greatly affect your end result. If you're making a yeasted dough with a high protein percentage 12-13%, you should be using an "ED" hook, this is a spiral hook that has a sharp turn at the tip. You can find them on eBay for a competitive price. I believe that Hobart also sells them, but for a higher price. They are very good for mixing pizza type doughs, they also do an excellent job kneading the dough.

Have you checked the flour for lumps before it goes into the mixer? Have you tried sifting the flour?
Are you adding all the liquid and flour at once? If so try adding flour in stages to all the liquid. If you find that this solution helps you, please rate it. Good luck! ricardok45

IT NEEDS TO PROOF LONGER

Use it to the side. This will pull the dry ingredients off the bowl. If the dough is coming out lumpy, make sure you follow the recipe exactly. Putting dry into wet will give different results than putting wet into dry. If this doesn't end the lumps, try a different type of flour.