Which w123 Blower Motor is Rebuildable?

[bustedbenz]

I pulled the blower motor out of my 240D last week in response to the fact that it randomly started behaving oddly. I'd have the fan speed set to high, like usual, and the fan seemed to have a mind of its own. It would blow at high for a while, and then sort of slide (not sudden changes) gradually down to something slower than low, and then just when I was starting to notice the temperature climb, it would speed back up to maybe medium or medium-and-a-half, and then 5 minutes later it'd slide back down to almost stopped -- etc. The fan speed fluctuated, so I took it out.

On all the blower motor threads I've found so far (yes, I used the DIY link to blower motors) the general consensus seems to be that there were a whole lot of different blower motor styles that were used year to year, and that *some of them were more rebuildable than others*. What I need help with is determining which category mine is in.

I suspect that worn brushes in the motor are why mine was acting erratic. They look just about gone visually, and several threads said that brushes could produce a number of odd symptoms. My first thought was that if the fan bearings were wearing out and producing too much friction, then the speed changes were caused by the fan heating up and partially seizing and then cooling back down. But, when I got it apart, the brushes look so close to gone that I think I have to suspect them first. It turns smoothly by hand, for what that's worth.

So here's the question. The motor I took out is a Bosch. The brushes are sorta-kinda visible in their holders, now that I have the motor out of the plastic mounting housing. But, they do NOT look changeable or replaceable. The brushes are hard-wired to their connecting wires, and the holders that retain the spring and brush assembly look like they'd break if I pried the end open enough to slide the spring and old brush out. They don't look removable, in other words.

Is this Bosch with the semi-permanent brush installations the one that "can be rebuilt" or the one that everybody says "don't bother, you need to replace it."

I brilliantly went to pull-a-part two days ago to see what I could find to replace it with, on the assumption that mine is not rebuildable. They had a Bosch in a 300D, but its brushes were just as worn out as mine so I didn't bring it home. What I did bring home was the Siemens blower motor out of a 1980 240D. I thought at the time that, since my Bosch was not easily rebuildable, the Siemens must be the one that's easy to get to.

Um... no. The siemens is encased from top to bottom in what seems to me to be an impenetrable metal casing. And so I plugged it in, figuring I'd at least test it, and if it worked, I'd use it for however long it gave me while I figured out how to rebuild the other one in the meantime. Figured what were the odds that I'd get a completely dead replacement by random junkyard selection? Well, I did. Doesn't even twitch or hum or explode or act in any way as if it's alive. I know it's getting power because I plugged my old one back up in the exact same way and it worked instantly. :-/

***THE ACTUAL QUESTION*
So now I don't know. What blower motor do I have to find in order to be able to pop brushes out and stick new ones in? Is my Bosch with the permanent spring retainers the "rebuildable" one? Am I just going to have to pry the metal fingers at the back of the brush holder open on the Bosch unit and hope I don't break one of them off before I get it back together? Is there something I'm missing about how the Siemens unit comes apart?
***

Thanks. I just paid a shop to find the obvious a/c hose leaks and then recharge the system, and I had about 2 weeks of air before the blower started acting up.

Oh, and this 240 has the 3-knob control unit. Not a 5 button push box computer thing.