w140 Blower Motor Repair (how not to do it...)
 

So, after reading multiple posts about fixing or replacing the motor that makes cold (or warm) air blow through the vents (I was having the problem of intermittent "squealing"), so I took it apart.

First - there are 20+ little torx screws that hold the two halves of the "breather chamber" - you do not need to take these out. The breather chamber is held down by 6(?) large phillips screws, (and you might need to remove the two small torx that hold down the "access panel" in the middle)- once these large phillips are removed, the entire air chamber should lift up, exposing the top of the blower assembly. The blower assembly is held down with 6 phillips screws - remove them and wiggle it out.

The motor seperates from the housing with two phillips (easy), and the squirrel cage comes off with a firm tap on the shaft (support the cage well to avoid cracking it).

The problem with my motor was that the top bearing was worn oval - allowing the armature to rub against the magnets. I figured that there was probably little chance of finding the bushing (or getting it in without breaking something), so I decided to weld the bushing solid and then drill a new hole. Well, the bushing is rubber mounted, so when I welded on it the rubber caught on fire, which meant that I needed to weld the hole assembly solid. Then, when assembling the unit I grabbed the motor too hard in the vise, and cracked one of the magnets.

I got it back together again, and amazingly, it works a little better then it did before! It still squeals (but not as much), but I assume it will get much worse real quick. (I have a new motor on order...)

-David
92 500sel
86 560sel
85 535i
82 QPorte

I've successfully unfroze and lubed up a blower motor on a 97 S500 so I kinda know where you're coming from.

Now welding up the end bearing and drilling a new hole in it, that is nuts. I guess maybe you priced a new one? In my case, dealer quoted $600!!

But welding is fun...
 

I can order a new "motor only" for about $200, and it will be here tomorrow, so I have a safety net if this didn't work.

But, it's been a few days now, and it is better than it was, and I definitely learned something (even if it is that you can't fix this motor the way I tried...) :)

-David