Blower motor clean and lube - PeachParts Mercedes-Benz Forum

JHZR2 · #1 06-08-2020, 01:41 AM

Wanted to pull my blower motor to inspect and lube.

I was a bit surprised to find what looked like toilet paper in there. It actually worked pretty well as a filter, as it was holding a lot of dust and dirt...

I never had any complaints about airflow, but maybe removal will help... or maybe this is actually a good idea for “filtering” air given how easy blower removal is.

The blower was in great shape it seems, though dirty from brush wear.

I removed the small screw on the bottom, and pulled the motor, it was filthy. If you’re going to do this job, you’ve got to commit,and be ready for a mess. Probably good to have a hepamvac in hand too.

So, questions:

1) how do you get oil in the bushing in the top or bottom?

2) how do these brushes look? They sure left a lot of dust in there...

3) There is a decent wear ridge on the shaft/commutator; is this a cause for concern.

4) what is that very fine wire spring parallel to the commutator? Not the big heavy one.

5) can the upper bearing be reached and lubed without removal of the blower cage?

shadetreemechan · #2 06-08-2020, 07:31 AM

I have not found a way to get to the upper bearing without removing the cage.

Diseasel300 · #3 06-08-2020, 12:04 PM

Those brushes definitely need replacement. The coiled wire next to the commutator is there to suppress sparking on the brushes to prolong their life and reduce radio interference on AM stations. Zoom spout oiler is your friend for oiling those bearings. Turn the motor up on end, flood the area around the bearing and let it soak. The bearings are sintered bronze and are porous, they soak up the oil and "sweat" it out as the motor runs. There is a wool or cotton wick around the bearing that should be soaked with oil, but requires disassembling the motor to get to. Flooding the bearing and letting it soak is the next best thing.

vwnate1 · #4 06-08-2020, 02:39 PM

That T.P. has gotta go ! .

I use a flat nosed drift and 32 Oz. ball peen hammer to easily knock the squirrel cague off the shaft, this makes it easier to clean the entire thing with soapy water and get all the greasy dust off it .

The brushes are kaput, replace them .

As mentioned, the "Zoom Spout" oiler : https://www.google.com/search?client=firefox-b-1-d&q=zoom+spout+oil

Is incredible and you'll soon wonder how you even managed with out it .

It takes a chisel / punch and delicate work to remove the end frame off the motors middle part, then it's a simple thing to thourgholy clean clean the entire motor and better lube it, watch out for the delicate and easy to break thrust washers .

You're going to love the increase in air flow and reduction in noise ! .

The commutator looks rough but I've had good luck with new brushes, if it doesn't work out there's always the $100 Uro b rand new motor .

Diesel911 · #5 06-08-2020, 06:40 PM

Nice photos.
I found a surprise on mine (1984 300D Federal). It did not have a Bosch Motor.

The that lower plastic hosing on mine has Siemens 1BB52 13V and AUTOMATIK Air on the housing 28322. And in the pictures I do not see a Mercedes part number.

The Motor has the Brushes on the drive end so the Cage has to come off to take the Motor apart (I can't remember if it was 2 or 2 long bolts through it that hold the motor together).

The Cage is also different. I was afraid I would break the cage and I cut a slot on each side of the cage t relieve the tension of it on the shaft (see attached picture). Can't remember if when I re-assembled I used some glue on the shaft or not but I used a spring type hose clamp on the split end of the cage to squeeze it on the shaft.

To get at the front ball bearing I center punched the rivets and drilled them out. See post #10 for the picture.
Oh hello, number 8.

My Brushes were good. What stopped the motor was the crimped connection got corroded and you could see evidence of overheating on of one of the brushes to the Motor. I hand wire brushed it and I Soldered over it to give it a better connection.

I soaked the rear Bronze bearing in Oil for several days.

JHZR2 · #6 06-08-2020, 06:50 PM

Thanks all. I had soaked it overnight with zoom oil with no evidence of the oil level dropping or changing. Fwiw.

Someday I’ll pull it again and remove the cage and do more. It’s pretty easy to do so.

I think I have a set of brushes somewhere too. I’ll look into it. My concern was more the lip worn into the commutator.

Since it blows and works and doesn’t have play, I think I’m ok. My old 83 300D almost had a fuse box fire from the blower, so I am a bit sensitive to it!

Graham · #7 06-08-2020, 08:43 PM

My blower ran intermittently one winter. Car got very COLD. Eventually had to do something about it. Tried using cut down brushes hat were only ones I could find. That didn't work. Ended up buying a new Volvo motor that was a perfect fit and continues to work well. More in this thread for those faced with similar problem:

W123 blower dimensions

JHZR2 · #8 06-08-2020, 09:10 PM

So as of now I have no issues with the blower not starting. So I think I might have a season or two left. Probably 15 years ago I bought a set of replacement brushes that were supposedly a good fit. They’re somewhere.

Uro also sells a $104 blower. As easy as the blower is to remove, I have to wonder if that’s the better bet when needed.

Graham · #9 06-08-2020, 10:35 PM

I had to make that decision
I was lucky to find the Bosch motor in stock in Canada. With your pikaparts down there, might be worth snagging a spare. The motor cost about same as the complete uro, I think. But other than the motor, the original blower was still good. Avoided uro again. Trying to do that again buying guide rod mounts & bushings!

JHZR2 · #10 06-08-2020, 11:02 PM

Guide rods or bushings where there is significant time involved might be a good choice to err towards OE. After all, much of it lasted 40 years at this point.

But easier parts to replace might be ok going with the cheaper option. It doesn’t take more than five minutes to swap a blower.

Graham · #11 06-09-2020, 09:50 AM

Quote:

Originally Posted by JHZR2

Guide rods or bushings where there is significant time involved might be a good choice to err towards OE. After all, much of it lasted 40 years at this point.

But easier parts to replace might be ok going with the cheaper option. It doesn’t take more than five minutes to swap a blower.

You are right in that for some jobs going with Uro may be OK. I have used them. Some worked. Others like the sunroof seal, was not even close to being able to be fitted. Had to junk it and buy an OE seal. Once burned, twice shy.

And Uro does need to really be lower cost. That Uro blower costs more than the new Bosch motor I bought and likely a lot more than used blowers from pick-a-parts.

JHZR2 · #12 06-09-2020, 11:00 AM

I was under the impression the Bosch motor was still on the order of $90. And with companies like Bosch offshoring too, do we have objective evidence that any of those parts are “better” these days? Not arguing for Uro, frankly I don’t think I’ve ever bought a single thing from them.

Junkyard pulls are hit or miss and likely to have the same baggage as the pull from one’s own car. I’ve not looked to buy one - not sure how cheap they are. If they’re more than $25-30 I doubt it’s worth it.

URO Parts Support · #13 06-09-2020, 12:59 PM

Hi guys, we've been selling blower motor 123 820 1642 for just over two years, and are currently making a running change to the fan cage design. On some units, small ribs at the "top" of the current cage (at the tip of the motor shaft) can rub on the temperature control flap, increasing fan noise. The updated version won't have these little ribs.

If anyone has this fan and suspects theirs may be rubbing, it's super easy to shave down the ribs a bit with a Dremel tool. Even a hand file would work, since very little material is removed. We're almost sold out of the current version fan, and should have the first production run of the updated version in a few months.

JHZR2 · #14 06-09-2020, 03:09 PM

Thanks Uro.

Curious if you can state what the Design Specification MTBF rating of your motor is. That may help some folks on the fence regarding how to go.

Have you confirmed an exact fit of the motor casing, given that the part you mentioned was mis-dimensioned? As some have mentioned, Uro rubber parts do not always have the greatest success rate.

psaboic · #15 06-10-2020, 09:51 AM

FYI, a quick check of Rock Auto shows they are currently selling the blower motor and cage for $75.