82 300SD heat/ac blower repair... anybody? - PeachParts Mercedes-Benz Forum

vstech · #1 11-08-2007, 12:05 PM

I can't see spending 300.00 on ebay for a replacement motor. the brushes are not gone yet, but could use a new set, and the bearings are shot. it's getting cold around here, I want some heat in the morning...
I have a spare to work on, since the one in the car works for 3 or 4 minutes before going out.
first, anybody got any tips for getting the cage off? I oiled it, and tapped on the shaft with a drift for a while with no results. am I missing a set screw somewhere?
secondly, any source for bearings?
and third, is there a source for the brushes?
thanks in advance!

vstech · #2 11-08-2007, 11:20 PM

I wonder how many times I can bump this thread before good solutions appear?
I have a large roll of tape to set the motor in so I can beat on the shaft to drive it free from the wheel, but so far, no luck.
tips, hints, outright solutions... anybody?

Brian Carlton · #3 11-08-2007, 11:24 PM

You know my solution for anything stubborn:

Heat.........apply a lot of it.........quickly..........and tap evenly on the cage.

Make sure there is no set screw.........or you have removed already removed it. Note that I have not pulled one of them so I cannot confirm it.

vstech · #4 11-08-2007, 11:31 PM

how much heat do you think a plastic blower wheel could take... and still remain a stable blower wheel that is...

vstech · #5 11-09-2007, 08:51 AM

I highly doubt everyone on here with an old 126 is going to the dealer to get the 900.00 replacement blower... nobody on here has issues with the blower motor? even to buy the ebay motor, you have to get the cage off, so somebody has to have a trick or procedure or chemical to soak it in... somebody?

Brian Carlton · #6 11-09-2007, 08:59 AM

Quote:

Originally Posted by vstech

how much heat do you think a plastic blower wheel could take... and still remain a stable blower wheel that is...

Is that wheel plastic...........???

I thought it was a steel wheel.............

No, you cannot use heat on plastic. And, plastic is a real PITA to move on steel........just a slight interference and it won't budge. I had the recent displeasure of trying to remove a plastic fan off a a/c motor for a room air conditioner. I'm sure glad the fan was already broken (single blade failure)...........because I was mangling that POS.

I think you'll have to fashion some kind of puller to apply force right on the wheel just outside the shaft.

vstech · #7 11-09-2007, 09:05 AM

any idea how that would be accomplished?

Brian Carlton · #8 11-09-2007, 09:17 AM

Quote:

Originally Posted by vstech

any idea how that would be accomplished?

The only possibility that I see is a four jaw puller that can reach through the slots and grab the back of the hub to provide even pull. The counterforce would need to be on the shaft.

The plastic is quite strong in this area and could easily take the force from the puller.

The main reason the plastic components won't release is that it's difficult to pull then with even force and they jam.

Brian Carlton · #9 11-09-2007, 09:23 AM

I would also pursue the "hammer" approach.

Support the wheel on it's periphery and leave the motor hanging beneath.

Hit the motor shaft with a large drift that is just smaller than the diameter of the motor shaft (just slips into the blower pilot hole).

I don't know how much the blower wheel can take..........but..........it does look to be a rather robust affair............and if you support it 360 degrees around it's outer rim, I don't think you can damage it.

Also, warm the plastic slightly with propane. Obviously, you know what "slightly" means..........heat it up to about 175 degrees or so...........keep the torch moving so you don't burn it locally.

vstech · #10 11-09-2007, 10:07 AM

Thanks Brain,
I really appreciate it when you respond to my posts.
I am thinking of soaking the hub in Hot water, I have no propane, just OxyAcet... and I don't trust myself using THAT on plastic...
notice the red discoloration on the top of the hub... yup. that is rust. so I am certain that rust is in there. I have the hub resting on a LARGE roll of tape, with the motor dangling in the roll center. I have stuffed a paper towel in there to catch the motor IF/When it falls out. it's no big deal if I break this one, it is my spare, but I really want to get it out.

oh, and anybody got any Ideas as to where to get replacement bearings once I have this off?

chetwesley · #11 11-09-2007, 10:27 AM

Thanks vstech for being persistent with this thread. I am also having some chilly mornings with a non-functioning blower motor... my problem is the brushes, pretty sure... any other input would be appreciated.

Do you know how to get at the brushes once you have the cage off?

Brewer · #12 11-10-2007, 09:23 AM

I just kept my eye on ebay. Got a motor with cage for $50 shipped off a low mileage junker. Playing with that fragile plastic cage did not look fun, IMO.

vstech · #13 11-10-2007, 12:47 PM

yeah, there are a lot of them on ebay, but I really want to either build mine up, or get a NEW one... I have put in a used one, and it worked for about a week. I am afraid to spend more money on used blowers.
hopefully, I will get this cage off, and figure out a method of rebuilding the motor.

hotrodrx · #14 11-10-2007, 02:15 PM

Have you checked with fap99 ? I believe Tim has one for ~ $65.00. That is motor only.

#15 11-10-2007, 07:33 PM

I can offer my experience with this issue on my 83 300SD. It looks the same as your blower motor does. I first soaked the shaft in PB Blaster (to break some rust loose) for a few hours, then supported the cage similar to how you have written except I used wooden blocks with a shop rag covering them on 4 sides. I believe the tape may be absorbing too much of the impact, but maybe not...just a thought. It took a much harder hit with a hammer and drift punch than I thought...I was almost sure I was going to crack the squirrel cage, but it never did. I was not able to find brushes but did find a replacement motor for about $60.00. The cage is an interference fit and will need to be tapped back on firmly and don't loose or remove the balancing weights(small clips) on the cage fins if you have them. They are to properly balance the unit and it will vibrate if removed or placed back in alternate location. I hope this helps.