Heater fan motor lubrication ?

[66andBlue]

Time has come to put the heater core and fan assembly back in - last chance to lubricate the motor.
 :?:  Is it possible and easy to lubricate the fan motor without taking it out of the housing? :?:
I read somewhere that the cage fan blades break easily and are hard to remove.

Download Attachment: BlowerMotorHousing.jpg
33.83 KB

Alfred
1966 blue 230SL automatic

[jeffc280sl]

There is no lubrication hole/location on the motor itself.  The motor shaft rotates in brass bushings which are located in each end of the motor housing. Inside the motor and underneath the bushing there is a washer and then a felt washer.  Lubricant trickled down the motor shaft may penetrate enough to lubricate the bushing/shaft connection. The felt washer under the bushing is almost impossible  to with oil without removing the blades and taking the motor apart.

The fan blades are brittle and difficult to remove.  Great care must be taken when trying to do so.  There is a allen set screw on each side that can be removed.  The fan blades are often stuck on the motor shaft and the connection must be very well lubricated to have any chance of removing a stuck fan blade intact.


Jeff C.
1970 280SL 4-speed

[al_lieffring]

When I replaced my blower fan motor it cost around $500 for just the part and that was back in '79. It would only run on the high setting, then one day smoke came rolling out from the defroster ducts. I was using the car as my daily driver and after blower quit the temprature dropped down to 0 deg (f) the next morning.  

Al

66 230sl
113-042-10-014715
904/396 blue, Ivory Tex
condition: not-as-rusty-as-before-bucket

[Shvegel]

Speaking as a former BMW instructor and lifelong mechanic(not bragging just want to let you know my experience level).

I tried to pull my motor apart and lurbricate it because it was noisy.I have probably done this a hundred times before on small motors on various old cars but it was a pain and I ended up destroying it. Not an overly difficult job for me but 40 years of corrosion etc just made it a bad day.

I seem to remember that in getting the fan wheels off I had to drive the shaft out with a punch and hammer which caused the end of the shaft to mushroom slightly which then caused the shaft to stick in the bushing and destroy them. I guess if you used a small press and were carefull you might get away with it.

If it wasn't for Pete Lester who was kind enough to give me another one it would have been a far worse day than it was.

I guess if it were me I would try dribble oil on the shaft and see if you can get it to work in that way. If the case isn't tight to the shaft and you can see the bushing you can push it down slightly and get oil into the bushing that way or drill a small hole in the bump that the bushing rides in and fill it from there. You could just epoxy it up later. I wouldn't  use WD 40 because it is too thin and it dries up. I would just use good old 3 in 1 or some 10w oil.

[66andBlue]

Jeff and Shvegel,
thanks for the helpful comments.  I took a closer look and cannot find a set screw on the outside of the fan wheels only on the inside (see pic). Is that correct?
I took the inner one off on one side and the wheel is stuck!  
I'll dripple some oil on the shaft where it enters the motor.  At this point I'll take a chance and put  the old motor back in, it ist still spinning freely.
But just in case.  Jeff, where did you buy new fan wheels? The motor can be bought for about $60 with shipping.

Al, guess what a new one costs now?  SLS lists the motor for $1,610 and one blower wheel for $254 = $2,118 for the total. Now if that is not ridiculous !![:0]  Bud's wants $1,490 for the motor.

And here a question for all 3 of you. Should I worry about the crumbling foam and try to replace it?
Thanks for all the help!
Download Attachment: Blower Motor.jpg
60.97 KB

Alfred
1966 blue 230SL automatic

[jeffc280sl]

Now I feel better because others have learned about this the same that way I did.  Unfortunately that means breaking somethings which I did in the case of the fan motor.

Jeff C.
1970 280SL 4-speed

[graphic66]

I believe that there is a place on each end of the fan cage for a set screw so the fan cage will work on the right or left shaft. I just put lightwieght oil on the shafts and turned and wiggled the shaft side to side with the motor standing to allow gravity to help.

[66andBlue]

quote:Originally posted by graphic66

I believe that there is a place on each end of the fan cage for a set screw so the fan cage will work on the right or left shaft...

Thanks .. now I get it! *-:)

Alfred
1966 blue 230SL automatic

[jeffc280sl]

Alfred,

I was eventually able to get one fan side free and removed in tact.  The other side was cracked and I glued it back together with some epoxy.  Works fine.  I was never able to find a squirrel cage fan with the correct dimensions so I repaired and reused the old ones.

If I were to do it again I would remove the set screw and clean the exposed shaft with steel wool and use penetrating oil.  I would use penetrating oil in the set screw hole also.  You might be able to press one side in to expose some fresh shaft metal and then clean the surface again and re-oil.  

As discussed you need to be carefull when tapping on the end of the shaft as you try and support the fan from underneath..  I would use a plastic hammer so you don't mushroom the end of the shaft.  Be carefull with the opposite side of the fan when tapping the shaft. That's how I broke one of the fans.  I think if you are very patient and work slowly over some days you will get it free.

I don't think the old foam is a problem.  I cleaned and painted the assembly and when put back together I used some foam material from Home Depot.  I think the foam is used to help steer air from the inlet to outlet.  Any openings not insulated or blocked with foam would decrease the fan effect slightly.


Jeff C.
1970 280SL 4-speed

[66andBlue]

Thanks Jeff.
Since I couldn't get the set screw loose on the other side I gave up and dribbled oil on the shaft a few times. I’ll take a chance and put the old motor back in.

Alfred
1966 blue 230SL automatic

[George Des]

If the original motor is not too far beat up in the process of dismantling the blower unit, it can be rebuilt to include rewinding the armature/field windings and installing a new commutator and brushes if the internals are burned out. A rewound armature with new comm is about $75-$100. The brushes are essentially the same size as those used on the newer style electric fuel pumps. No need to tell you how expensive a new motor is if you can even find one. I'm sure aftermarkets can be made to work, but for those striving for originality, a rebuild may be the only alternative.

George Des

[enochbell]

And if you are really in a pinch I have a spare unit, complete, I can part with.

Best,
g

'64 230sl, fully sorted out...ooops, spoke too soon

[Chad]

Reading through this thread has convinced me that I should not  even touch the heater blower motor - it works fine at different settings and is pretty quiet. The flow of air may not have been very strong for a modern unit but the car is forty years old.  Better leave well enough alone than remove and destroy what is for practical purposes an unobtainable part.

1967 230SL

[seattle_Jerry]

If the foam is crumbling and it is easy to get to...it should be replaced. Otherwise you will eventually get foam dust blowing out the defrost. I had that happen on my '70 220D. Its annoying to get foam in the eye when you are driving.


1967 230SL Havana Brown Auto with A/C