Sticky motor sheaves

[mnnance3]

I purchased a used 500. The seller told me it had a motor problem.

I opened it up, and found that the motor sheaves are stuck in the high speed position.
I removed the motor pan, pulled the spring and was able to split the two sheaves. I removed both sheaves and the long key. There does appear to be a spacer at the motor. It is fixed in place and not just a loose "washer" as I expected.
Anyway I cleaned everything up and applied some light lubricant.
Without the key in place both sheaves move easily on the shaft and do not stick. Adding the long key things move well but they stick together when I slide them together as far as they go.
Examining the floating sheave, it appears that it has a brass bearing that is pressed or soldered in. If this has moved, it could be causing the problem. Is this a common issue? Is it enough to replace the floating sheave or do I need to replace more parts? Is there more to be tested to know for sure.

[wa2crk]

Welcome to the farm!!!
You are off to a good start because you were able to take it apart and put it back together.
I don't think that there is a bushing in either of the sheaves. There is a spacer on the motor that keeps the fixed sheave from moving and contacting the bearing in the end of the motor. Carefully check the sheaves to make sure that they are actually binding against each other. This can happen if the PO mixed and matched the sheaves from different machines. (A rare occurrence).
What I think may have happened is that lack of lubrication may have produced some burrs on the edges of the keyway slots or on the key itself.
My best advice is to disassemble everything and make sure there are no burrs on the key or the keyway slot on the motor shaft. If there are burrs on the motor shaft file them with a fine jewelers file Also clean out any old oil and gunk from internal bores of both sheaves and don't spare the oil when reassembling. Personally I like to mount the motor on a workbench and polish the motor shaft.
If the sheaves are actually contacting try to mark the areas and sand or slightly file the contacting surfaces. Lack of lubrication over a period of years will wear the keyways in the sheaves causing a slight mis-alignment.
If you have a problem come back here.
Bill V

[mnnance3]

I watched the online videos a half dozen times before diving in.

The reason I thought the "bushing" in the floating sheave was press in was appearance. It appeared to me to have a bronze interior and aluminum body, while the fan sheave looks to be all one material (aluminum)

Floating Sheave

DSC_3570_1.jpg (93.67 KiB) Viewed 1866 times

floating sheave inside

DSC_3569_1.jpg (108.02 KiB) Viewed 1866 times

[wa2crk]

Sorry I can't open the pinterest pix. I haven't caught up with all of the attributes of this new format yet. The pix should be able to be uploaded to the forum directly.
Bill V

[JPG]

I believe the floating sheave has a steel hub/bore with the aluminum sheave cast onto it.

[wa2crk]

JPG is correct, that "bushing" can not be removed.
The pit marks on the one sheave are interesting. Looks like the belt has sat in one position for a very long time. Try to remove them with some fine sandpaper. DO NOT GET TOO AGGRESSIVE!!!
When returning the fixed sheave on the motor shaft it should move along the shaft easily with very little wobble. Slide the floating sheave along the motor shaft with the key in place and there should be no binding.
Bill V

[JPG]

Sorry I can't open the pinterest pix. I haven't caught up with all of the attributes of this new format yet. The pix should be able to be uploaded to the forum directly.
Bill V

Not 'you', but a result of admin working methinks.

Now about this pinit/pinterest stuff?????? Whazzat???

[mnnance3]

Yes, the roughness makes me think it tried to run for a while.
I slid two small screw drivers along either side of a "finger" on the floating sheave. I'm not sure what moved, but the "stickyness" seems to be less pronounced than it was. Still present, but less.
I have cleaned the mating faces of both sheaves with denatured alcohol and they are pretty clean. I no longer think they are sticking due to anything on the surfaces.
Since the Fan sheave is all aluminum, while the Floating is 2 materials (steel hub/bore with aluminum body) I am actually wondering at this point if the Unit sat running and got hot enough (from friction from the belt) for the aluminum (lower melting temp that the steel "hub") to melt a bit and move on the bore. That could explain the pitting and the apparent misalignment. I am also noting what appears to be some type of "aluminum looking" flow at the mating surface between the body and the "bore", as if something melted there.
So I'm thinking of replacing the Floating Sheave (which to my mind seems a likely culprit) and the long key (just in case there's anything going on with it). worst case I will have to go back and replace the fan sheave if the problem remains

[wa2crk]

That "smear" appears on all of those sheaves and is a result of the manufacturing processes, In short as we used to say in Brooklyn "fuggetaboutit".
Bill V

[JPG]

That 'smear' was not caused by 'melting' there, but rather by 'solidifying' there! ;>|