Which oil for wobbling tonewheel?

[geldo79]

Hi,

some frequencies in my m3 have a wobbling sound. As they all are on the same gear, i always put some wd40 on it. Then, all tones are ok for lets say 2-3 month, but then the wobbling always comes back. Using hammond oil did not have any effect. Is there another oil i could use...or something different. I also have deoxit here....can i use that? Would like to get rid of that problem...

greetings Christian

[Drawbar Dave]

Are you able to see if the oiling wicks are intact when you are applying WD-40 to the offending tonewheel?

[tiredoldgeezer]

WD-40 does everything well.... for a month or two.
This is why it's generally thought of as a stop-gap measure in tonewheel work. It will get through to help liquefy the thick scum, sure. But for long term oiling it's actually a poor choice and I think you're seeing why.
WD (water displacement) is its specialty and it does that by going in thin (we've all seen that) and then when the lighter aromatics have evaporated, leaving behind the heavier paraffins forming a 'waxy' seal to keep the water out. Dandy for machinery and ignitions. Not so super for delicate rotating parts.
Hammond Oil is the best and safest way to go. But Hammond Oil doesn't cut through the goo except after months and months. Who wants to wait that long?
A shot of any super-light solvent on the offending bearing, followed up by a drop of Hammond Oil is a really good process. But the generator generally has to be out of the case to do a complete job.
In your case, I might be tempted to glug a capful of Naphtha into things. Let it run. When that tiny little chirp of dry bearing is heard, jump on it with Hammond oil.

[geldo79]

Thanks for your advice. But I really don't exactly know what naphta is.....google says it's something like petrol?! Don't know what it is called here in germany )-:

[handyczech]

Naphtha is essentially paint thinner used to clean brushes or oil based varnish. Another popular product to use for this purpose is liquid cigarette lighter fluid, usually sold in square tins with a pointy spout. I argue for using medical grade mineral oil as Hammond itself specified as an acceptable substitute in the 1930's, but that debate rages on. Either flush with naphtha or cigarette lighter fluid, sop up any dripping with pads or paper towels, removing those from indoors immediately due to fire potential. Follow up with a thinned mixture of the Hammond or mineral oil, and then a dose of all oil. These steps may require patience and time. Allow time for the solvent to clear, then allow time for the thinned and then finally the regular oil to seep through everything. You probable should avoid flushing or overoiling the scanner, but others may suggest otherwise.

[geldo79]

Ok..thanks. I'll try with lighter fluid. But how could i overoil the scanner? I'd put the fluid/oil directly on the gear. That's what i have also done using wd40. And the scanner has its own oil reservoir anyway...!?

[tpappano]

Going back to your original post you refer to "wobbling" tones that go away for a while after being sprayed, but come back again. Do you hear this on single tones, that is only one drawbar pulled out? And, do some notes wobble while others are clean sounding? There is a symptom many call "fluttering" tones, it's as if a particular tone has its own fast vibrato effect. This issue is separate from bearing lubrication and can be caused by sticking of the spring-clutch arrangement that each tone wheel pair has. The treatment is thoroughly cleaning the spring clutch by spraying it with a good zero-residue degreasing solvent to flush out old sticky residues. Probably before I go deeper into all this, does this sound like what may be happening? It is most noticeable on the higher frequency tones and can sound pretty irritating 8)

[geldo79]

I hear that wobbling sound on notes d#3 and d#4 when only the 3rd drawbar is pulled out (fundamental). From the service manual i see that this should be the frequencies 52 and 64....which are on the same shaft. It sounds like a vibrato effect like you describe.

[valotus]

I hear that wobbling sound on notes d#3 and d#4 when only the 3rd drawbar is pulled out (fundamental). From the service manual i see that this should be the frequencies 52 and 64....which are on the same shaft. It sounds like a vibrato effect like you describe.

In the worst case scenario faulty bearing causes tonewheel shaft to wobble: https://youtu.be/aTjApu1TOmY

That sure is what it can be at worst, but also a lightly worn bearing will make tones fluttering, especially when there is lack of oil so that end of shaft can do radial motion.

To get correct diagnose you should see and move the actual set of wheels, which in this case is a bit challenging as tonewheel pair 52-64 is located backside of generator. It may be possible to get there thru narrow gap under filter tray with a dentist's mirror and some suitable tool to move them. Anyway, I personally would prefer getting the generator off on the workdesk, or at least tilt front side upwards so you can see under it. But as you said you have sprayed WD-40 to gear (not bearings?), so you may already done that?

[geldo79]

I did not remove the generator yet. I was always able to spray the wd40 to the desired position using a flashlight and by looking through that narrow gap under the filter tray as you described. Not easy....but it worked. But i always only sprayed the gear....not the bearings. Would spraying the bearing help in case if a worn bearing? Of course it could be that some of the wd40 found its way to the bearing too, as i always used enough wd40 (-;

I'll have a look at the necessary steps to get the generator off. I recently removed the upper manual chassis. Removing the generator could be easier...i hope (-;

[tpappano]

On a M3 you can prop the “back” (the side closest to you) of the generator up with blocks which can give you access to the underside. You can reach the wheels with your fingertips to check for sticky clutches. No need to disconnect or remove the TG quite yet.
I should mention that wd40 will likely make a “sticky clutch” problem worse rather than better, since it leaves behind a sticky residue that will build up with continued application.

[D1gichip]

Remember WD40 is not really oil. It is called a lubricant, but not for true lubrication. Temporary fix only. WD40 was designed as a "Water Displacement". 40 is the 40th formulation. (Actually I think it's up to 41, but it's the name now.

[geldo79]

Thanks so much for all your hints. Never tried to prop up the generator. Seems like a good idea. I'll have a look at the corresponding tonewheels and bearings. Hope the bearing is not worn. In case of a worn bearing....are there spare parts abailable somewhere? And is it possible at all to replace a worn bearing?