Plastic Gears .....
 

Plastic Gears; To Grease or Not To Grease, THAT is the question.

We've talked about this many times before, some articles say grease them. Some say never grease them. Some hem and haw on the subject. So I thought I would revisit the subject now that I had some pictures to show you.
So, let me show you a machine that we just acquired. It's a mid 90s vintage Singer 3343C made in Brazil. Mostly plastic ... yuck ... but it uses the flat cams and came with a set of 30, sews nicely and we got it cheep :D . Even if the machine didn't sew, the cams are worth what we paid for it.
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A couple years ago we got a Singer 4622A. All the plastic gears were slathered in some kind of white grease. It had been worked on, that much I could tell, so I didn't know for sure weather Singer put that grease in there when the machine was built, or someone else did it later. Since it was kind of stiffish I cleaned most of that old grease off and replaced it with white lithium grease. Then later after reading a post on the Sew-Classic blog about white lithium grease, I clean the gears off again and regreased them with Tri-Flow grease.

The 3343 we got yesterday had all the plastic gears fairly slopped in white grease. I'm as sure as I can be that this machine has never been serviced. As a mater of fact it looks so clean and new inside it doesn't look to have been used much at all. The only reason I had the covers apart is the old oil had gummed up and the presser foot and ZZ parts were sluggish. They had to be lubed and freed up.

So here is a couple pics of the insides of this machine:

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Looking into the top, you can see the top shaft and vertical shaft top gear and the cam drive gear are all covered in grease. You can also see the grease on some of the internal control parts. This has to be from the factory as there are no signs this machine has ever been apart.

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Looking into the bottom you can see the bobbin drive belt set up. The other rods are stamped metal.
There is really nothing substantial in this machine.

The grease used in this machine and the 4622A looks to be the white Singer gear grease sold in their current little tubes or something very similar. After seeing these two machines, I now believe I have enough proof to support the use of grease on Singer plastic gears, so I wont' hesitate to use grease on any plastic geared Singer.
On other brands I'm not so sure yet.

Joe

My old Singer Touch-n-Sews both had the white grease on the plastic gears, so I agree with you Joe.

Kathy,

I believe our T&S 778 does too. I'd forgotten about it.

Joe

It really depends on the manufacturer, model etc. Vintage Berninas and Elnas came out of the factory with clean nylon gears. I wouldn't go off of a newer Singer model as an example of good engineering and or manufacturing practices and carry that over to different brands. As for the newer Singers, I don't care to spend time on them so I don't have to worry about their gears:>

Candace,

I do believe I said something similar to your comment on other brands in my OP. Nor do I consider newer Singers as well engineered products. I was simply relating what I've found out about those I've worked on.

I can't remember if the Bernina 930 my wife has, has any grease on the gears. The mid 90s is as new as I'll go on Singers. And those are a rarety. We basically went for this one due to the cams.

Joe

I won't have a newer Singer in the house, I'm just not a fan.

The lithium grease helps the sloppy mechanisms and cheap parts have less vibration and maybe sound a bit quieter. Most of the newer machines (all brands) have it added as the quality of the parts started going way down.

That I totally believe and agree with.


Joe

Thanks for sharing your observations Joe. I'm trying to remember if my Touch & Sews have grease in them or not.
I currently have at least two, possibly three plastic geared machines. I haven't opened my 620 Touch & sew yet to know if it does or not. The two machines I'm sure of both need their gears replaced. I'm not likely to ever be a big fan of plastic gears.
Rodney

Joe, the manual for the 478 (from 1968) states that the nylon gear should be greased. This might be different to the mid-90s models, but if you have a manual it'll tell you. If unsure, I'd apply it: Gears don't last long with no lube.

Rodney the 620 IIRC will have plastic gears. The 600 and 603 were the last with metal gears, in fact some of them were built with metal and some with plastic. You have to open them up to know for sure.
BTW, how long have you lived in Centralia? I belong to kind of a notorious family there.

Cari