Gearbox croaked on the bandsaw

[Jswain]

So what is an ideal oil for this application?

I'm afraid to open the gear box, I half expect to see liquid gold again. This is what I used.

The thing to look for if you're worried about it being yellow metal safe is the copper corrosion test results of the gear oil you plan to use.
1a being very little discoloring and 1b being slightly more but still very little discoloring, anything else do not use.

Copper Strip Tarnish Test: 10 Gear & Trans Fluids

The Copper Strip Tarnish Test (ASTM D130-10) is a standard test of a lubricant to indicate how corrosive it is to copper alloys that may be in a transmission. My restored 1989 Suzuki Sidekick has brass synchromesh transmission components that may be vulnerable to additives found in many GL5...

bobistheoilguy.com

I was slightly worried when I filled my RF45 with Amsoil long life 75w90 as I believe it was 1b, so I emailed amsoil and they said it was 100% safe on yellow metal.

 

[Jswain]

So what is an ideal oil for this application?

I'm afraid to open the gear box, I half expect to see liquid gold again. This is what I used.

Just looked at the product data sheet for the Lucas and they claim it is yellow metal safe

Heavy Duty 80W-90 Gear Oil – Lucas Oil Products, Inc. – Keep That Engine Alive!

www.lucasoil.com

 

[slow-poke]

Just looked at the product data sheet for the Lucas and they claim it is yellow metal safe

Heavy Duty 80W-90 Gear Oil – Lucas Oil Products, Inc. – Keep That Engine Alive!

www.lucasoil.com

Yes, that's why I chose that particular gear oil. My assumption at the time was that the bronze gear failed because of the factory fluid. At the time I read comments on other forums that speculated that the oil used from the King factory was the main cause of the failure. IIRC the parts guy at King was implying that I might want to change the worm gear as well. Looking at the worm gear the leading edge was almost knife like so I softened that edge and reused the original.

Bronze synchronizer rings are pretty common in 4spd manual transmissions and GL4 80-90 was commonly used in those transmissions, I'm not sure when GL5 came on the market, from what I have read some (especially early GL5) played havoc with yellow metals. Some of the newer manual transmissions actually use ATF.

 

[Ironman]

On reflection to that, is your wheel brass as well? Thinking more on this, I think have seen a steel worm, but the wheel was brass.....

Steel Worm, Bronze gear, and I could replace with a cast iron worm gear
Something to think about
I'll check BB when BC wakes up.

 

[slow-poke]

I mentioned this leading knife edge finish on my worm gear. One possibility is that when the blade jams this edge acts just like a cutting tool in a lathe, peeling back the outer layer of the bronze gear as the worm gear continues while the bronze gear is stationary.

 

[Ironman]

Hey, that looks like mine

 

[Bandit]

I think they all look the same in these smaller bandsaws, maybe are all the same. The one shop I worked at also had one of these smaller saws, it to ate the gear, one of the guys cut a new gear, sorry do not remember just how it was done as was not my project at the time. That made gear done yeoman' duty for another few years at the shop, I later took that saw home where it was abused few another 20? Years with the same shop made gear. Also don't remember what lube was replaced with, with the new gear.
That little saw cut a lot of metal over the years, and very well too.

 

[wmetfab]

The other day I was sawing some box tubing on the bandsaw and things went quiet, so I assumed it had shrugged off the blade again. Shut it down and inspected it and the blade as on the wheels.
After fiddling about with the pulley I determined the gearbox was failing. I unbolted the hydraulic cylinder and removed the cover plate a thick golden oil poured out everywhere. This was a surprise as I expected the typical Chinese Yak Fat they stick into everything. How they got oil into a vertical gear box needs some pondering. After I cleaned up the mess I used my imagination to see where the gear teeth were on the worm gear. I'm guessing it is bronze

This is a King product KC-129DS and I was surprised to see a service center less than 100 km away in Camrose. If it is a bronze gear and the Yak fat is incompatable, that would explain the faiulure.

Hi, just out of curiosity, what are the heaviest sections you normally cut in your saw.
Do u use any lubricant/coolant whike cutting?

 

[Bandit]

I don't use lube/coolant with mine, I will cut what ever I can get into it, some times May take a number of cuts around, over to get it done. Sure saves the arms, I can watch it work no problem. LOL lots.

 

[Ironman]

I tried to contact the HO of Busy Bee, they put me on hold and then wanted me to leave a message. Not.
Today I was in Edmonton for a liver exam, and I darkened the door of the local BB. Been 7 yrs since I wasted time there. I came in and a woman came up to me and I told her I wanted a worm gear for the CX166 and the number on the diagram was 50. She whipped up the computer and said we have one in stock, I think. And jogged off to get it. And it was the right thing for 67 dollars. Could have blown me over with a fart.
I told her what I thought was the problem, too much Yak Fat. She said she does the rebuilding on the milling machines and she said I was right and she now puts Lubriplate in the gearheads. I told her I was a metalworker and that's why I never come here. She said that the previous manager was a woodworker and he filled the place with planers and sanders. She said when she took over the store, she started pushing that stuff out the door, and all her customers are metalworkers because she is an oilfield machinist.
Wow. She said please come back and see what I'm doing here.
So here is my old gear and my new gear. Hot damn!

 

[DPittman]

I tried to contact the HO of Busy Bee, they put me on hold and then wanted me to leave a message. Not.
Today I was in Edmonton for a liver exam, and I darkened the door of the local BB. Been 7 yrs since I wasted time there. I came in and a woman came up to me and I told her I wanted a worm gear for the CX166 and the number on the diagram was 50. She whipped up the computer and said we have one in stock, I think. And jogged off to get it. And it was the right thing for 67 dollars. Could have blown me over with a fart.
I told her what I thought was the problem, too much Yak Fat. She said she does the rebuilding on the milling machines and she said I was right and she now puts Lubriplate in the gearheads. I told her I was a metalworker and that's why I never come here. She said that the previous manager was a woodworker and he filled the place with planers and sanders. She said when she took over the store, she started pushing that stuff out the door, and all her customers are metalworkers because she is an oilfield machinist.
Wow. She said please come back and see what I'm doing here.
So here is my old gear and my new gear. Hot damn!

Wow that's amazing BB was so positive, things are looking up maybe.

 

[Ironman]

Now all I have to do is find the time to replace it. Garlic is just starting to scape, another week and we'll be cutting them.

 

[Ironman]

Hi, just out of curiosity, what are the heaviest sections you normally cut in your saw.
Do u use any lubricant/coolant whike cutting?

I never use coolant, what mess that stuff makes.
I have sawed 5 inch round stock, 4" square, and 2x3 FB, and often oilfield pipe, which is a high grade of steel so the bandsaw is preferable to the cold saw. I use a 10-14 tooth bimetal blade and in deep thick cuts it clears the debris well. Aluminum, well that's a bastard with the variable tooth and I have to use WD40 spray to keep it going.

 

[PeterT]

So that's what's in the gear case huh? $67 sounds shocking but it closely resembles what's in a lot of Asian lathe aprons & when they are worn. They can be a real bugger to source as in unobtanium. And not exactly trivial to make yourself. You can get metric worms & matching worm wheels but not as readily in those shorter, somewhat less common, center distances & hub & key dimensions. Personally I'd buy a spare while they are still available especially if they are known consumables.

Precision Worm-Gear Sets – Maedler North America

maedlernorthamerica.com

 

[PeterT]

@Ironman how many teeth & what module is the brass/bronze worm wheel?

 

[Ironman]

So that's what's in the gear case huh? $67 sounds shocking but it closely resembles what's in a lot of Asian lathe aprons & when they are worn. They can be a real bugger to source as in unobtanium. And not exactly trivial to make yourself. You can get metric worms & matching worm wheels but not as readily in those shorter, somewhat less common, center distances & hub & key dimensions. Personally I'd buy a spare while they are still available especially if they are known consumables.

Precision Worm-Gear Sets – Maedler North America

maedlernorthamerica.com

View attachment 49055

Actually No, $67 is better than King Canada's wait 3 months and pay $87, or Jet's pay $120USD plus shipping from the states.
A worm gear is an easy thing to make if you have a spare worm to cut into a hob and let the worm gear blank rotate against it.

@Ironman how many teeth & what module is the brass/bronze worm wheel?

20 teeth, and I don't know the module, I have metric hobs and will get that sooner or later.

 

[PeterT]

A 20T 1.5 module gear on McMaster is 56 USD, presuming the hub will work dimensionally to re-bore & keyway slot etc.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

Yes, I watched a bunch of videos on home shop hobbing thinking that might be in my future one day. If you don't want to sacrifice your worm, probably best to turn a new lookalike as a dedicated cutter for repeatability. The cutter, the turning, hobbing, slotting... looks like an afternoons work. Which... (using my own personal home shop correction factor) probably means a week or more haha. Fortunately I have a spare. If you have the hobs you should seriously flog gear wheels on Ebay & forums. So many guys with clapped out Asian lathes using power feed sparingly or not at all because their gear has turned to mush. Now the trick is always, what were their original dimensions. I was comparing notes with a guy who has 90's vintage 14x40 same size as mine & his worm wheel is different. I think he has a collection of 6 now from Grizzly & Emco & other suppliers. Same tooth count & PA, but all slightly different. His lathe is a misfit. Obviously they made their own gear, maybe on a worn or misfit cutter.

 

[PeterT]

My lathe power feed gear

 

[Ironman]

I measured my new gear, 47mm. The module is not something I'm certain of. I tried my set of metric cutters and they were not near enough. An inch #5 is very close and starts at the 21 tooth range. A 20 would probably do it, but I just bought the individual hobs I needed for the gears I have cut so, no 20 tooth.
There may be a better way to find the module, I don't know it.
EDIT
dug out the formulas so 47mm /2+20= 2.13

 

[Ironman]

I decided to use this stuff and just ordered it from Amazon