Winch brass gear is black !

[MAZ537]

Yep, I open the M125 winch (identical to wrecker rear winch) , I drain almost 12 liters of mixed black oil with grease and the bull gear is black in colour !!! I trying thinners on it but no luck the coating seems impossible to remove...
-Any idea how to clean this ? -
Maybe they have put incorrect gear oil like GL-5 instead of GL-4 and all these years cause this ?

Never seen this before...

Thank you!

 

[doghead]

Heat?

 

[MAZ537]

Hmm , I would say no as all the housing inside is covered with this black sludge...

 

[JDToumanian]

I would say you're right about the oil... That's why gear oil for manual transmissions needs the MT-1, 'synchro-safe' or 'yellow metal safe' rating, or whatever the European equivalent is. Put regular gear oil in there and it will attack the brass. The black coating is the sulphur in the gear oil reacting with one of the metals in the brass... zinc, tin, or maybe lead? I'm not sure which but it isn't going to come off easily. It would probably take some kind of acid to remove it and you wouldn't want to fill your winch with that.

Personally I wouldn't worry about it too much. If the contact surface of the gear teeth is black, maybe run the winch for a while so the teeth can polish themselves and then change the oil again sooner than you normally would.

Regards,
Jon

 

[JDToumanian]

I just saw your last post... If the whole housing is full of sludge that isn't coming out with thinners, I think I'd take the winch apart to clean it thoroughly and refer to the TM as to how to measure the gear for wear to make sure it's still okay. Over a period of years, the oil could have eaten away a significant amount of material off the gear.

 

[MAZ537]

My bad my last post is a bit confusing , I was able to clean all this black sludge from all the housing with diesel fuel except the brass gear...

 

[Tinwoodsman]

Stealth gear????

 

[NormB]

I love reading this stuff. Poked around on the web for "Sulfur and brass" (my first guess, from freshman and high school chemistry), found a really informative article on Wikipedia:

https://en.wikipedia.org/wiki/Gear_oil

Thing is, according to a LOT of the other sources, the sulfur-brass oxide isn't stable, can shear, and corrode further.

The recommendation to measure the part for out of spec condition is wise, I think.

Who knows what was used in that gearbox and for how long.

 

[162tcat]

In reality, how much winching do you do? It's likely not going to fail as I'm sure there are hundreds if not thousands of other running the same combination of soup in there and work just fine. Put the correct fluid in it and run it.


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[M543A2]

I agree with 162tcat. Since it is cleaned out put in a good gear oil mixed with STP and do not worry about it.We have done that with all of ours with no problems.

 

[m16ty]

In reality, how much winching do you do? It's likely not going to fail as I'm sure there are hundreds if not thousands of other running the same combination of soup in there and work just fine. Put the correct fluid in it and run it.


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I agree. It's not like it's a high speed part.

I run John Deere corn head grease in all my winches.