Oil for the final drive gear housings

We use Shell Rotella 15W 40 oil in everything other than the hydraulics, some customers use 90wt gear oil,we have had good luck with the Shell product over the last 10- years,and plan to stick with it

Tommy

Affordable Tractor Sales

“Your Jinma Parts Superstore”

http://www.affordabletractorsalesco.com

I use 80W90 gear oil in my 304 Jinma.  Seems to work fine and dandy.  I don't hardly ever disagree with Tommy, and I don't doubt his experience has been good or he wouldn't recommend the motor oil, but I prefer gear oil for gears as it is formulated to have higher “cling” than motor oil. 

Motor oil is generally pumped under positive pressure to lube points while most gear boxes depend on the oil clinging to the gears to be carried to wear points.  Thus, I think an oil with high cling factor is called for.

He's talking about a dozer Tommy.

I tried to flush that black paste out of my finals but nothing would reduce it.

For the final drive lubricant I recommend and use 85w-140 extreme pressure (EP) gear oil. I use Chevron but any brand will do as long as it meets that formulation. Fill both sides up to the tattle-tale hole.

I do not want to start any oil wars but thought the oil additives for extreme pressure (EP) were unsafe for “yellow metal”.

Should we not be concerned about “yellow metal”?

Based on what I have read and heard form mechanics, we can pretty much ignore the yellow metal issue on Chinese tractors and small dozers.  That applies to synchromesh transmissions  and ours aren't.  My two favorite Chinese tractor mechanics tell me there isn't any yellow metal in our transmissions.  Further, I think that the issue of EP additives being unfriendly for yellow metals is moot now due to improvements in the lubricants.  Modern transmissions are highly stressed and need EP additives but are also all synchromesh so they have to be friendly to that.

Disclaimer: I am most assuredly NOT a real mechanic or lubrication specialists!  This advice is probably worth exactly what it cost.  Your mileage may vary, use at your own risk, don't run with scissors, wear your rubbers. etc.

Sulfur (ironically) is one of the main anti-wear and extreme pressure additives in gear oil, and that is what attacks the brass. Actually, it attacks the zinc in the brass and causes de-zincification. kinda makes it look like Swiss cheese. So be confident that there are no brass/bronze parts in the dozer final drives, and as far as I know there are none in the rest of the drive train that would come into contact with any EP gear oil.

Thanks for the information. I have printed it to add to my paperwork.

My information I think came from Greg which says something like … if it does not say safe for yellow metal, do not use it….

When I first got my dozer, I drained the GL5 I had just installed because the lab would not say it was safe for yellow metal and replaced with GL4. Live and learn!

Not knowing for sure if my tractor has any “yellow metal” in the transmission I use Super Tech 80w-90 GL-5 from Walmart.  On the label it says “protects against rust, foam, high temperature and corrosion of copper or bronze bushings.”  Therefore I assume it's yellow metal safe.

Although from what Bob said, it's the zinc that's at risk. Bronze is a somewhat  imprecise term.  It's is an alloy of copper and tin, however “commercial bronze” does contain zinc. I believe the bronze used in agricultural equipment is “commercial bronze.” Since the label doesn't specifically say brass or zinc, I'm no longer sure if it's safe (if I have brass in my tractor).

I seriously doubt there is any brass of any kind in any part of the drive train on either the dozers or the wheelies since there are no synchro clutches anywhere, and all of the bearing are ball, roller, or tapered roller. The only bearing I can think of would be the bronze pilot bearing in the flywheel.

That's the only bushing I can think of Bob, and if that one is getting eaten by the gear oil you have more serious problems than just a worn bushing.

Rich:

“That's the only bushing I can think of Bob, and if that one is getting eaten by the gear oil you have more serious problems than just a worn bushing.“

Oh yeah.

Incidentally I did find that the selector slip ring in the shuttle clutch runs on a bronze bush, and i think there maybe other bronze parts in the shuttle set up.

So there may be other yellow metal about…

I wouldn't consider bronze a yellow metal, imho. More copper, tin, silicone, and phosphorus than anything else if I remember right. Particularly sintered bronze.

Bob, you're probably right… I actually had not heard the term yellow metal before. So I presumed it was referring to the colour as a rather loose term.

So yellow metal refers to brass only? Brass from what I understand refers to any copper alloy, based around the other main other part being zinc, but in huge variation of ratios, and often other small parts of other elements. 

As for the bushing in the shuttle, I would have guessed it was some form of bronze (which I understand likewise refers to any copper alloy, based around the other main other part being tin, but yet again huge variation of actual ingredients), but it could easily be a form of brass. I wouldn't be sure, and I'm not sure how one would tell.

I'm always keen to learn more…

Just been googling yellow metal damage by oil and found this:

http://www.machinerylubricatio…..es-effects

It appears it is the copper that is attacked. So that would include copper and its alloys, so brasses and bronzes it seems.

That link didn't work for me, but the main constituent in gear oils, and particularly extreme pressure gear oils that causes problems is sulfur. Sulfur is used as a molecular binder in EP oils, but can cause dezincification in brass and it's lesser alloys. It will turn it into Swiss cheese. Most gear oils with a GL-4 rating are yellow friendly, it's the GL-5's you have to be careful of.