Correct Transmission Fluid?

https://www.napaonline.com/en/search?text=mineral%20gear%20oil&referer=v2


Edited by jaksjep - 06 Feb. 2023 at 9:49pm

I use the a Tractor Supply GL-1, it seems to work just fine.

Jerry45 wrote: not to beat a dead horse on this is thread, but I'm gonna replace the transmission and transfer lubricant and though this thread seems to point to using GL-1 for the transmission, the manual states GL-4 is recommended.  Simply put, should I just order the GL-1 from NAPA?

Edited by srlbotanical - 30 May 2018 at 7:14pm

I did some looking into my chem books, and I have found what I think is the answer to our sulfur lubricant quandry.  The lubricants are made from Sulphurized long chain fatty acids, which means several long chains of Hydrogen and Carbon which are neutral, with a polar head group, composed of Phosphorus, in this case Sulfur, and oxygen.  These transmissions, being unsealed to the atmosphere, allow minor amounts of water vapor, found in the air, to reach the surface of the oil.  If the sulfurized fatty acid has a double bond located near the sulfur, it can convert into what is known as a resonance structure, meaning the double bond can move between two or more different locations.  During this resonance, the Hydrogen attached to the sulfur becomes weakly bonded, and can be picked up by the oxygen in the water vapor, producing a weak acid, but an acid none the less (H3O).  This acid dissolves the tin in the bronze, forming a salt, and the copper is left over undissolved, hence the coppery fluid that you end up with (tiny bits of copper).  Finally, I'm including an example reaction to show the production of the acid.  Without the resonance, the hydrogen is very difficult to detach from the sulfur, and so will not produce acid, and will not eat the tin.  Hope this helps explain why some are bad and some are good. 

Older post I know but this site (http://www.widman.biz/English/index.html), while in Bolivia, has a couple of good white papers on gear and engine oil, as well as interesting in general. The white papers are down at the bottom of the page but I think these links will work...

"Selection of the Right Motor Oil"
"The difference between GL-4 and GL-5"

Warren

Samcj2a;

Nice chart!  I'm stealing that.   :)

Your description regarding ISO vs SAE jogged some of my brain cells.  As they say, "it all started to come back to me"!  However, the chart is real nice.

I saw that oil in Tractor Supply after reading this thread and wondered if it would be OK.  I think I might give it a try.  It does seem to be another option.

Thanks again ... great stuff and a great thread.

What about this oil sold at Tractor Supply for Ford tractors??

http://www.tractorsupply.com/traveller-reg-ford-tractor-all-mineral-90-transmission-fluid-2-gal--0806600

Is this stuff the correct viscosity?  Or is the GL 1 NAPA oil the only choice right now??

Great thread by the way .... !!

Carlsjeep wrote:   You may want to flush the tranny and transfer cases with kerosene. Jack the rear wheels up and run it in high gear a few minutes at idle to stir it up and drain it. Don't drive it with the kerosene in it. Two minutes or less should work. You may have already damaged the blocking rings and only time will tell.

   Pennzoil Synchromesh Manual Transmission Fluid. 

  Has anyone checked out this stuff?   According to their website; "It provides excellent oxidation stability, low temperature performance, excellent synchronizer performance and compatibility with yellow metals, such as bronze, brass and copper components found in manual transaxles and transmissions."  an aanlysis of the oil found that "consist of a 5W30 non-detergent oil with a friction modifer and an EP (extreme pressure) additive". The use of EP additives concerns me.

   More details can be found here http://www.stealth316.com/2-pennzoil-synchromesh.htm