GL5 oil

[OK8N]

Just wanted to post a reply I got from Mystik regarding the use of their JT-7 oil in a 48N.
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"Mystik JT-7 SAE 80W-90 Multi-Purpose Gear Lubricant is an API GL-5 performance level, indicating these oils have high levels of Extreme Pressure (EP) additives. High levels of EP additives can react at high temperatures with yellow metal components such as brass bushings and bronze syncronizers in transmissions. Most transmissions that specify a gear oil will specify an lower level of EP additive such as API GL-3 or API GL-4."
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Not too worried about high temps in the diffy or trans, but I'm thinking the hydraulic pump might create the conditions necessary to cause the EP additives to react. So I'm going with GL-1 mineral oil.

 

[TheOldHokie]

(quoted from post at 10:29:56 02/26/11) Just wanted to post a reply I got from Mystik regarding the use of their JT-7 oil in a 48N.
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"Mystik JT-7 SAE 80W-90 Multi-Purpose Gear Lubricant is an API GL-5 performance level, indicating these oils have high levels of Extreme Pressure (EP) additives. High levels of EP additives can react at high temperatures with yellow metal components such as brass bushings and bronze syncronizers in transmissions. Most transmissions that specify a gear oil will specify an lower level of EP additive such as API GL-3 or API GL-4."
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Not too worried about high temps in the diffy or trans, but I'm thinking the hydraulic pump might create the conditions necessary to cause the EP additives to react. So I'm going with GL-1 mineral oil.

You have your concerns backwards. The "diffy" is exactly where you get that "high" temperature. And in this case "high" is something on the order of 250 to 275 degrees Celsius. That is truly hot, 480 to 525 degrees Farenheit. That extremely high temperature is produced when the oil film between the ring and pinion gear teeth breaks down and they come into sliding contact. The frictional heat produced by that metal to metal contact raises the surface temperature of that tiny gear tooth contact patch to the EP activation temperature. The EP additives then react with the hot metal surface of the gear teeth to form a protective layer of oxidation [u:be279b21c3][b:be279b21c3]but only at that tiny contact point[/b:be279b21c3][/u:be279b21c3]. Meanwhile the gearbox oil temperature remains somewhere in the neighborhood of 200F or less.

The hydraulic pump on the other hand has only a few brass bushings on the PTO shaft and the surface loads are orders of magnitude lower. I would be very surprised if the surface temperature of those components got even remotely close to the activation temperature of the EP compounds in GL5 oil. And as long as they remain below that activation temperature they do not react to any significant degree with the bushings - e.g. the oil remains yellow metal safe.

Notice that the response you got from the Mystic tech support folks mentions synchronizers. That is a yellow metal component that does see high surface temperatures as they are basically jammed into sliding metal to metal contact with spinning gears to equaize their rotational velocity when the gearbox is shifted. And that temperature causes the EP compounds to react with the surface metal of the bronze rings resulting in excessive synchronizer wear. In that application the oil is not yellow metal safe. There are no synchronizer rings in an N series tractor.

TOH

 

[souNdguy]

i'd skip the mystyk.. it's too easy to find gl5/mt1 oil that is yellow metal safe for the N pump.. way too much of it out there to not to..

soundguy

 

[Dunk]

My '49 8N lift does not work well at all on the GL1, like mole asses on a cold MT morning outside, it has always been that way (30 years), I have tried it (GL1), a few times.

Changed it from metal rings to the O ring, and replaced the cam pin, in that amount of time.

Lift was might near usless with GL1.

It works wondeful on the other, unless I really overwork the lift. and that takes some doing, just riding around with the bush hog lifted won't do it, and it is pretty heavy.

It usually takes pulling hedge stumps, or something like that, with a chain on the scrape blade.

Then it is fine, after it cools.

Sometimes I have ran half, and half, to get rid of the GL1

I wish I could understand the reason for that, and that everyone else seems to like GL1.

 

[Dunk]

(quoted from post at 19:39:17 02/26/11) My '49 8N lift does not work well at all on the GL1, like mole asses on a cold MT morning outside, it has always been that way (30 years), I have tried it (GL1), a few times.

Changed it from metal rings to the O ring, and replaced the cam pin, in that amount of time.

Lift was might near usless with GL1.

It works wondeful on the other, unless I really overwork the lift. and that takes some doing, just riding around with the bush hog lifted won't do it, and it is pretty heavy.

It usually takes pulling hedge stumps, or something like that, with a chain on the scrape blade.

Then it is fine, after it cools.

Sometimes I have ran half, and half, to get rid of the GL1

I wish I could understand the reason for that, and that everyone else seems to like GL1.

Pulling metal fence posts out of this GA clay, with roots grown around them would do it too, before I learned the chain over 4x4 trick.

 

[TheOldHokie]

(quoted from post at 18:47:51 02/26/11) i'd skip the mystyk.. it's too easy to find gl5/mt1 oil that is yellow metal safe for the N pump.. way too much of it out there to not to..

soundguy

Point me to a product that you feel is "yellow metal safe". I'd like to compare it to the Mystik product.

TOH

 

[Tom N MS]

Yea, piece of oak 4 X 4 is lightwer and easier to deal with than the truck rim but both work.

 

[Hobo,NC]

I have never seen were 80/90 gear lube has ever damaged any brass parts,,, other than a chitty European sports car...

You can run that thick stuff if you wanna but 80/90 is far superior. Best I remember around 1990 I rebuilt the trans in my yota (5speed),,, put 90 wt in it as it had been the norm,,, you could not shift the gears cold,,, my yota dealer bud brought me some 80/90,,, it was a instant fix,,, from that point on I have used 80/90 were 90 went and never a issue... 80/90 has the same effect on a N,,, far less drag,,, yer N will B ready to go to work cold...

 

[JerryS]

What's your technique here, Dunk? I'm guessing you prop up your chain with a short length of 4x4?

 

[Anonymous-0]

Thanks for the great info TOH. Been wondering since I changed out the oil on my '47 8N last summer & used 80w90, GL-5. It must have had the 134 stuff from PO as the pump now is much quieter & lifts a 6' (6.5'?) disc easily. Don't know about cold weather operation as the old girl is sleeping soundly at our cottage until Spring.

 

[Dunk]

(quoted from post at 23:24:14 02/26/11) What's your technique here, Dunk? I'm guessing you prop up your chain with a short length of 4x4?

Yes, and then hook it down low on the post, to where when the tractor pulls (drives forward), it is really pulling nearly straight up on the post.

It helps to lean the 4x4 just a bit toward the post.

It would be great to saw a V notch across the top of the post.

I just usually grab what is handy.

 

[Hobo,NC]

Lets see if I get this,,, back the tractor up to the post,,, tie chain to bottom of post,,, stand a 4X4 beside the post,,, pull chain up and over the top of the post,,, hook to back of tractor and pull forward... The chain pulls up (to a certain point)...

I had a few this year that did not wanna give up,,, took to men to get it after mess'n with it awhile...

 

[gahorN]

I use a chain on the bottom of my 3-pt carry-all and just raise the carry-all. Pop's 'em right out.