Can you mix 85w 140 and 90w 140 in final drive?

[BA Deere]

They don`t make that 90w 140 anymore outside of Saudi Arabia.  i have a old oat combine I`m sure 90w 140 is in the final drive, but can a guy top it off with 85w 140? They say some of the new gear oils have sulfer that`s hard on brass bushings.  Or should a guy drain the old and put in the new 85w 140 and not worry about it?  Or am I being Sheldon Cooper about this?  🙂

[bikinkawboy]

Traditionally gear lubes have always used sulfur to add shear properties.  That's why they stink.  Modern engine oils have very little zinc these days, which also provided shear properties. 

That is one reason why modern engines all use roller tappets to eliminate the shearing action of the cam lobe on the lifter.  In my old double overhead cam motorcycles I use engine oils

meant for older diesel tractors, which (at least used to) has higher levels of zinc or other shear additives.  Those old bikes have super stiff valve springs and plenty of shearing action

between the cam and lifter.  Haven't had any any problems yet.    

[r3020]

I would drain it. Probably doesn't hold that much anyway. My bigger concern would be why is it low? Can you see where it leaks out? Seal bad because of a bearing going out?

[BA Deere]

Hey 3020, the pumpkin isn`t low, it`s just when you check it I wonder what grease to use if it needed any.  With slow travel of a combine and low hour use in all reality as long as it`s "something" in there, it`d probably outlast the rest of the combine.   The book says use 90w 140 but I don`t know where you`d get that.  Just reading labels, I would guess just straight 140 weight oil work good.  But if it just needed a 1/2 cup or something, I reckon put in 85w 140 Lucas, I think that`d mix with anything.

[farmer46]

You can do a lot different things, several years ago my reverser box on 7720 started to leak, with 200 acres to go, I just filled up gear box with john deere corn head grease, maybe 4 tubes, and kept on.  Had no problems and replaced seals and bearing in the winter season. 

[r3020]

I would say farmer 48 is right. Since you aren't talking a lot of acres through her. BTW, what number does she wear? And you still raise oats? I'm guessing you need it for sow feed. I have thought of raising some again for all of them little Holstein calves we start. The thought usually exits my head pretty quickly though.

[BA Deere]

It`s a 4400.  Yes raising oats around here isn`t common, but not unheard of, sugar plums and $7 corn still dancing in many heads  🙂  I wouldn`t raise it to sell, the straw you can`t give away and to sell they dock if it`s under 38lb.  i wouldn`t let it get out that a guy has a oat pickup or you`ll get calls 50 miles away to do custom 5 acre jobs for $25/a....noooooo thank you  🙂

[dmowitz]

When in doubt, ask your John  Deere dealer. They certainly will have a replacement grease to suit your combine's need.

[r3020]

As an added benefit it will put a big dent in your tax bill.

[siloguy]

I have mixed the two and never had an issue. I have used 85-140 to top off boxes with 90W and that was OK.