5025 trans oil

[moe1965 744]

I have a 5025 trans and the manual called for 40 Wt  gear oil.  I'm not having any luck finding it. Should I substitute 80 90 Wt? Thanks in advance 

[pfrederi 17,885]

Wheel Horse specified 40w motor oil in the trannies for awhile.  You can use 80-90w gear oil.  My L-107 has been running on 40w motor oil for 51 year with out a problem

[WHX?? 49,171]

All of mine have 80/90 in it ... no problems.

[Terry M-(Moderator) 2,176]

Even in Minnesota....the 80/90  stuff works fine...

[bottjernat1 2,190]

80/90 all day long! I just drained and replaced  tranny oil in my sisters horse and that is what i used. its working just fine.

[Racinbob 11,232]

They issued a service bulletin 2-3 years after the 2 piece case transmissions came about. They recommended the 40w because of the shift rail suction issue that sometimes caused them to lock in 2 gears. The lighter oil helped that. Once they modified the rails to mechanically help the issue they went back to the heavier gear oil. They just neglected to change the owners manuals back. As a lot of others I use 80w90 but you'd be fine with the 40w if you prefer. 

[953 nut 55,812]

              I have been using 40 W oil in a couple of mine for a couple of decades but use the 90 W in most with no issues. I think the 90 W gear oil clings to bearings better than motor oil so it is the better choice.

[moe1965 744]

I guess my next question would be is there a difference between 40 Wt gear oil and 40Wt moter oil. 

[pfrederi 17,885]

10 minutes ago, moe1965 said:

I guess my next question would be is there a difference between 40 Wt gear oil and 40Wt moter oil. 

Maybe so..But when WH specified 40w it was motor oil...don't think they had 40w gear oil 50 years ago.

[oliver2-44 9,870]

There are several different classification scales that oils are rated on.

As you can see in the chart below a 40 wt motor oil (SAE Grades Crankcase oils) is equal in Viscosity to 90 wt (SAE Grades Gear Oils) A #4 or #5 AGMA grade gear oil is the same, and a 150-220 ISO VG gear oil is also the same.  Is that confusing enough!

 

[Skipper 1,788]

I would also recommend the thicker gear oil, just because it is a better oil for the application, but, and that's a big but: 

 

Had it been a hydro, the high torque part of it had been about the same, and soaked in 5-30W or the like, or even thin ATF oil,  with no problem what so ever...........................

 

Point being, as long as you have good fresh oil on it, and plenty of it, instead of watery sludge, you are not in a bad way.

 

No matter how you twist and turn it, those trannys almost newer see any kind of heavy strain on the internals, in the category that modern oils are made to handle. But I also like to be more safe than sorry, so I go for the strongest oil for the application, even if it is serious overkill  

 

Edited January 5, 2019 by Skipper

[moe1965 744]

Thanks everyone for your input. I flushed out the trans today with diesel fuel and got out all the crud I could and put 80 90 Wt in because that's what I had a lot of laying around. Drove the tractor around for the first time today.