gear oil mix

[bcarmalt]

Greetings all
I have a JD Rotary Mower which had not been used for a couple of years. Opened the gear box and the level of gear oil looked a little low. So, in our shed we had some Universal Tractor Fluid which I added (about 1 cup). Then I checked the JD manual and it calls for API-5 gear oil. Looking at the container, I could not find an API rating, but at Tractor Supply I read another UTF that had an API-4 rating.

Will I be doing serious damage to the mower?

Thanks

 

[Wolfy]

1 cup isn't likely to hurt, but a couple of years of sitting should warrant a oil change anyways. My JD mower lists several acceptable gear oils, 80W90 the most common.

 

[bcarmalt]

Thanks Wolfy, I did not think a cup would hurt, but its nice to get a second opinion. Also, I would not have thought about the oil change, but that is a good idea. Another task for the to do list.

 

[bp fick]

Change it out. No harm done. Yeah, put it on your "to do" list.

 

[John Morgan]

I agree 1 cup not going to do any harm. When you change the fluid, damage will occur if you use an "API-4" lubricant. The API GL 4 rating has insuffcient EP additives to properly protect the system from spalling. If your manual calls for a GL-5 rating, be sure to use that.