Is too much transmission fluid harmful?

From what I have read, no it is not harmful, I am surprised you could put that much in it. If you are still uncertain, contact your John Deere dealer and ask your question. They could best advise you so you don't violate your warranty, if you still have one.

I would contact John Deere to be sure.

Hello you might wish to contact John Deere. We called them about installing a new belt and they were very helpful. I hope you find an answer.

https://www.deere.com/en/our-company/contact-us/

Hi E.C.P., From what I've read having too much transmission fluid can cause the sals to leak and become damaged. Why not siphon the extra oil out right away rather than risking any damage to your lawn tractor or spilling the transmission fluid on your lawn? Here's a video of a product used to siphon out oil of any kind.

https://www.youtube.com/watch?v=v8ZyEFdCidA

John Deere contact info:

https://www.deere.com/en/our-company/contact-us/

1/2 quart shouldn't be much of a problem. If you are concerned just drain it off. Calling JD to see what they recommend is a good idea,

I like the turkey baster idea that Betsy suggested - just to be on the safe side!

It will come out the excess

It should not be much of a problem, but to be on the safe side I would go to the Dollar Store, buy a turkey baster and take some fluid out.

Just go ahead and run it, if there is too much in there, the excess will come out of the overflow. 1/2 quart really isn't much

Hello, hope this helps you,

Overfilling the transmission can adversely affect the performance of your transmission. However, if you overfill it with like 1/2″ or 1/4″ quartz there is no need for action. If you overfill your transmission with 1 quart or more, you should consider draining it.