Tufftorq transaxle k66y

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May 29, 2009
On. Can.
I have a Craftsman gt5oo garden tractor
with a k66y transaxle.
Im getting near the 50 hour mark and want to change the axle oil.
There is a small plastic bottle on top of the axle with a bit of oil in it.
Do I have to remove this bottle or can I just add oil through it to the trans axle?
There is also another place to add oil to the transaxle.
Do I have to add oil to both places.
Does anyone know how much oil it takes. I do know how to drain the trans axle.

I know nothing of that, but I do know that tuff torq has great customer service and will reply quickly to an email.

In my lawn tractor the TT had to be removed to drain it. We used M1 15w-50 and the unit is much quieter and very happy...
Yes, it's probably easiest to remove the transaxle from the tractor to drain and fill it.

The plastic bottle on top is the overflow, similar to a car's radiator overflow tank. On yours, you should fill the transaxle and then you need to purge the air out of it and then top off via the plastic tank on top until you reach the proper level.
You may not need to drop the transaxle. I recently changed the oil in a K61 installed in a relatively old Toro/Wheelhorse. Drain plug? Check. Oil reservoir (plastic bottle) under the hood with a hose to the top of the transaxle? Check. Drained the oil, but there was no way the oil in the reservoir would voluntarily flow into the transaxle through the long hose to refill. Rather than dropping the transaxle, I removed the sheet steel panel holding the seat and covering the gas tank, lifted the tank out of the way, and accessed a second fill plug on top of the transaxle. I could also have pulled the hose, if desired, and used that as a refill point. All in all some work, but probably easier than dropping the transaxle because there was no need to pull any linkages, belts, etc. If you can access the reservoir and it sits directly above the transaxle, it'll probably work okay as a refill point.

Accessing the transaxle from the top also gave sufficient room to clean all the debris accumulated over the years.
Mine took right around 3 quarts. There are two places to fill the transmission, and you have to fill both. That plastic bottle is like an overflow bottle for fluid expansion. Just pouring it in there won't be much help to refill the transmission.

The transmission mounts to the machine with only 4 bolts and a few linkages. It was much easier to drain and refill it with it removed from the machine. I used Castrol Synthetic 5w50.

I believe both fluid reservoirs in the transmission need to be filled to 1" from the top, and the plastic bottle is supposed to be 1/2 to 3/4 full.
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