Scotts S1642 Hydrostatic Transmission

[kennethrbest]

Is there a maintenance schedule for the transmission? I've had the same mower for over 20 years and if there's fluid in the transmission, I'm thinking it could be due for a fresh refill. Also, exactly how would I drain and refill the fluid(s).
Also, has anyone discovered a way to replace the transmission pulley without dropping the trans.

 

[StarTech]

Could always remove the fender pan but it is a lot easier to pull the transaxle. Beside the pulley and fan comes off as one piece and then you can separate the two,

And in order the change the oil in the K51 you would still need to remove transaxle. Invert it to drain, split the case in order to replace the filter. Use 15W50 Synthetic oil
And I would recommend replacing all the seals while you are changing the oil since the unit is over 20 yrs old.

 

[Tiger Small Engine]

Could always remove the fender pan but it is a lot easier to pull the transaxle. Beside the pulley and fan comes off as one piece and then you can separate the two,

And in order the change the oil in the K51 you would still need to remove transaxle. Invert it to drain, split the case in order to replace the filter. Use 15W50 Synthetic oil
And I would recommend replacing all the seals while you are changing the oil since the unit is over 20 yrs old.

So in other words, this is why the oil and filter rarely/never get changed in hydrostatic transaxles. Plan B is to pump out as much oil as possible and refill.