Small Engines (Lawn Mowers, etc.)/Transmission
QUESTION: Hello - I have an older Simplicity 6516 tractor with a hydro transmission. Over the past month it is going slower and slower up the small incline in my yard. Engine rpm's remain the same but tractor slows way down. Drive belt from engine to trans was replaced in August. Is my transmission going bad? Many thanks -
ANSWER: Hi Bill
can you give me model and make of hydro transmission unit , there should be a tag or sticker on it - but if all inputs are good and no drag or brake bind etc , sounds like it may be either very low on oil ( possibly cavitating) or the pump and or hydraulic motor in the hydro have worn out hence the slow speed
let me know make and model of hydro unit please
---------- FOLLOW-UP ----------
QUESTION: OK. Simplicity 1691263. Transaxle group. Fluid is full but has not been changed recently. Do not see exact make and model of hydro trans unit. Here is a diagram: http://www.partstree.com/parts/?lc=simplicity&mn=1691263+-+6516H%2C+16HP+Hydro&d
I would try changing oil and filter on the unit 1st , then provided all inputs from vee belt, pulley etc are ok and unit has correct fluid and quantity but is still not moving properly it may well be the hydro pump / motor unit inside the transmission
be sure trans belt has good tension it and brake system is not dragging/binding
be sure the link from foot or hand control lever to hydro unit is moving the pump swash plate that goes into the transmission from the side ?
if all is good , then only be the transmission playing up !!!
see what you can find , let me know
update ----has the oil and oil filter been replaced, and unit purged of any air ?incase its dropped its additive pack.
have you checked nothing is restricting flow of oil from oil tank to pump ie blocked / restricted tank screen ?
note be sure that the bypass is not partialy disengaged or is stuck open
its possible releif valve may be stuck open or sticking
these units have a eaton cam ring type pump on the top side of trans , and a l/h and r/h eaton wheel motor / with differential gear assy
low flow of oil through system maybe causing low speed even though input shaft speed is good to pump , in hydraulic terms flow of oil relates to speed and the pressure relates to torque both are quite closely related
as stated earlier simple things 1st then if still not responding , decision weather or not to relief valve ,eaton pump , wheel motors.
let me know if anything helps