Low oil in the transaxle could cause over-heating and loss of drive. That model has a Hydro-Gear 310-0650 transaxle which takes 20W50 motor oil. Using other oil could cause drive problems or transaxle damage so be sure to use the correct oil only.
The transaxle will hold approximately 2.5 quarts or 80 ounces of oil but the level should be verified by measuring down from the top of the housing where the fill plug goes in. The oil level should be 1.25 â€“ 1.5â€ down from the top of the housing.
Take care and try the unit in an open area after adding oil as any air in the fresh oil could make the engagement more abrupt or inconsistent than normal. If you are changing the oil altogether, the oil is drained by removing the breather assembly or vent cap, see
reference key 113 and 114
in the image
It is recommended you recheck the level after a short time of running, and after using forward and reverse a few times, as any air will purge out of the fresh oil and the transaxle then might require more oil be added.
Many times issues with loss of drive are actually due to a problem with the drive belt slipping and not the transaxle itself. So if adding fluid does not resolve the issue be sure that your drive belt is not worn or showing any polished areas that indicate slipping and be sure the belt is routed correctly and all the tensioners work properly.
If the oil level is up and the belt and input pulleys are okay and not slipping, or you are hearing any abnormal noises from the transmission then the problem might be internal. A new transaxle is part number 150071 and there may be a rebuilt one available for slightly less under the part number 150071R.