Hi, just joined forum looking for advise. I’m an experienced auto tech I do auto trans and all but as far as mowers never done anything with a hydrostatic trans. Recently purchased a used Troy bilt zero turn and the RH transaxle keeps blowing out the seal on the brake gear shaft. I’ve replaced the seal and topped/purged fluid and it just pushes the seal right out of the casing after a few passes cutting. It’s a oem seal I checked to verify correct size. Wondering if a venting issue is causing this blowout or if another seal is internally bypassing fluid to the wrong port and pressing the seal out. Any help would be appreciated. I’ve attached pictures of the model number and pictures showing the LH seal pushed out compared to the LH. Thanks??
I would be checking the vent hose on top of the unit for blockage. Sounds like pressure buildup when the oil warms up. Some just have a short hose with a umbrella type valve on top others have a hose that goes to a small oil tank
#3
StarTech
Which one of the two seals did you use? Also did you purchase the seal kit 70853?
SEAL, LIP .625 X 1.000 X .250
SEAL, LIP .50 X .88 X .25
70853 is the seal kit I got. Had to call manufacture to get it and verify it was correct. It is the only seal in the package anywhere near fitting the shaft and failed the same way the last seal did. And as far as the valve I made sure to clean it when I replaced the seal. Shop air can go thru it one way only (air can go into unit but not out. I believe to prevent fluid from puking out) and after seal blew out I did push it back in and topped fluid and swapped the vent caps from left to right and mowed a while longer and LH was fine RH failed again
#5
StarTech
When you said you top the fluid off you didn't overfill the unit did you?
Could have been overfilled I didn’t see a check plug anywhere and left the vent plug off while purging. And as soon as it starts leaking it looses power until topped off and purged again
