OldDuffus
Member
- Joined
- Jul 22, 2017
- Threads
- 3
- Messages
- 15
I had a problem similar to SHB's or Badboy's with the main drive belt to those two hydrostatic gears (drives) coming off of the pulleys. My mower is a Gravely ZT 24 HP 50" deck and Kohler twin-V engine. I'm just happily zooming around the yard mowing and suddenly the power to the wheels just "goes away" and I'm sitting there with the engine still running but I'm goin' nowhere. Turns out that three of the bolts holding the hydro gear bodies (and, hence, also the big drive wheels) fell out over time and the large drive wheels splayed out looking like those wheels on Matchbox cars. It caused me to panic a little and was disheartening as it appeared like the drive wheels would just peel off of the mower chasis. Two of the bolts were missing at one end of what is called the "weldment, transaxle support" which looks like a structural angle with two rectangular plates capping the ends. A third bolt was missing where one of the transaxle bodies (hydro gears) bolts into the deck of the chasis.
Ironically, this is the configuration you need to purposely create to replace the main drive belt. Indeed, to get the old belt off which, by the way, was severely torn where it fought with the chasis and hydro pulley when the last of those three bolts was lost, this "loosey goosey" condition was needed. To get a new belt on, I had to additionally loosen 4 of the bolts that connect the hydro (transaxle) bodies to the big drive wheel supports. Clearance between transaxle pulley and the chasis was excrutiatingly tight, expecially on the driver's side (left) if the mower were a car. I got the new belt on by dropping the blade PTO belt down off its rear pulley and disconnecting the wiring leading to the electric clutch (that big bulbous thing that hangs under the engine and stops the mower blades from turning). Some say they even remove the clutch to provide more wiggle room when replacing the main drive belt. As it is, I ended up "pinching" the new belt between pulley and chasis on the left (driver's side) by pushing with a slat or stick of wood until the belt popped down and into its V-channel on the pulley.
And the fun did not stop there. I had no assistant to pull back the idler or tension pulley to extend its spring until the new drive belt would engage or slip over it. I used a nylon rope about 3/8 diameter attached to the end of the "swivel arm" that holds the tension pulley to create spring tension. I tied the rope off at the back of the chasis until the belt slipped on at which point I could slowly let the tension pulley ease back to normal tension, creating needed belt tension.
Ironically, this is the configuration you need to purposely create to replace the main drive belt. Indeed, to get the old belt off which, by the way, was severely torn where it fought with the chasis and hydro pulley when the last of those three bolts was lost, this "loosey goosey" condition was needed. To get a new belt on, I had to additionally loosen 4 of the bolts that connect the hydro (transaxle) bodies to the big drive wheel supports. Clearance between transaxle pulley and the chasis was excrutiatingly tight, expecially on the driver's side (left) if the mower were a car. I got the new belt on by dropping the blade PTO belt down off its rear pulley and disconnecting the wiring leading to the electric clutch (that big bulbous thing that hangs under the engine and stops the mower blades from turning). Some say they even remove the clutch to provide more wiggle room when replacing the main drive belt. As it is, I ended up "pinching" the new belt between pulley and chasis on the left (driver's side) by pushing with a slat or stick of wood until the belt popped down and into its V-channel on the pulley.
And the fun did not stop there. I had no assistant to pull back the idler or tension pulley to extend its spring until the new drive belt would engage or slip over it. I used a nylon rope about 3/8 diameter attached to the end of the "swivel arm" that holds the tension pulley to create spring tension. I tied the rope off at the back of the chasis until the belt slipped on at which point I could slowly let the tension pulley ease back to normal tension, creating needed belt tension.