Barely have 56 hours on new zt60 hd Gravely mower and tall grass broke the hydro drive belt . do I have to remove the clutch to replace the drive belt ? Looks that way to me but thought I'd ask first before I did all that .
I don't think so. You should not have to remove the clutch in my opinion, although it makes it easier to get to things, but not critical.
Some say to remove the electric clutch, that fat thing "blob" that stops the blades quickly for safety. You should only have to loosen and drop down the PTO (blade belt) from the bottom pulley and let it sag, having loosened the spring on the mower deck. You would also need to disconnect the wire that connects to the electric clutch so that the ground drive belt can clear it. During my clarification added below, I discovered that the bracket that slides into a slot on the electric clutch body must also be removed to pass the installation belt upward to the upper pulley. This bracket or bar supports the left one of those push-pull bars that places the mower in free-wheel or back to driven. I left the bracket hang and dangle from the push-pull rod only to have it fall and conk me on the head while loosening framing bolts under the unit.
I mentioned in another post that I tied a thin rope to the idler pulley arm hole where the spring attaches and extended the spring by threading the rope to the rear, left corner of the frame, pulling very tight so that the idler pulley leaves the belt really loose and tying the rope to the rear, left corner of the frame, back around the engine's left side. You may have to remove the rope while slipping the belt off the pulleys and through the back side of the mower frame and re-tension it when the belt has cleared.
The belt must clear the hydrostatic transaxle pulleys (they have fans on them) and slip off upwards and the belt extricated through the rear of the machine. The belt can't slip downward because it will be hung up in the transaxle bodies, those two aluminum castings into which the drive wheel axles feed. The belt will not slip upwards easily because the frame is too close to the transaxle pulleys on the outboard sides. I had to loosen the three large bolts and nuts on both transmissions so that they sag and rotate so that the pulleys pull away, toward the inboard, from the sides of the frame to provide clearance to safely slide the ground drive belt past. Keep the (4) bolts tight, (8) total, that attach the wheels to the axle housing. On each side of the mower, only loosen the two bolts (4) total that tie into a trough-shaped angle with flat plates welded to the end, called the "weldment". Loosen the one (2) total, longer, thinner vertical bolt and nut that fastens to a right-angle bracket attached to the frame at the top of the transaxle body. You'll see a "frightening" sagging with the tires rotating outboard on the floor like a bow-legged cowboy. It will look like those dune buggies where the wheels' tops lean toward the car. But this also rotates the pulleys with those fans so that they move away from the frame to let the belt pass. Of course, all of these are re-tightened after the new belt is on and finally, reattach the wires to the electric clutch and the blade PTO belt goes on its lower pulley as a last step.
For any following this thread, I want to add a clarification or helpful point. I recently installed a new drive belt to replace the one that got nearly severed last mowing season when several bolts were lost from the under carriage support bracing, allowing the wheels to sag and twist alarmingly. I was able to leave the electric clutch in place, but I had to disconnect it from the wiring harness leading to the electrical feed from the battery via that red button you pull or push to activate the PTO mower blades. Topologically, you must temporarily remove the blade PTO belt (lower belt) from its pulley so that the replacement belt for the hydrostatic transaxles can be "threaded" up and around the electric clutch "blob" with the wiring harness disconnected to allow the belt to pass upward to sit on the upper pulley on the motor axle. You must also loosen and swing out of the way the bar that keeps the electric clutch from rotating. The "painful", difficult part was threading the belt around those pulleys that have the fan blades under them. Again, topologically, the forward new belt end or loop must be slipped DOWN over those pulleys which are too close to the chassis sides. Removing bracing bolts as I describe above begins to move the pulleys inboard to provide belt clearance but it still has to be pinched through a disgusting, tight clearance with chassis. I ended up getting the belt in position to traverse the small gap and had to place a short piece of 2x4 on top of the transaxle pulley and use a flat roofing crowbar to "coax" the pulley downward by levering on the bottom of the chassis frame member. Then I took a stick with my free arm to force the belt through the gap, repeat with the other pulley.
The final step is to somehow get the back side of the v-belt surface around the spring-loaded idler pulley. I tried looping a rope through the hole in the idler arm that the spring attaches to and pulling the rope and idler spring toward the rear of the mower, wrapping the rope around the chassis at the rear. But it was not enough to get the belt around the idler pulley. I ended up taking a long 2x2 piercing the unit from the top which could only be done if I moved the bar/angles holding the seat springs up, to the side and opening the top of the unit up. To do that, I had to temporarily disconnect the fuel hose, ground wire lead to the engine and loosen the throttle and choke cables by disconnecting them where they attach at the back of the engine so that the seat angle could rotate up and to the right side of the ZT mower. The bottom of the 2x2 stick pushed against the wide roller on the mower deck, pushed in the opposite direction to force the idler pulley toward the rear and pivoted against something between those two points creating a fulcrum. It was a balancing act and excruciating to assure that I had the belt siting in ALL the pulley v-grooves. At my age (67 in June of 2020) this took the most part of a day to accomplish.
