I rebuilt the mower deck on my GT3000 this past spring. At that time, while I had the deck off the tractor I jacked it up to see about replacing what I call the Primary Drive Belt. This belt comes off the engine's crankshaft pulley, goes aft to the hydro trans and picks up a drive pulley and idler on the mower deck. The three deck blades are connected together by a second belt.
With the deck off, after removing the belt guides (guards?) and disconnecting the idler spring, I discovered that I did not have enough slack to remove the belt so I gave up, thinking that this is a job for the winter when I'll pull the seat, rear fender assy, fuel tank, and have at the belt with much more access. The belt was obviously worn, but I'd hoped to get the summer mowing season out of the way before I dived into this task. Summer is over and I'll be diving into this once the snow falls.
Has anyone here replaced this belt? Is it possible to do so without removing the engine pulley? What is (are) the secret(s) to doing this? The Sears Manual that came with the mower simply says to create slack by removing the drive belt tension spring, then "remove belt from all idler pulleys, transaxle pulley and then from the engine pulley". No way does this give enough slack, especially since the belt has to go over the fan atop the hydro.
I found some instructions - maybe here or maybe online that were in my files. Without going under the tractor I don't know if these are specific to my tractor. My original manual simply says what I quoted above. The instructions from my computer file are attached below.
Note: When I pull the tank, I'll also have access to the hydro transaxle and I'll replace the hydro juice, too. There is a method to my madness.
Sears GT 3000 Drive Belt Replacement
Remove Mower Deck
Remove the ground drive belt
Remove the flywheel screen cap and position a socket wrench on the flywheel bolt with the wrench handle resting against the fuel tank to keep the crankshaft from turning when you remove the engine pulley bolt.
Remove the engine pulley bolt and washer and then pull the engine pulley off the crankshaft.
Release the drive belt from the pulley.
Release the belt from the idler pulleys and belt guides.
Lift the seat remove the bolt connecting the negative cable to the battery.
Lift the insulating cover and remove the bolt connecting the positive cable to the battery.
Lift the battery out of the battery box.
Release the seat switch wire harness clip from the seat bracket to create slack in the harness.
Release retaining tabs and lift the battery box out of the tractor body.
Set the box on the fender.
Release the drive belt from the transaxle pulley.
Pull out the ground drive belt.
Tip: You can also keep the crankshaft from turning as you remove the engine pulley bolt by removing the spark plug and then stuffing nylon rope into the engine cylinder.
Tip: If the old belt is still intact, take a photo of how the belt routes through the idler pulleys so you can route the new belt correctly. If the belt is broken, see the owner's manual for belt routing.
Tip: Spray a rusted crankshaft bolt with penetrating oil so you can remove it easier.
Install the new ground drive belt
Loop the ground drive belt over the transaxle pulley.
Position the battery box in the opening and align the wire harness and battery cables.
Lower the battery box into the tractor body and engage the retaining tabs.
Connect the seat switch wire harness clip to the seat bracket.
With the insulating cover positioned on the cable, connect the positive battery cable to the positive battery terminal.
Connect the negative battery cable to the negative battery terminal.
Lower the seat.
Route the belt through the chassis and over the steering plate.
Push the belt through the inside of the front belt guides.
Loop the belt over the engine pulley, line up the pulley notch with the crankshaft groove and slide the engine pulley onto the crankshaft.
Position the wrench on the flywheel bolt so the wrench handle rests against the fuel tank to prevent crankshaft rotation as you reinstall the engine pulley bolt.
Install the engine pulley bolt and washer.
Remove the wrench from the flywheel bolt and reinstall the flywheel screen cap.
Using your photo as a guide, route the right side of the belt through the front and middle idler pulleys.
Slide the left side of the belt into the belt keeper and over the rear pulley.
Remove the rope from the engine cylinder and reinstall the spark plug.
