QUICK AND EASY
Lots of way to skin this cat -- spending time on the front end thoroughly reading prior posts and manual I was able to make quick and easy replacement (less than 1o-15 minutes).
1. Loosen deck deck belt so that it can be removed from PTO pulley by "rolling" belt off the PTO pulley (or spindle pulley). From rear of mower reach underneath with both hands and pull belt with left hand downward and rearward while turning PTO pulley to right. Maintaining downward tension while turning PTO pulley edge belt off the pulley.
2. Remove old transimission drive belt. Typically will already be broken or hopelessly worn so from rear of mower, section with knife and discard.
3. Lower PTO assembly from rear of mower to thread new transmission belt onto engine pulley. NOTE: This is necessary as there is an antirotational bracket that is welded to the framework and prevents the belt from being positioned in place. To lower the PTO assembly you must loosen the 5/8" bolt at the bottom -- to prevent the flywheel from rotating while loosening the bolt remove the spark plug and feed into the spark plug hole a foot or so of 1/4" nylon rope. The piston will come up, hit the rope and lock up the engine. The nylon rope will not hurt the piston or head -- just leave enough out to remove the rope afterwards.
Once the PTO assembly bolt is loosened slowly unscrew only enough so that the PTO assembly drops below the antirotational bracket and the belt can be put into place. Use the notch where the antirotational bracket engages the PTO assembly to facilitate placement of the belt above the engine pulley. Once belt is in place retighten PTO assembly bolt making sure the antirotational bracket is aligned with the notch on the PTO assembly. Remove nylon rope from spark plug hole and replace spark plug.
4. Finish placement of belt.
NOTE: To complete placement of belt you have to remove tension on the transmission idler arm - I'm a "spring puller" so I found it easier to simply detach the spring from the mower frame to release tension on the idler pulley. The manual describes the use of 3/8" drive ratchet being placed in the square hole of the drive idler bracket and used as leverage for releasing tension on idler pulley; while others (see above) have left the spring in place and pulled the idler arm back to remove tension on the belt by threading a wire cable into the square hole in the idler arm and extending the wire to the underside of the framework to the right side of the mower where it could be attached to fulcrum then used to pull back on the idler arm.
Regardless of how tension is taken off the idler arm pulley, from the rear of mower thread belt around the right transimission drive pulley first. and then onto the left transmission drive pulley. The transmission drive belt is then positioned onto the engine pulley at the top of the PTO assembly and then on the drive idler pulley. Tension is then reapplied by reattaching the tension spring (or removing the fulcrum, pull wire and/or ratchet drive).
NOTE: Replacement of the tension spring is "a simple yet a hard to master move" -- thus the appeal of using a wire cable or ratchet drive to unload tension from the spindle arm! Using a pair of vise grips placed right at the base of the spring's hook and oriented so the hook is at 90 degrees to both the hook and the hook's latch on the framework the spring is pulled into position and hooked onto the latch. Adjustment and placement of the vise grips is critical to prevent near misses and frustration. And unless you have the upper torso of a gorilla, position your body so that you are using your legs and not your arms to pull back the spring.
5. Finish by replacing deck drive belt . First place the deck drive belt on all mower blade pulleys and spindle pulleys. Then sitting at rear of mower looking forward reaching underneath grasping the belt with both hands pulling back and sliding the belt back onto the PTO pulley.
In my "spring-pullin'" alternative approach, the tension spring from the movable idler pulley is unhooked, the deck drive belt rethreaded into all pulleys/spindles, and the tension spring replaced into position (again using vise grips and legs to hold and pull).
Tools Needed: Not much -- one foot length of 1/2' nylon rope, vise grips, and large ratchet wrench with 5/8" socket.
Wives do come in handy at times but, she said the last time..you will be hauling it into the shop. Darn, what a strong spring!!!
