How to Replace a Lawn Mower Drive Belt on a Riding Mower
These instructions specifically are for a 700 Series riding mower. Depending on your model, the steps to install mower belts may vary. If you are uncomfortable with this procedure or don't feel qualified to replace mower belts, please contact your Authorized Service Dealer for drive belt replacement.
Always observe safety rules when performing any maintenance. Safety glasses or goggles, and hand protection, in the form of mechanic gloves, should always be used.
Before starting this project, make sure you have the correct drive belts. You can use our Parts Look-Up Tool to find your belt part numbers for your model of riding lawn mower. The V belt found on your tractor is specially designed to engage and disengage safely. A substitute (NON OEM) V-belt can be dangerous by not disengaging completely. For a proper working machine, always use factory approved lawn mower belts.
It is recommended that you take a picture of how the lawn mower belts are routed before removal. During the installation process, you can refer back to the pictures for reference.
Note: Because there is inter-play between the two drive belts in the variable-speed pulley system, it is a good practice to replace both drive belts at the same time.
Step 1: Position the mower to change the lawn mower belt
Place the mower on a flat, level surface.
Step 2: Set the parking brake
Set the parking brake to ensure the mower won't start rolling while you're working.
Step 3: Be sure the engine is cool before you replace the mower belt
If the engine is hot, allow the exhaust system to cool down before attempting any maintenance.
Step 4: Detach the spark plug wire
Open the hood and remove the spark plug wire(s). Ground the spark plug wire (s) against the engine to prevent unintended starting before removing the riding lawn mower belts .
Step 5: Remove the cutting deck
Remove the cutting deck. Instructions for removing the cutting deck can be found in your Operator's Manual in the "Service" section.
Step 6: Remove the battery
Lift the seat to gain access to the battery. Remove the battery. Note: When disconnecting the battery, always disconnect the black negative battery cable first, then disconnect the red positive battery cable.
Step 7: Loosen the transaxle pulley
Look down through where the battery was located. You will see a large transaxle pulley. Loosen the large nut holding the transaxle pulley to the input shaft of the transaxle using a 7/16" socket.
Step 8: Relieve tension on the upper drive belt
Disconnect the spring from the anchor bolt on the left side of the tractor using a spring puller or a small piece of rope. This will relieve tension on the upper drive belt. Note: Orientation of left and right is determined from the operator's position in the seat.
Step 9: Remove the upper drive belt
Maneuver the upper (rear) belt from the transaxle pulley, and remove the belt from the mower.
Step 10: Remove the lawn mower belt guide
Remove the belt guide from the variable speed pulley bracket using a 1/4" socket. Note: This is accessed through the battery compartment.
Step 11: Take the belt off the variable speed pulley
Lift the middle sheave slightly so the belt will clear the belt guide, and slip the belt off of the variable speed pulley.
Step 12: Remove the belt keeper
Remove the belt keeper surrounding the engine pulley using a 1/2" wrench.
Step 13: Remove the bolt securing the crankshaft pulley
Remove the bolt securing the crank shaft pulley using a 5/8" socket. Note: The use of an air impact gun is recommended for removal purposes. If not, use a strap wrench to hold the crankshaft pulley while loosening the bolt.
Step 14: Make a note of where parts are located before you install a new mower belt
When removing the engine pulley, take note of the orientation of the parts for reassembly (or take a picture). The pulley is secured by a bolt, lock washer, and a heavy flat washer. A spacer is positioned above the pulley on the crankshaft. The top edge radius matches the step on the crankshaft.
Step 15: Remove the lower drive belt from the lawn mower
Remove the lower drive belt from the mower by pulling it towards the engine.
Step 16: Install the new lower drive belt
Belt installation is basically the reversal of the removal process. Install the new lower drive belt . Confirm the correct belt routing inside of all the belt keepers and through all the guide pins. Refer to your pictures taken before the lawn mower belt removal.
Step 17: Apply anti-seize compound to the crankshaft
Apply a very small quantity of anti-seize compound to the engine crankshaft. This will help ease the crankshaft removal in the future when needed. Note: DO NOT get any anti-seize compound on the bolt threads or in the bolt hole of the crankshaft.
Step 18: Insert a spacer
Install the spacer with the rounded shoulder towards the engine.
Step 19: Install the crankshaft pulley
While holding the spacer in place, install the crankshaft pulley. Be careful not to get any of the anti-seize compound on the belt or in the "V" of the pulley.
Step 20: Manually install the crankshaft pulley bolt
Install the crankshaft pulley bolt with the lock washer and heavy flat washer in place, the lock washer to the bolt head and the heavy flat washer to the crankshaft pulley.
Step 21: Tighten the crankshaft pulley bolt
Using a torque wrench and tighten the crankshaft pulley bolt, to a torque of 37.5 - 50 foot pounds (51-68 Newton Meters).
Step 22: Replace the lower transmission belt
Place the lower transmission belt into the upper "V" Pulley closest to the engine on the crankshaft pulley.
Step 23: Slide the belt back onto the variable speed pulley
Lift the middle sheave slightly so the belt will clear the belt guide and slip the belt onto the variable speed pulley. Make sure the belt is fully seated in the belt grooves.
Step 24: Re-install the lawn mower belt keeper
Re-install the belt keeper surrounding the engine pulley, using a 1/2" wrench.
Step 25: Re-install the belt guide
Re-install the belt guide removed from the variable speed pulley bracket using a 1/4" socket.
Step 26: Install the new upper drive belt
Install the new upper drive belt into the upper sheave of the variable speed pulley and around the transaxle pulley. Make sure the belt is fully seated in the belt grooves.
Step 27: Re-install the tension spring
Re-install the tension spring removed at the beginning using a spring puller or a small piece of rope and connect it to the anchor bolt on the left side of the tractor.
Step 28: Secure the transaxle pulley
Tighten the large nut that secures the transaxle pulley to the input shaft of the transaxle. Use a torque wrench and torque to 10-15 foot pounds (13.6-20.3 Newton meters).
Because of the tension change when you replace mower belts, it is always recommended to check all drive adjustments after changing the drive belts.
The following procedure will be for the speed control linkage on the variable speed belt drive.
Step 29: Remove the cotter pin from the ferrule on the variable speed pulley bracket
With the parking brake still engaged remove the cotter pin from the ferrule on the top side of the variable speed pulley bracket.
Step 30: Disconnect the ferrule
Disconnect the ferrule from the bracket. Note: If an adjustment is needed, there will be tension on the linkage, and the resulting friction will create resistance when sliding the ferrule out.
Step 31: Thread the ferruel up or down the rod as necessary
Thread the ferrule up or down the rod so that the post fits into the hole without any resistance.
Step 32: Reinstall the cotter pin
Reinstall the cotter pin back through the hole in the ferrule on the top side of the variable speed pulley bracket.
The next procedure will be for the cruise control/parking brake adjustment on the variable speed belt drive.
Step 33: Remove the cotter pin that affixes the ferrule to the latch assembly
With the parking brake still engaged, remove the cotter pin that secures the ferrule in the latch assembly. Next, disconnect the linkage from the latch assembly.
Step 34: Adjust the ferrule with a new cotter pin
Thread the ferrule up or down the rod so that the post of the ferrule fits into the hole with out any resistance.
Step 35: Secure the ferrule with a new cotter pin
Secure the ferrule to the linkage using a new cotter pin and test the operation of the linkage.
Step 36: Re-install the cutting deck
Install the cutting deck back in place under the mower. Refer to your Operator's Manual in the "Service" section. Follow the cutting deck removal instructions in reverse order.
Step 37: Re-install the battery
Install the battery. Connect the red positive battery cable to the positive battery terminal first. Next, connect the black negative battery cable to the negative battery terminal.
Step 38: Reattach the spark plug wire(s)
Reconnect the spark plug wires to the spark plugs.
Step 39: Check the operation of the new lawn mower belts
Start the unit and check that all linkage and related safety features are operating correctly before returning the mower to service.