How to Replace the Drive Belts on an Older Murray Riding Lawn Mower
Congratulations! You’re the proud owner of an older Murray riding mower. You can perform repairs with
replacement parts purchased from home improvement stores, local small engine shops or on the Web. Most
Murray manuals can be downloaded free from the manufacturer’s website or from websites that specialize in
manuals such as ManualsOnline. Many Murray mowers were sold under the Craftsman brand, so parts and
manuals may be available from Sears.
Illustrations in this guide are taken from the manual for the Sears 30”, 10 HP riding mower, but can be applied
to Murray mowers of the same type. However, these instructions are NOT intended to be a replacement for
the manual. You should always familiarize yourself with the manual for your machine before attempting any
These mowers have two drive belts: the motion drive belt, which sends power from the motor to a large pulley
called the stack pulley, and the mower drive belt which transfers power to the center blade pulley. Replacing
either belt requires only ordinary tools and usually takes less than an hour.
Things You'll Need
· Open-end wrenches
· Socket wrenches
· Phillips head and slot screw drivers
· Safety glasses
· Owner's manual
· Clean the deck housing of grass and debris, and inspect the condition of the blade while the mower
housing is off.
· Turn off the ignition, remove the key and put it in your pocket before beginning work. Detach the
spark plug wire from the spark plug to further guard against accidentally starting the motor.
Section 1: Replacing the motion drive belt
· Stop the blade by moving the attachment (blade) clutch handle to the disengage position, pointing
towards the mower seat.
· Lower the deck to the middle position - sit on the seat and pull the deck lift lever in towards your legs
then lower the lever.
· Locate the blade drive linkage assembly on top of the mower deck on the opposite side of the deck
from the grass discharge opening. The linkage connects the clutch assembly to the pivot rod and
bracket assembly (attached to the mower deck) by a clevis, a U-shaped fastener secured by a pin
through holes in the ends of the two arms. Pull the cotter key (half-round metal hair pin with one leg
bent into shallow arches) out of the clevis pin and remove the clevis pin. This disconnects the clevis
from the pivot rod and bracket assembly.
· Locate the level adjuster assembly on each side of the mower deck near the rear tires. The level
adjuster plate is a circular, scalloped plate with holes.
· Each plate is attached with a pin through one of the holes to a hanger, a triangular bracket attached to
the deck housing.
· Remove left and right level adjuster pins from the hanger on each side and move the whole mower
housing slightly to the left for the right side or right for the left side until the hanger pin clears the hole
on each adjuster plate.
· Remove the long pin from the front deck hanger.
· Remove the belt from the motion belt stack pulley, which is the large metal pulley above and slightly
to the side of the center (mandrel) blade pulley.
· Remove the mower housing by either sliding the mower deck out from under the mower or by lifting
the front of the mower and rolling it backwards away from the mower deck.
· Push the clutch/brake pedal forward to lock the parking brake.
· Loosen the belt guides at the motion belt stack pulley.
· Pull the motion drive belt off of the idler pulley, which is the small pulley closest to the stack pulley.
· Install the new motion drive belt by sliding it between the stack pulley and the belt guide, and the belt
retainer and idler pulley.
· Position the belt around the motion drive pulley, which is the pulley closest to the left rear tire (facing
the back of the mower.)
· Check the belt to be sure that the “V” side is inside the pulleys and that the belt is inside all the guides.
· Check the belt guides to be sure they are all tight and that nothing is rubbing on the belt..
· Check the clutch/parking brake to make sure it is engaging the belt properly.
· Reinstall the mower housing and check that all pins, bolts and springs are in their proper place.
Section 2: Replacing the mower drive belt
· Engage the clutch/parking brake.
· Disengage the attachment (blade) clutch.
· Lower the mower deck to its lowest position.
· Detach the attachment (blade) clutch clevis from the pivot rod and bracket assembly.
· Move the belt retainer away from the idler pulley.
· Slide the old mower drive belt off of the pulleys and away from the belt guides.
· Cut the belt with metal shears for easier removal.
· Pull the belt guide away from the blade drive (mandrel) pulley.
· Position the new belt on the pulley mandrel pulley with the belt’s “V” side against the pulley groove.
· Pull the belt retainer away from the idler pulley and position the belt in the idler pulley.
· Pull the belt into position between the stack pulley and the belt guide.
· Check the belt for tension. The belt will be slack when not engaged. If it slips out of position inside the
belt guides and pulleys, adjust the attachment (blade) clutch by detaching the clevis from the pivot rod
and bracket assembly and manually turning the clevis to decrease the length of the clutch rod.
· Reattach the clutch assembly and the mower is ready.
· Lawn maintenance
· Small motors
· Equipment repair
· Manuals Online: Murray Mower Instruction Book
· "Craftsman Owner's Manual Model 502.251220 30" Mower/Mulcher", Sears, Roebuck & Co.,
Hoffman Estates, IL 60179. ca 1998.
· Ask an Owner: Murray Riding Mowers [http://www.askanowner.com/qa/view.asp?s=1&qid=169537]
· Murray Mowers: Manuals [http://www.murray.com/na/en/manuals/]
· eReplacement Parts: Murrary Riding Mower Parts Diagram