MTD
Gas Walk-Behind Mower

Model # 12A-44MC055 Official MTD lawn mower

Here are the diagrams and repair parts for Official MTD 12A-44MC055 lawn mower, as well as links to manuals and error code tables, if available.

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Model diagram and schematic

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ALL PARTS
Showing 10 of 71 parts  |

Blade-21" Mu 742-0741
#24

Mower parts diagram

Blade-21" mu

Part #742-0741

Replaced by #942-0741A

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Manufacturer substitution
This part replaces 742-0741. Substitute parts can look different from the original.
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$27.71
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Lawn Tractor Flange Nut (replaces 00012173, Wd-129-103) 712-04065
#43

Mower parts diagram

Lawn tractor flange nut (replaces 00012173, wd-129-103)

Part #712-04065

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$3.39
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Lawn & Garden Equipment Nut 712-04064
#21

Mower parts diagram

Lawn & garden equipment nut

Part #712-04064

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Knob 720-04072
#9

Mower parts diagram

Knob

Part #720-04072

Replaced by #720-04072A

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Manufacturer substitution
This part replaces 720-04072. Substitute parts can look different from the original.
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Lawn Mower Blade Support (replaces 936-0524a) 736-0524B
#27

Mower parts diagram

Lawn mower blade support (replaces 936-0524a)

Part #736-0524B

Replaced by #736-0524B-1

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Manufacturer substitution
This part replaces 736-0524B. Substitute parts can look different from the original.
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Wing Nut 712-0397
#38

Mower parts diagram

Wing nut

Part #712-0397

Replaced by #712-0397A

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Manufacturer substitution
This part replaces 712-0397. Substitute parts can look different from the original.
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V-belt 754-0637A
#51

Mower parts diagram

V-belt

Part #754-0637A

Replaced by #954-0637A

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Manufacturer substitution
This part replaces 754-0637A. Substitute parts can look different from the original.
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Lawn & Garden Equipment Hex Bolt (replaces 01000943, 910-1257) 710-1257
#25

Mower parts diagram

Lawn & garden equipment hex bolt (replaces 01000943, 910-1257)

Part #710-1257

This item is not returnable
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Cable Tie 726-0240
#11

Mower parts diagram

Cable tie

Part #726-0240

Replaced by #726-0178

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Manufacturer substitution
This part replaces 726-0240. Substitute parts can look different from the original.
This item is not returnable
In Stock
Grass Bag Frame 747-04080
#3

Mower parts diagram

Grass bag frame

Part #747-04080

Replaced by #747-04080A

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Manufacturer substitution
This part replaces 747-04080. Substitute parts can look different from the original.
$65.07
13% OFF MSRP : $75.00
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Symptoms for gas walk-behind mowers

Choose a symptom to see related walk-behind mower repairs.

Main causes: engine needs tune up, dirty or clogged carburetor, damaged flywheel key…

Main causes: uneven wheel height settings, damaged wheel, dull or damaged cutting blade…

Main causes: damaged cutting blade, loose cutting blade, damaged flywheel key, engine needs tune up…

Main causes: stale gas, engine needs tune up, bad spark plug, dead battery, bad recoil starter, faulty safety switch, ba…

Main causes: dirty carburetor, bad spark plug, clogged air filter, engine choke problems, clogged gas cap vent…

Main causes: drive control cable failure, worn or broken drive belt, bad transmission, broken drive wheel…

Repair guides for gas walk-behind mowers

These step-by-step repair guides will help you safely fix what’s broken on your walk-behind lawn mower.

How to replace a lawn mower spark plug

How to replace a lawn mower spark plug

Take a few minutes to replace the spark plug during your lawn mower's annual tune-up or if the spark plug is burnt or cr…

Repair difficulty
Time required
 15 minutes or less
How to replace a lawn mower blade

How to replace a lawn mower blade

Check your lawn mower blade regularly and replaced it if it's bent or damaged. …

Repair difficulty
Time required
 15 minutes or less
How to replace a lawn mower flywheel key on a flathead engine

How to replace a lawn mower flywheel key on a flathead engine

When you hit a hard object with your mower, the flywheel can shear to protect more expensive components. Learn how to re…

Repair difficulty
Time required
 45 minutes or less

Effective articles & videos to help repair your walk-behind mowers

Use the advice and tips in these articles and videos to get the most out of your walk-behind lawn mower.

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Introducing new technical repair content that we’re developing for the Sears Technical Institute

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