MTD
Gas Walk-Behind Mower

Model # 12AE76JU099 Official MTD lawn mower

Here are the diagrams and repair parts for Official MTD 12AE76JU099 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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Showing 10 of 239 parts  |

Brake Pad 799021A
#38

Transaxle breakdown diagram

Brake pad

Part #799021A

Replaced by #799021

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Manufacturer substitution
This part replaces 799021A. Substitute parts can look different from the original.
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Lawn & Garden Equipment Hex Flange Nut (replaces 753-05549, 912-0417a) 712-0417A
#50

Engien/transmission/deck diagram

Lawn & garden equipment hex flange nut (replaces 753-05549, 912-0417a)

Part #712-0417A

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$8.00
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Lawn Tractor Ignition Key (replaces 504-00621, 625-04124, 625-05000, 625-05002, 725-05228, 925-1745, 925-2054a) 925-1745A
#75

Handle/frame/fuel tank/wheels diagram

Lawn tractor ignition key (replaces 504-00621, 625-04124, 625-05000, 625-05002, 725-05228, 925-1745, 925-2054a)

Part #925-1745A

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Yard Machines Lawn & Garden Equipment Nut 712-04064
Yard machines lawn & garden equipment nut

Part #712-04064

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This item is not returnable
$4.49
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Toro Lawn & Garden Equipment Carriage Bolt (replaces 753-08024, 910-0451) 710-0451
#44

Engien/transmission/deck diagram

Toro lawn & garden equipment carriage bolt (replaces 753-08024, 910-0451)

Part #710-0451

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$5.42
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Yard Machines Lawn Tractor Flange Nut (replaces 00012173, Wd-129-103) 712-04065
Yard machines lawn tractor flange nut (replaces 00012173, wd-129-103)

Part #712-04065

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Lawn Mower Idler Pulley 756-04129B
#31

Engien/transmission/deck diagram

Lawn mower idler pulley

Part #756-04129B

Replaced by #753-08171

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Manufacturer substitution
This part replaces 756-04129B. Substitute parts can look different from the original.
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Plate 790007
#37

Transaxle breakdown diagram

Plate

Part #790007

Replaced by #790007

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Manufacturer substitution
This part replaces 790007. Substitute parts can look different from the original.
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This item is not returnable
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Brake Disc 790075
#36

Transaxle breakdown diagram

Brake disc

Part #790075

Replaced by #790075

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Manufacturer substitution
This part replaces 790075. Substitute parts can look different from the original.
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Lawn Mower 33-in Deck 2-in-1 Blade (replaces 742-04154a, 942-04154) 942-04154A
#58

Engien/transmission/deck diagram

Lawn mower 33-in deck 2-in-1 blade (replaces 742-04154a, 942-04154)

Part #942-04154A

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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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How to enjoy all the online benefits we offer on our Sears PartsDirect website

Learn about all the convenient features on our Sears PartsDirect website that make your parts purchases easier.…

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

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

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Top questions about Sears and Sears PartsDirect

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