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MTD 678 lawn tractor Parts

Here are the diagrams and repair parts for MTD 678 lawn tractor, as well as links to manuals and error code tables, if available.

MTD 678 lawn tractor
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Browse Parts for 678 Riding Mowers & Tractors

  • Tiller Belleville Washer for MTD 678 - Part 936-0253

    Speed control diagram

    Washer

    Part #736-0253

    Replaced by #936-0253

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    Manufacturer substitution
    This part replaces 736-0253. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $5.86
    15% OFF Phone Price : $6.86Info Icon
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  • Yoke-brake for MTD 678 - Part 961-0198B

    Transmission diagram

    Brake Yoke

    Part #761-0198

    Replaced by #961-0198B

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    Manufacturer substitution
    This part replaces 761-0198. Substitute parts can look different from the original.
    In Stock
    $36.89
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  • Ace Tiller Carburetor Nut for MTD 678 - Part 912-0158

    Hex Nut

    Part #712-0158

    Replaced by #912-0158

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    Manufacturer substitution
    This part replaces 712-0158. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $5.94
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  • Lawn Tractor Muffler for MTD 678 - Part 951-0617C

    Muffler-sgl

    Part #751-0617

    Replaced by #951-0617C

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    Manufacturer substitution
    This part replaces 751-0617. Substitute parts can look different from the original.
    In Stock
    $163.26
    7% OFF Phone Price : $175.26Info Icon
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  • Lawn Tractor Blade Drive Belt for MTD 678 - Part 954-0440

    Deck "h" diagram

    Belt

    Part #754-0440

    Replaced by #954-0440

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    Manufacturer substitution
    This part replaces 754-0440. Substitute parts can look different from the original.
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    In Stock
    $70.76
    8% OFF Phone Price : $76.76Info Icon
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  • Lawn & Garden Equipment Hex Nut for MTD 678 - Part 912-0138

    Hex Nut

    Part #712-0138

    Replaced by #912-0138

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    Manufacturer substitution
    This part replaces 712-0138. Substitute parts can look different from the original.
    In Stock
    $11.86
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  • Transmission Bracket for MTD 678 - Part 17840-0637

    Drive diagram

    Mounting Bracket

    Part #17840

    Replaced by #17840-0637

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    Manufacturer substitution
    This part replaces 17840. Substitute parts can look different from the original.
    In Stock
    $21.23
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  • Lawn Tractor Fuel Tank Cap for MTD 678 - Part 751-0603B

    Seat and main frame diagram

    Fuel Cap

    Part #751-0603

    Replaced by #751-0603B

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    Manufacturer substitution
    This part replaces 751-0603. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $37.72
    14% OFF Phone Price : $43.72Info Icon
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  • Seat Support for MTD 678 - Part 17950A-0637

    Seat and main frame diagram

    Bracket

    Part #17950

    Replaced by #17950A-0637

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    Manufacturer substitution
    This part replaces 17950. Substitute parts can look different from the original.
    In Stock
    $33.22
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  • Torsion Spring for MTD 678 - Part 932-0742

    Transmission diagram

    Torsion Spring

    Part #732-0742

    Replaced by #932-0742

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    Manufacturer substitution
    This part replaces 732-0742. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $8.80
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Most common symptoms to help you fix your riding mowers & tractors

Choose a symptom to see related riding mower and lawn tractor repairs.

Main causes: damaged tie rods, bent or worn wheel spindle, worn front axle, damaged sector gear assembly…

Main causes: dead battery, stale fuel, bad starter solenoid, ignition system problem, bad ignition interlock switch, clo…

Main causes: worn or broken blade belt, broken belt idler pulley, blade clutch cable failure, bad PTO switch, damaged ma…

Main causes: engine overfilled with oil, leaky head gasket or sump gasket, damaged carburetor seals, cracked fuel pump, …

Main causes: punctured tire or inner tube, leaky valve stem, damaged wheel rim…

Main causes: unlevel mower deck, dull or damaged cutting blades, worn mandrel pulleys, bent mower deck, engine needs tun…

Main causes: worn or broken ground drive belt, bad seat switch, transaxle freewheel control engaged, transaxle failure, …

Main causes: faulty battery, bad alternator…

Main causes: shift lever needs adjustment, neutral control needs adjustment…

Most common repair guides to help fix your riding mowers & tractors

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

How to replace the starter solenoid on a riding lawn mower

How to replace the starter solenoid on a riding lawn mower

Replace the starter solenoid if it doesn't click when you turn the ignition key.…

Repair time and Difficulty

 30 minutes or less
How to replace a riding lawn mower ignition coil

How to replace a riding lawn mower ignition coil

If you're not getting spark from a good spark plug, the problem could be the ignition coil. Follow these step-by-step in…

Repair time and Difficulty

 30 minutes or less
How to replace a riding lawn mower fuel filter

How to replace a riding lawn mower fuel filter

Help your mower run better by replacing the fuel filter during your riding mower's annual tune-up.…

Repair time and Difficulty

 15 minutes or less

Effective articles & videos to help repair your riding mowers & tractors

Use the advice and tips in these articles and videos to get the most out of your riding mower or lawn tractor.

Top questions about Sears and Sears PartsDirect

Top questions about Sears and Sears PartsDirect

Get answers to frequently asked questions about Sears and Sears PartsDirect.…

Wiring schematic symbols explained video

Wiring schematic symbols explained video

Learn some of the most common symbols found in a wiring diagram and what they mean.…

Jump-starting a riding lawn mower battery video

Jump-starting a riding lawn mower battery video

Learn how to connect cables safely to jump-start your mower’s battery.…

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