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Craftsman
Riding Mowers & Tractors

Model # 3904 Official Craftsman lawn tractor

Here are the diagrams and repair parts for Official Craftsman 3904 lawn tractor, as well as links to manuals and error code tables, if available.

There are a couple of ways to find the part or diagram you need:

  • Click a diagram to see the parts shown on that diagram.
  • In the search box below, enter all or part of the part number or the part’s name.

Not all parts are shown on the diagrams—those parts are labeled NI, for “not illustrated”.

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For DIY troubleshooting advice and repair guides, visit our repair help section.

Model diagram and schematic

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ALL PARTS
Showing 10 of 758 parts  |
Blade 66071-6176-0
#110

Blade - cover diagram

Blade

Part #66071-6176-0

The manufacturer no longer makes this part, and there's no substitute part

Wire 66071-5329-0
#80

Panel diagram

Wire

Part #66071-5329-0

The manufacturer no longer makes this part, and there's no substitute part

Bolt 01133-5102-0
#120

Rear axle diagram

Bolt

Part #01133-5102-0

The manufacturer no longer makes this part, and there's no substitute part

Bumper 66071-5121-0
#20

Frame diagram

Bumper

Part #66071-5121-0

The manufacturer no longer makes this part, and there's no substitute part

Switch 66071-5176-0
#160

Mower link, lift lever diagram

Switch

Part #66071-5176-0

The manufacturer no longer makes this part, and there's no substitute part

Snap Pin 05516-5100-0
#50

Bonnet - hood diagram

Snap pin

Part #05516-5100-0

The manufacturer no longer makes this part, and there's no substitute part

Assy Mower, Rclt 66071-6150-0

#NI

All parts diagram

Assy mower, rclt

Part #66071-6150-0

The manufacturer no longer makes this part, and there's no substitute part

Cover 66071-2232-0
#30

Brake diagram

Cover

Part #66071-2232-0

The manufacturer no longer makes this part, and there's no substitute part

Cir-clip 04613-0007-0
Cir-clip

Part #04613-0007-0

The manufacturer no longer makes this part, and there's no substitute part

Spring 66071-5422-0
#60

Bonnet - hood diagram

Spring

Part #66071-5422-0

The manufacturer no longer makes this part, and there's no substitute part

Most common symptoms to help you fix your riding mowers & tractors

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

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Why won't my riding mower cut grass?

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

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How do I charge a dead battery on my riding mower?

Main causes: faulty battery, bad alternator…

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How do I fix a flat tire on my riding mower?

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

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Why won't my riding mower start?

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

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Why is the steering loose on my riding mower?

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

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Why does my riding mower creep in neutral?

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

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Why does my riding mower run rough or misfire?

Main causes: clogged carburetor, damaged flywheel key, dirty spark plug, stale fuel, improper valve lash, engine needs a…

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Why won't my riding mower move?

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

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Why is my riding mower not cutting evenly?

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

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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.

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How to replace a mandrel assembly on a riding lawn mower

How to replace a mandrel assembly on a riding lawn mower

Replace the mandrel assembly if the blade shaft vibrates or doesn't spin.…

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Repair difficulty
Time required
 30 minutes or less
How to replace the flywheel key on a riding lawn mower

How to replace the flywheel key on a riding lawn mower

If the engine won't restart after hitting a stump or rock, the problem could be a sheared flywheel key. Follow these ste…

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Repair difficulty
Time required
 60 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…

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Repair difficulty
Time required
 30 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.

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

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.…

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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.…

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Riding lawn mower engine clicks but doesn't turn over video

Riding lawn mower engine clicks but doesn't turn over video

Check the starter solenoid, starter motor, wiring, battery and engine.…

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