Can’t find your part?   Contact us:
+1-309-603-4777
Sears Parts Direct
Orders

  • Keep track of the models you own in your profile

    Sign in or Register to view or add models

Schedule a repair
MTD
Front-Engine Lawn Tractor

Model # 13AL78XT099 Official MTD tractor

Here are the diagrams and repair parts for Official MTD 13AL78XT099 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”.

We encourage you to save the model to your profile, so it’s easy to access parts and manuals for your appliance whenever you log in.

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

Owner’s manual
  View engine

Model diagram and schematic

SEARCH WITHIN THIS MODEL

?

This is the number corresponding to the part on the diagram / schematic

Search
ALL PARTS
Showing 10 of 509 parts  |
Troybilt Lawn Tractor Blade Engagement Cable (replaces 946-05124) 946-05124A
#22

Frame/battery diagram

Troybilt lawn tractor blade engagement cable (replaces 946-05124)

Part #946-05124A

BEST SELLER
$34.69 | 
15% OFF Phone Price : $40.69
In Stock
Lawn & Garden Equipment Cotter Pin, 1/4- To 5/16-in 714-04040
Lawn & garden equipment cotter pin, 1/4- to 5/16-in

Part #714-04040

BEST SELLER
This item is not returnable
$3.00 | 
25% OFF Phone Price : $4.00
In Stock
Lawn Tractor 46-in Deck 2-in-1 Blade 942-04290
#45

Deck/spindle assembly diagram

Lawn tractor 46-in deck 2-in-1 blade

Part #942-04290

Replaced by #942-04290A

?
Manufacturer substitution
This part replaces 942-04290. Substitute parts can look different from the original.
BEST SELLER

Get free shipping with Automatic Reorder

$22.79 | 
21% OFF Phone Price : $28.79
In Stock
Yard Machines Lawn & Garden Equipment Lock Nut, 5/16-18 (replaces 753-05591) 712-04063
Yard machines lawn & garden equipment lock nut, 5/16-18 (replaces 753-05591)

Part #712-04063

BEST SELLER
This item is not returnable
$4.40 | 
19% OFF Phone Price : $5.40
In Stock
Exhaust Gasket BS-692236
#7

Engine/muffler diagram

Exhaust gasket

Part #BS-692236

Replaced by #692236

?
Manufacturer substitution
This part replaces BS-692236. Substitute parts can look different from the original.
BEST SELLER
$6.56 | 
13% OFF Phone Price : $7.56
In Stock
Ace Lawn & Garden Equipment Self-tapping Bolt, 5/16-18 X 3/4-in (replaces 1724491, 1740496, 1909304, 910-1260a, Gw-7101260) 710-1260A
Ace lawn & garden equipment self-tapping bolt, 5/16-18 x 3/4-in (replaces 1724491, 1740496, 1909304, 910-1260a, gw-7101260)

Part #710-1260A

BEST SELLER
This item is not returnable
$4.25 | 
19% OFF Phone Price : $5.25
In Stock
Lawn Tractor 46-in Deck Mulching Blade (replaces 33188, 742-04268) 942-04268
#NI

Deck/spindle assembly diagram

Lawn tractor 46-in deck mulching blade (replaces 33188, 742-04268)

Part #942-04268

BEST SELLER

Get free shipping with Automatic Reorder

$30.93 | 
16% OFF Phone Price : $36.93
In Stock
Lawn Tractor Bearing (replaces 741-04124) 941-04124
#16

Steering diagram

Lawn tractor bearing (replaces 741-04124)

Part #941-04124

BEST SELLER
This item is not returnable
$6.10 | 
14% OFF Phone Price : $7.10
In Stock
Yard Machines Lawn & Garden Equipment Nut 712-04064
Yard machines lawn & garden equipment nut

Part #712-04064

BEST SELLER
This item is not returnable
$4.49 | 
18% OFF Phone Price : $5.49
In Stock
Lawn Tractor Gauge Wheel 734-04155
#31

Deck/spindle assembly diagram

Lawn tractor gauge wheel

Part #734-04155

BEST SELLER
$23.42 | 
20% OFF Phone Price : $29.42
In Stock

RECOMMENDED MAINTENANCE PARTS AND ACCESSORIES

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

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

View all

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

Main causes: faulty battery, bad alternator…

Read more

Why does my riding mower deck vibrate?

Main causes: damaged cutting blade, worn deck pulley, damaged mandrel pulley, loose fasteners on mower deck components…

Read more

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…

Read more

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…

Read more

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

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

Read more

Why is my riding mower leaking oil or gas?

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

Read more

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…

Read more

Why does my riding mower creep in neutral?

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

Read more

Why won't my riding mower move?

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

Read more

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.

View all
How to replace the starter motor on a riding lawn mower

How to replace the starter motor on a riding lawn mower

If you hear the solenoid click but don’t hear the starter motor spin when you turn the key, follow these steps to replac…

Read more
Repair difficulty
Time required
 30 minutes or less
How to rebuild a riding lawn mower carburetor

How to rebuild a riding lawn mower carburetor

Get your sputtering carburetor running smoothly in 60 minutes.…

Read more
Repair difficulty
Time required
 60 minutes or less
How to replace a riding lawn mower rear tire

How to replace a riding lawn mower rear tire

Your mower can’t run on a damaged rear tire. Here’s how to install a new one.…

Read more
Repair difficulty
Time required
 60 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.

View all
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.…

Read more
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.…

Read more
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.…

Read more

Parts & More