Part Location Diagram of 121-9178 Toro Transmission
See part E17 in the diagram
( Grid squares measure 1x1 inch )

Transmission 121-9178

Manufactured by:
Toro
ERP Number:
ERP9884543
Part Number:
121-9178
Original Equipment Manufacturer ?
In Stock
Delivers in 3-5 Business Days!

A Bit Difficult 

1- 2 hours 

(13 rated repairs) ?

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Frequently Purchased Together

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Troubleshooting

This part works with the following brands:
  • Toro
This part works with the following products:
  • Lawn Mower

Customer Part Reviews

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4.8
Average Rating (out of 5):
★★★★★
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(5 Reviews)
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Customer Repair Instructions

All our customer repair instructions are solicited directly from other customers just like you who have purchased and replaced this exact part.

A Bit Difficult 

1- 2 hours 

(13 rated repairs) ?
  • 1
  • 2
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The lawn mower was no longer self propelled

Michael from Madison, Connecticut

10 of 10 people found this instruction helpful.
Difficulty Level:
A Bit Difficult
Total Repair Time:
1- 2 hours
Tools:
Pliers, Socket set, Wrench set
Parts Used:
121-9178, 115-4669
1. Figured out how to take the drive transmission out.
a. Removed the handle, plastic and metal shrouds underneath,
b. Removed the drive wheels and metal side plates holding the transmission.
c. Loosened the belt guide at the engine.
d. Removed the drive belt.
e. Removed the transmission from the side plates. Detach from the control cable.
2. Install the new drive belt around the engine pulley, Tighten the belt guide.
3. Do the reverse of the dis-assembly. Grease all rotating parts
4. Start lawn mower and check operation.

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Transmission stopped pulling on my Toro personal pace walk behind mower

Alan from Brandon , Mississippi

10 of 10 people found this instruction helpful.
Difficulty Level:
A Bit Difficult
Total Repair Time:
1- 2 hours
Tools:
Screw drivers, Socket set, Wrench set
Parts Used:
121-9178, 115-4669
Found easy to follow repair instructions on U Tube. followed the step by step instructions. Very easy, just took me a little extra time than the experts seeing how I don\'t do this kind of repairs every day. Replacement parts from Ereplacement parts .com came very quickly and I will certainly use them again.
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Lawn Mower would not self propel

Paul from Arlington Heights, Illinois

5 of 5 people found this instruction helpful.
Difficulty Level:
A Bit Difficult
Total Repair Time:
1- 2 hours
Tools:
Nutdriver, Screw drivers, Socket set, Wrench (Adjustable), Wrench set
Parts Used:
121-9178
Removed the blade, removed belt cover and pulleys. Removed both belts. Removed rear wheels and the right side axle holder, slid transmission out. Replaced transmission and re-assembled.
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Lost self propelled

Glenn from ERIE, Colorado

3 of 3 people found this instruction helpful.
Difficulty Level:
A Bit Difficult
Total Repair Time:
30 - 60 mins
Tools:
Nutdriver, Socket set
Parts Used:
121-9178
Followed excellent video on YouTube.
Removed blade
Removed belt covers
Removed belt
Removed axle pins
Slid out axle/transmission assembly and replaced it
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Mower needed a new transmission

David from SNELLVILLE, Georgia

2 of 2 people found this instruction helpful.
Difficulty Level:
A Bit Difficult
Total Repair Time:
30 - 60 mins
Tools:
Nutdriver, Pliers, Socket set, Wrench (Adjustable), Wrench set
Parts Used:
121-9178
I had watched the video on You tube to see the repair actually in action. This helped in the process of the repair
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Transmission lock-up, worn belt, failed wheel bearings, cracked wheel covers

Kris from PINE, Arizona

1 person found this instruction helpful.
Difficulty Level:
Easy
Total Repair Time:
30 - 60 mins
Tools:
Pliers, Screw drivers, Socket set, Wrench set
Watched Youtube video and followed his instructions, they were mostly correct, my challenges were because of rust and corrosion that wouldn\'t allow easy disassembly. Process too long to type, watch the video.
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Popping in transmission

Roger from Alpharetta, Georgia

1 person found this instruction helpful.
Difficulty Level:
A Bit Difficult
Total Repair Time:
1- 2 hours
Tools:
Pliers, Screw drivers, Socket set, Wrench (Adjustable), Wrench set
Changed out transmission and while at it changed drive belt, bearings, bearing cups.etc.
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Transmission failed

L from Covington, Louisiana

1 person found this instruction helpful.
Difficulty Level:
Easy
Total Repair Time:
30 - 60 mins
Tools:
Pliers, Screw drivers, Socket set, Wrench set
Parts Used:
121-9178
1. Look up on U-Tube how to replace unit followed most of the direction not all of them.
2. After disassembly found that the bushing and bearings on for the axle were bad.
3. When replacing transmission also get the bushing and bearings for the axle
4. Pick up at local shop and replaced both sides
5. The actual wor k time was about on hour.
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Rear-wheel drive wheel would spin when making a turn (transmission). Rear wheel squeak (bearing).

Ralph from EMMAUS, Pennsylvania

0 of 1 people found this instruction helpful.
Difficulty Level:
A Bit Difficult
Total Repair Time:
1- 2 hours
Tools:
Screw drivers, Socket set
Parts Used:
121-9178, 104-8699
1. Remove rear wheels.
2. Remove drive belt covers.
3. Remove one rear wheel support bracket.
4. Remove transmission.
5. Remove bearing from each rear wheel support bracket.
6. Re-assemble in reverse directions.
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Transmission pulley wore out

JAMES from Laredo, Texas

0 of 1 people found this instruction helpful.
Difficulty Level:
Easy
Total Repair Time:
1- 2 hours
Tools:
Socket set
Parts Used:
121-9178
Followed Youtube instructions from ereplacement parts.
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  • 1
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Model Cross Reference

This part works with the following models:
ERP Number: ERP9884543
Manufacturer Part Number: 121-9178
Brand Model Number Description
Toro 20332 Lawn Mower - Lawn Mower
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