Troy-Bilt 600 Series Service Manual

Service Manual

600 Series AutoDrive Lawn Tractor

NOTE: These materials are for use by trained technicians who are experienced in the service and repair of outdoor power
equipment of the kind described in this publication, and are not intended for use by untrained or inexperienced individuals.
These materials are intended to provide supplemental information to assist the trained technician. Untrained or inexperi­enced individuals should seek the assistance of an experienced and trained professional. Read, understand, and follow
all instructions and use common sense when working on power equipment. This includes the contents of the product’s
Operators Manual, supplied with the equipment. No liability can be accepted for any inaccuracies or omission in this pub­lication, although care has been taken to make it as complete and accurate as possible at the time of publication. How­ever, due to the variety of outdoor power equipment and continuing product changes that occur over time, updates will be
made to these instructions from time to time. Therefore, it may be necessary to obtain the latest materials before servicing
or repairing a product. The company reserves the right to make changes at any time to this publication without prior notice
and without incurring an obligation to make such changes to previously published versions. Instructions, photographs and
illustrations used in this publication are for reference use only and may not depict actual model and component parts.

© Copyright 2005 MTD Products Inc. All Rights Reserved

MTD Products Inc - Product Training and Education Department

FORM NUMBER - 769-01799

4/2005

Steering Adjustments

IMPORTANT: The front tires will have a "TOE-

IN" between 1/16" and 5/16" to allow the unit to
track properly.

1). Check the tire pressure in the front tires and
make certain that they are at approximately 14
PSI.

2). Place the unit on level ground.

3). Place the steering wheel in the straight forward
position.

4). Lower the deck lift lever to the lowest position.

5). Line up the centering hole in the steering gear
with the centering hole in the support plate, and
insert a 1/4" Phillips screw driver up through
both. See figure 1.

6). In front of the axle, measure the distance hori­zontally from the inside of the left rim to the
inside of the right rim. See figure 2.

FIGURE 1.

7). From behind the axle, measure the distance hori­zontally from the inside of the left rim to the
inside of the right rim.

8). The measurement taken in front of the axle
should be between 1/16" and 5/16" less than the
measurement taken behind the axle. If not, per­form the following steps:

9). Loosen the jam nut at the rear of the right ball
joint that secures the ball joint to the drag link
using a 1/2" wrench and an 11/16" wrench. See
figure 3.

FIGURE 2.

FIGURE 3.

10). Remove the hex nut and lock washer that
secures the right ball joint to the right axle
assembly using a 1/2" wrench and a 9/16
wrench.

11). Remove the right hand ball joint from the right
hand drag link.

12). Remove the left hand ball joint performing steps
9, 10, and 11 above.

13). Place the left and right tire assemblies in the
straight forward position.

14). Set the toe-in for the rim assemblies to the prop­er measurements as described in steps 6, 7, and
8 above.

15). Thread the right hand ball joint onto the right
hand drag link until the mounting hole in the right
hand axle assembly lines up with the ball joint.

NOTE: Count the number of turns the ball joint
was rotated onto the drag link. This number
should be equal for the left side as well.

Centering

Hole

Jam Nut

1

Step Through Rider

Adjustments

Variable Speed Drive

16). Secure the right hand ball joint to the right hand
axle assembly with the lock washer and nut
removed earlier, using a 1/2" wrench and a 9/16
socket.

17). Secure the right hand ball joint jam nut to the
right hand drag link using a 1/2" wrench and an
11/16 wrench.

FIGURE 1.

IMPORTANT: The AutoDrive pedal is properly

adjusted when the hole found in the double-idler
bracket has approximately 1-3/8" of travel with
ten pounds of pressure applied to the AutoDrive
pedal. See figures 1 and 2.

Autodrive Pedal Adjustment

1). Locate the speed control assembly on the
underside of the steering support bracket.

2). Remove both hairpin clips from the main pin on
the speed control assembly. See figure 3.

10 Lbs.

Double Idler

Bracket

1-3/8"

FIGURE 2.

FIGURE 3.

NOTE: Be careful not to lose the small flat

washers found on the main pin.

NOTE: Make certain both hairpins are put back
in from the top of the main pin during reassem­bly.

3). Remove the AutoDrive pedal return spring.

4). Using two 9/16" wrenches, remove the main pin
from the speed control assembly.

5). Thread the idler adjustment rod inward or out­ward until the proper adjustment has been
achieved.

REASSEMBLE THE AUTODRIVE PEDAL IN THE
REVERSE ORDER ABOVE.

Main Pin

Hairpin

Clips

2

18). Install the left hand ball joint using steps 15, 16,
and 17.

NOTE: Make certain the same amount of rota­tions are used on the left ball joint as the right
ball joint.

Variable Speed Drive

Brake Adjustments

IMPORTANT: Make certain the tractor comes to

a complete stop when the brake pedal is
depressed. Also, make certain the rear wheels
do not roll when the parking brake has been
applied. If motion continues, perform the follow­ing steps:

1). Locate the hex nut that secures the brake
assembly.

2). Loosen (DO NOT REMOVE) the hex nut using a
1/2" wrench.

3). Slide an .011" feeler gauge between the brake
disc and the brake puck. See figure 1.

FIGURE 1.

4). Tighten the hex nut that secures the brake
assembly.

5). Remove the .011" feeler gauge from the brake
assembly.

6). Test for proper adjustments.

Hex Nut

Feeler Gauge

Leveling the Cutting Deck

NOTE: Prior to leveling the mowing deck, per-

form the following steps:

1). Check the tire pressure. The front tires will be
approximately 14 PSI, and the rear tires will be
approximately 10 PSI.

2). Place the tractor on a level surface.

3). Depress and lock the parking brake.

4). Place the cutting deck in cutting position 3 or 4.

FRONT TO REAR ADJUSTMENT:

IMPORTANT: The front of the deck will be

between 1/4" to 3/8" lower in the front than the
rear of the deck.

1). Using a work glove or rag, rotate the blades until
they are parallel with the tractor frame. See
figures 1 and 2.

FIGURE 1.

3

Variable Speed Drive

2). Measure the front blade tips to ground.

3). Measure the rear blade tips to ground.

4). Make certain the front blade tips are 1/4" to 3/8"
lower in the front than the rear blade tips.

FIGURE 2.

FIGURE 3.

NOTE: If an adjustment is needed, perform the

following steps:

5). Loosen both two jam nuts on the rear side of the
deck stabilizer bracket using a 3/4" wrench. See
figure 3.

FIGURE 4.

Rear

Front

Jam Nuts

6). Locate both lock hex nuts on the front side of the
deck stabilizer bracket. See figure 4.

Lock Nuts

7). Tighten both lock hex nuts to raise the front of
the deck or loosen both lock hex nuts to lower
the front of the deck using a 3/4" wrench.

8). Retighten both jam nuts on the rear side of the
deck stabilizer when the proper adjustment has
been achieved.

SIDE TO SIDE ADJUSTMENT:

IMPORTANT: The cutting deck must be even

side to side.

1). Using a work glove or rag, rotate the blades until
they are cutting edge tip to cutting edge tip
(perpendicular) to the tractor. See figure 5.

FIGURE 5.

4

Variable Speed Drive

FIGURE 6.

2). Measure the outer blade tips to ground. Both
measurements taken should be equal. See figure

6.

FIGURE 7.

4). Rotate the 3/4" deck adjustment gear right or left
until the deck is level side to side and both blade
tips to ground are equal in measurement.

5). Retighten the hex cap screw on the left deck
hanger using a 1/2" and 3/4" wrench when the
proper adjustment has been achieved.

FIGURE 8.

NOTE: If an adjustment is needed, perform the

following steps:

3). Loosen (DO NOT REMOVE) the hex cap screw
on the left deck hanger bracket using a 1/2" and
a 3/4" wrench. See figure 7.

Side

Equal

Side

Hex Cap

Screw

NEW ADJUSTMENT DESIGN

Adjustment

Gear

4 - 5

5

Variable Speed Drive

Deck Belt Removal and Installation

42" CUTTING DECK:

1). Lower the deck to the lowest position.

2). Pull the PTO idler pulley and bracket towards the
discharge chute, relieving belt tension. See
figure 1.

FIGURE 1.

3). Remove the deck belt from the electric PTO
clutch on the engine.

4). Remove the self tapping screws securing the
spindle belt covers. See figure 2.

FIGURE 2.

5). Remove the spindle belt covers.

6). Remove the PTO deck belt.

REINSTALL THE NEW BELT IN THE REVERSE
ORDER ABOVE.

46" CUTTING DECK:
LOWER BELT:

1). Pull the lower deck belt flat idler and idler bracket
towards the left side of the tractor, relieving the
belt tension. See figure 1.

2). Remove the lower deck belt.

REINSTALL THE NEW BELT IN THE REVERSE
ORDER ABOVE.

Electric

PTO

Clutch

Idler

Pull

Screws

Cutting Deck Removal

1). Lower the lift lever to the lowest setting.

2). Pull the PTO idler pulley and bracket towards the
side discharge chute. See figure 1.

FIGURE 1.

Idler

Pull

Electric

PTO

Clutch

6

Variable Speed Drive

FIGURE 2.

5). Pivot the deck support pins to the rear.

6). Raise the lift lever to the highest setting. This will
raise the lift arms up and out of the way of the
deck assembly.

7). Slide the cutting deck forward and release the
front deck hangers off of the front stabilizer rod.
DO NOT DROP the deck to the ground. See
figure 3.

FIGURE 3.

8). Slide the deck towards the side discharge chute
and remove it from the tractor.

CAUTION: Remove the deck stabilizer assembly
from the tractor prior to moving the unit.

3). Remove the deck belt from the lower pulley on
the engine.

NOTE: The 46" decks have an upper and a
lower belt. The upper belt is removed for cutting
deck removal.

4). Pull the rear deck support pins outward from the
deck lift arms. See figure 2.

Deck Support

Pin

Lift

Arm

Front

Stabilizer

Rod

Drive Belt Removal and Reinstallation

TRANSMISSION BELT REMOVAL AND
INSTALLATION:
UPPER BELT:

1). Raise the seat of the tractor and disconnect the
battery cables from the battery. Remove the
negative cable first. See figure 1.

FIGURE 1.

7

Variable Speed Drive

2). Remove the battery strap, battery, and the
battery tray from the tractor. See figure 2.

FIGURE 2.

3). Raise the deck lift lever to the highest position.

4). Pull the transmission idler pulley towards the
transmission and release the upper drive belt.
See figure 3.

FIGURE 3.

5). Slowly release the idler pulley.

6). Remove the upper drive belt from the transmis­sion pulley and the variable-speed pulley. See
figure 4.

NOTE: Slowly roll the drive belt off of the
variable-speed pulley.

FIGURE 4.

Upper Drive

Belt

Pull

Upper Drive

Belt

VARIABLE-SPEED BELT REMOVAL AND
REINSTALLATION:
LOWER BELT:

IMPORTANT: Prior to lower variable speed belt

removal, perform cutting deck removal and upper
drive belt removal.

1). Remove the hex bolt and lock nut securing the
variable-speed pulley to the transmission using a
9/16 socket and a 9/16 wrench. See figure 5.

FIGURE 5.

9/16"

Wrench

9/16"

Socket

8

Variable Speed Drive

2). Raise the variable speed pulley and roll the lower
drive belt off.

3). Remove the variable-speed pulley from the trac­tor through the battery box opening.

4). Disconnect the wiring harness female connector
from the reverse safety switch.

5). Loosen (DO NOT REMOVE) the flat moving idler
on the double-idler bracket. See figure 6.

FIGURE 6.

6). Remove the variable-speed belt from the double
idler pulley assembly.

7). Cut and remove the zip tie securing the PTO
clutch wires to the wiring harness.

NOTE: Make certain a new zip tie is reinstalled
during reassembly.

8). Carefully disconnect the wiring harness connec­tor from the electric PTO clutch assembly. See
figure 7.

FIGURE 7.

NOTE: During reassembly, make certain the

PTO clutch wires are routed inside the right hand
drag link.

9). Remove the hex bolt that secures the electric
PTO clutch to the engine crank shaft using a 5/8
socket.

NOTE 1: Some units have a washer that rests on
top of the electric PTO clutch, make certain it is
in place during reassembly.

NOTE 2: Torque the hex bolt to 38 to 50 foot­pounds during reassembly.

NOTE 3: Make certain that the clutch retaining
pin is in the electric PTO clutch bracket during
reassembly.

10). Slowly lower the engine drive pulley and remove
the variable-speed belt. See figure 8.

Wiring

Harness

Connector

Zip Tie

FIGURE 8.

Variable

Speed Belt

Engine

Pulley

NOTE: Carefully set the engine drive pulley

aside, making certain the 1/4" squared key
remains in place.

11). Remove the variable-speed belt from the tractor.

REINSTALL THE VARIABLE-SPEED BELT IN THE
REVERSE ORDER ABOVE.

9

Variable Speed Drive

Transmission Removal and Installation

NOTE: Prior to performing transmission removal

and installation, it is necessary to remove the
upper drive belt.

1). Remove both rear hub caps from the rear wheel
assemblies.

2). Loosen both hex cap screws securing the rear
wheel assemblies to the axles.

3). Raise the rear of the tractor off the ground.

4). Remove both center hex cap screws and bell
washers from the rear wheel assemblies.

5). Remove both rear wheel assemblies from the
tractor.

6). Disconnect the reverse safety switch. See figure

1.

FIGURE 1.

7). Remove the hair pin that secures the shift link­age to the shift fork and set the shift linkage
aside. See figure 2.

FIGURE 2.

Reverse Safety Switch

Hairpin

8). Remove both of the self tapping screws that
secure the transmission to the front torque brack­et using a 3/8 socket. See figure 3.

FIGURE 3.

9). Support the bottom of the transaxle.

10). Remove all four hex bolts and lock nuts securing
the transmission to the frame using a 1/2" socket
and a 1/2" wrench. See figure 4.

FIGURE 4.

11). Remove both transmission mounting brackets
from the top of the frame.

12). Remove the hex bolt and lock nut securing the
variable-speed pulley to the transmission using a
9/16 socket and a 9/16 wrench.

13). Remove the locking hex nut from the brake actu­ation arm on the transmission. See figure 5.

NOTE: During reassembly, perform the brake
adjustment section.

Transmission

Mounting

Bracket

10

Variable Speed Drive

FIGURE 5.

15). Pivot the anti-rotation bracket down and relieve
the spring tension on the brake actuation arm.

16). Remove the flat washer from the actuation arm
stud of the brake assembly.

17). Remove the brake spring from the brake actua­tion arm. See figure 5.

FIGURE 6.

NOTE: The variable-speed pulley will be hanging

by the drive belt at this time. Set it aside after
removal of the transmission.

INSTALL THE TRANSMISSION IN THE REVERSE
ORDER ABOVE.

Hex

Nut

Anti-Rotation

Bracket

Hex

Screw

Brake

Spring

Long

Screws

11

14). Loosen (DO NOT REMOVE) the hex washer
head self-tapping screw that secures the anti­rotation bracket to the brake assembly using 3/8
wrench. See figure 5.

18). Slowly lower the transmission from the tractor.

See figure 6.