MTD Series 250 User manual

Category
Mini tillers
Type
User manual

This manual is also suitable for

Service Manual
2005 - 250 Series - World Tiller
MTD Products Inc - Product Training and Education Department
FORM NUMBER - 769-02094
10/2005
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 inexperi-
enced 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 Oper-
ators 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
Introduction ............................................................................................................................1
Tines ......................................................................................................................................3
Clutching Mechanism ............................................................................................................4
Gearbox Removal and Replacement. ...................................................................................7
Gearbox Maintenance and Repair. .......................................................................................9
Seal Replacement ...............................................................................................................15
TABLE OF CONTENTS
Vertical Crankshaft Front Tine Tiller
1
1. INTRODUCTION
1.1. Disclaimer: This service manual was intended
for use by trained technicians. The information
contained in this manual is current and accurate
at the time of writing, but is subject to change
without notice.
1.2. Purpose: The vertical crankshaft front tine tiller
was designed to provide a high value tool for
homeowners and gardeners who do not need a
large rear-tine tiller but require something larger
than a cultivator. This product is small enough to
be handy yet large enough to get the job done.
Standard rotating tine tillers excel at turning soil
that has previously been broken. This means
turning-over and introducing compost into exist-
ing flower beds and gardens. While it is capable
of breaking untilled soil, a counter-rotating tine
tiller is better suited to that task. The vertical
crankshaft design yields savings in engine cost.
See Figure 1.2.
1.3. Description: The standard (forward) rotating
tines are driven by a set of worm gears within
the transmission. The tines can be adjusted to till
a swath that varies from 13” (33cm) to 24”
(61cm). The clutching media is a belt that is ten-
sioned between two halves of a split sheave.
One half is attached to the engine, and the other
half is attached to the worm shaft. The friction of
the belt between the two sheave halves trans-
fers power from the engine to the worm shaft at
a 1:1 ratio.
Figure 1.2
1.4. Other Versions: The tiller depicted here is just
one of a variety of vertical crankshaft front-tine
tillers currently in production. See Figure 1.4.
1.5. Versions of this tiller are distributed in Europe.
Features on export tillers vary slightly from
domestic tillers. See Figure 1.5.
Figure 1.4
Figure 1.5
Vertical Crankshaft Front Tine Tiller
Vertical Crankshaft Front Tine Tiller
2
1.6. Different widths and tine configurations are in
production. The T-250 44cm/61cm version has a
disc on the end of the tine shaft to confine trail-
ings. See Figure 1.6.
1.7. The disc can be removed. See Figure 1.7.
1.8. The tines can be reconfigured. See Figure 1.8.
1.9. There is also a T-210 35cm/40cm version,
roughly 50% larger than a mini cultivator.
See Figure 1.9.
Figure 1.6
Figure 1.7
Figure 1.8
Figure 1.9
Vertical Crankshaft Front Tine Tiller
3
2. TINES
2.1. Disconnect and ground the spark plug wire
before servicing or adjusting the tines.
2.2. The tines are easily removed or adjusted using
the hairpin clips and clevis pins that fasten them
to the tine shaft. See Figure 2.2.
2.3. The tines have two types of hub tube: long, and
short.
Figure 2.2
Hairpin
clips
Long hub
Short hub
2.4. There are left and right side tines, each has a
different angle of attack. The tines must sweep
away from the dirt as they enter it. If the tines are
reversed left/right, they will hook into the dirt too
aggressively. See Figure 2.4.
2.5. Keep the tine shaft clear of wire fencing, mono-
filament, clothesline and other material that may
wrap around the shaft.
2.6. Penetrating oil may be used to loosen tines that
are corroded to the tine shaft.
Lubricating the tine shaft before storage will help
prevent this condition.
A small amount of anti-seize between the tine
hub tubes and the tine shaft will help prevent this
condition.
2.7. Replace the tines and the hardware that secures
them to the tine shaft when they become visibly
worn.
Figure 2.4
Left hand tine
Rotation Rotation
Right hand tine
Vertical Crankshaft Front Tine Tiller
4
3. CLUTCHING MECHANISM
3.1. Disconnect and ground the spark plug wire
before performing a service or adjustments to
the clutching mechanism. If the engine has been
recently been run allow it to cool before service
is performed.
3.2. The clutching mechanism consists of the clutch
control lever, clutch cable, belt, upper and lower
sheaves, and belt tensioner.
3.3. Service to most of these components require the
removal of the engine.
3.4. Removal of engine and clutch housing.
See Figure 3.4.
NOTE: Removal steps
Remove the 6 bolts and locking nuts that hold
the clutch housing to the rest of the tiller, using a
pair of 9/16” wrenches.
Lift the engine and clutch housing from the tiller
and place them on a flat level surface without
constraining the cable.
If the engine is to be inverted, drain the gasoline
from the fuel tank.
3.5. To remove the cable, detach the cable from the
handlebars by pushing the barbed bracket out of
the hole. See Figure 3.5.
3.6. Disconnect the Z-fitting from the lever.
3.7. Turn the engine upside-down to gain access to
the cable connection inside the clutch housing.
See Figure 3.7.
NOTE: The orientation of spring is hooking from
the bottom.
Figure 3.4
Figure 3.5
Z-fitting
Clutch control
lever
Figure 3.7
Idler
bracket
Vertical Crankshaft Front Tine Tiller
5
3.8. Remove snap ring that attaches the cable to the
clutch housing.
3.9. Disconnect the cable from the idler bracket.
See Figure 3.9.
3.10. Install the cable by reversing the order of
removal.
3.11. To remove the belt, it will be necessary to
remove the idler bracket
3.12. Disconnect the return spring from the idler
bracket.
3.13. Remove the 3/4 “ hex shoulder bolt and 9/16
lock nut on top side of clutch housing.
See Figure 3.13.
Figure 3.9
Snap ring
Figure 3.13
Shoulder bolt
Idler
return
spring
3.14. Lift the idler bracket and belt out of housing.
See Figure 3.14.
3.15. Remove the lock nut from the stud by using a
9/16” wrench. See Figure 3.15.
NOTE: Belt keeper tabs perform a braking func-
tion when the belt is released.
NOTE: Belt pt# 754-04061 Use of a non-stan-
dard belt may result in poor performance or loss
of braking feature creating a unsafe condition.
Figure 3.14
Figure 3.15
Belt keeper
tabs
Vertical Crankshaft Front Tine Tiller
6
3.16. If it is necessary to remove the top half of the
sheave from the engine crankshaft, apply heat to
the socket head cap screw to release the thread
locking compound. See Figure 3.16.
3.17. Remove the socket head cap screw with a 3/16”
allen wrench. See Figure 3.17.
NOTE: It may be necessary to stop the engine
from turning with either a piston stop or a fly-
wheel holder.
NOTE: The sheave half that is attached to the
crank shaft provides fly weight for the engine.
3.18. At this point the clutch housing can be removed
from the engine using a 9/16” wrench.
3.19. On installation, apply thread locking compound
such as Loctite 242 (blue) the threads and
tighten to torque of 250-270 in-lbs (28-30 n-m)
3.20. With the engine and clutch housing removed,
the tine shield can be lifted off of the tiller.
See Figure 3.20.
NOTE: There are two dowels that locate the tine
shield to the tiller transmission.
3.21. If it is necessary to remove the lower half of the
sheave from the transmission worm shaft, apply
heat to release the thread locking compound.
See Figure 3.21.
NOTE: There is a thin bead of RTV sealant
beneath the tine shield to help exclude dust from
the clutch housing. It does not necessarily seal
to the tine shield.
Figure 3.16
Figure 3.17
Figure 3.20
Figure 3.21
Dowels
RTV
sealant
Vertical Crankshaft Front Tine Tiller
7
3.22. Remove the socket head cap screw and heavy
washer that secure the lower half of the sheave
to the transmission worm shaft using a 3/16”
allen wrench. See Figure 3.22.
3.23. The pulley adapter will slip off of the transmis-
sion worm shaft. It drives the shaft through a
double-D profile.
NOTE: Some 2005 and later tillers may have a
low profile hex-head cap screw in place of the
socket head cap screw. It may be removed using
a 9/16” wrench.
3.24. On installation, apply thread locking compound
such as Loctite 242 (blue) to the threads and
tighten to a torque of 250-270 in-lbs (28-30 n-m).
Figure 3.22
Pulley adaptor
Lower
Pulley
Double-D
Shaft
4. GEARBOX REMOVAL AND REPLACEMENT.
NOTE: The tiller gear box is subject to the like
kind exchange program, providing that the fail-
ure is warrantable.
NOTE: Outside of warranty.the repair vs.
replacement will be at the discretion of the end-
user and the repair shop.
4.1. Begin the transmission removal process by
Removing the engine and clutch housing. See
Figure 4.1.
Remove the 6 bolts and locking nuts that hold
the clutch housing to the rest of the tiller, using a
pair of 9/16” wrenches.
Lift the engine and clutch housing from the tiller
and place them on a flat level surface without
straining the cable.
If the engine is to be inverted, drain the gasoline
from the fuel tank.
4.2. Lift the tine shield off transmission.
Figure 4.1
Vertical Crankshaft Front Tine Tiller
8
4.3. Take note of the tine orientation, then remove
the tines. See Figure 4.3.
4.4. Remove the nut and bolt that hold the front
wheel bracket and tension spring to the trans-
mission using a pair of 7/16” wrenches. See Fig-
ure 4.4.
NOTE: Tighten the wheel bracket bolt to a
torque of 90-120 in/lbs (10-13 n-m) on installa-
tion.
4.5. Remove 2 through-bolts that secure the handle
bars to the gearbox, using a pair of 1/2”
wrenches.
4.6. Remove 2 bolts that hold the depth bar bracket
on the gearbox, using a pair of 9/16” wrenches.
4.7. To install the replacement gearbox simply
reverse the removal process.
See Figure 4.7.
NOTE: When Making service-or-replace deci-
sion about the gearbox, carefully evaluate the
value of the tiller.
If any major damage is discovered to the case,
the bronze gear, or the worm shaft, repair costs
will likely exceed the value of the transmission.
Beyond warranty, confirm the amount that the
customer is willing to spend before commencing
any internal transmission repairs.
Figure 4.3
Figure 4.4
Wheel bracket
bolt
Figure 4.7
Vertical Crankshaft Front Tine Tiller
9
5. GEARBOX MAINTENANCE AND REPAIR.
5.1. Gearbox contains 12 fl/oz. of 85w-140 gear lube.
NOTE: In normal service it should not be neces-
sary to change the gear lube on a regular basis.
The gear lube can be drained and replaced if the
transmission is to be opened for repair, or if the
fluid becomes contaminated, for example by
pressure washing.
NOTE: Damage caused by water in the trans-
mission is NOT warrantable.
5.2. To check the fluid level clean the surface sur-
rounding the fill plug. See Figure 5.2.
5.3. Remove the fill plug with a 7/16” open end
wrench. See Figure 5.3.
NOTE: A bent piece of wire can be used as an
improvised dipstick.
Figure 5.2
Gear lube
fill plug
Figure 5.3
5.4. When filling the gear box with the gear lube be
sure that the gear box is upright position, the oil
level will come up halfway on the tine shaft.
5.5. Drain and properly dispose of the gear lube if the
transmission is to be serviced. Refill it to the
proper level upon completion.
5.6. Before attempting to split the housing, clean the
tine shaft. Remove all dirt, rust, and scale using
emery cloth or a wire wheel.
NOTE: Wear eye protection.
5.7. Remove the 12 perimeter bolts that hold the two
case halves together using a 3/8” wrench, and
separate the housing.
See Figure 5.7.
NOTE: When assembling the gear box:
Clean all components.
Apply gear lube to the surfaces that rotate
against a seal.
Protects seal lips on installation.
Apply RTV sealant such as Permatex Ultra Grey
599BR to the mating surfaces of the case
halves.
Tighten screws to a torque of 90-120 in/lbs (10-
13 n-m).
Figure 5.7
Vertical Crankshaft Front Tine Tiller
10
5.8. Remove the shim from tine shaft inspect for any
wear to the shaft or gears. See Figure 5.8.
5.9. Pull Tine shaft through the gear.
See Figure 5.9.
NOTE: Hi-Pro key between the tine shaft and
the bronze gear.
5.10. Lift the bronze gear out of the housing after the
tine shaft has been removed.
See Figure 5.10.
NOTE: Gear tooth profile is concave to mate
with worm gear.
5.11. Inspect the bronze gear, bronze tine shaft bear-
ings, tine shaft, and housings for significant wear
or damage.
5.12. Remove and inspect worm input shaft for wear
or damage to bearings.
See Figure 5.12.
Figure 5.8
Shim
. 060
Figure 5.9
Hi-Pro
key
Figure 5.10
Figure 5.12
Vertical Crankshaft Front Tine Tiller
11
5.13. To remove the seals, simply pry them up with a
heavy screw driver.
See Figure 5.13.
NOTE: Care must be given not to score the
inside of the gear box casting.
5.14. If it is necessary to remove the bushings from
the housing that may be driven-out from the
inside. See Figure 5.14.
NOTE: The bushing removal tool from the Troy-
Bilt tiller tine shaft tool kit TWX-4006 is the cor-
rect size.
NOTE: If you see that the bushings are in need
of replacement prior to taking out seals you can
press the seals out at the same time your remov-
ing the bushing
Figure 5.13
Figure 5.14
5.15. When installing new bushings, press them in so
that the end of the bushing is even with the
inside boss of the housing. See Figure 5.15.
NOTE: Bushing part number 741-04139
NOTE: If the tiller is need of tine shaft bearings
and the correct bearing (p/n 741-04139) is not
available, Troy-Bilt p/n GW-1086 may be modi-
fied by cutting off 3/8” for a suitable replace-
ment.
5.16. Scribe the GW-1086 bearing against the driven-
out 741-04139 bearing to mark the length. See
Figure 5.16.
Figure 5.15
Figure 5.16
3/8”
Vertical Crankshaft Front Tine Tiller
12
5.17. The GW-1086 bearing may be cut using a tubing
cutter, and dressed to clean any flash or burrs.
See Figure 5.17.
NOTE: When cutting down the bearing, do not
apply enough pressure to distort the bearing. Be
gentle.
5.18. The sheave half is most easily removed from the
worm shaft after the shaft has been removed
from the housing.
5.19. Fixture the shaft in a bench vise, and apply heat
to the socket head cap screw to release the
t h r e a d l o c k i n g c o m p o u n d . S e e F i g u r e 5 . 1 9 .
NOTE: Some tillers may have a hex head cap
screw at this location.
5.20. With the screw and heavy washer removed, the
sheave-half can be lifted away, along with the
adapter. See Figure 5.20.
5.21. With the adaptor removed, the shim washers,
seal, and sealed ball bearing will slip off of the
sha ft . Se e F ig ur e 5 .2 1.
Figure 5.17
Figure 5.19
Hex head cap
screw
Figure 5.20
Pulley
Sheave
Adaptor
Figure 5.21
Vertical Crankshaft Front Tine Tiller
13
5.22. The tapered roller bearing can be pressed off of
the bottom of the worm shaft. See Figure 5.22.
5.23. Inspect the bearings for roughness or obvious
damage. Replace them if necessary.
5.24. Replace the shim washers above the sealed
bearing, followed by a new seal.
See Figure 5.24.
NOTE:
Protect the lip of the new seal on installation.
5.25. Secure the pulley adapter and sheave half to the
worm shaft using the heavy washer and cap
screw. Do not torque the screw or apply thread
locking compound.
Figure 5.22
Figure 5.24
Bearing
Shim washers Oil seal
5.26. Test fit the worm shaft assembly in the housing.
Check end-play. End play should be 0. 0-.014”
(.36 mm). See Figure 5.26.
NOTE: The closer to zero end play, the better.
5.27. Add or remove shims (p/n 736-0266 and 736-
04186) to achieve correct end-play. Generally,
this will not require adjustment.
5.28. Remove the worm shaft from the housing, fixture
it in a bench vise, apply thread-locking com-
pound such as Loctite 242 (blue) to the threads
of the cap screw securing the sheave, and
tighten it to a torque of 250-270 in-lb. (28-30 n-
m). See Figure 5.28.
5.29. Reposition the worm shaft assembly in the hous-
ing.
5.30. Position the first tine shaft thrust washer in the
housing.
Figure 5.26
Figure 5.28
Vertical Crankshaft Front Tine Tiller
14
5.31. Place the bronze gear on top of the thrust
washer, confirming that the holes in the gear, the
thrust washer, and the tine shaft bearing are
aligned. See Figure 5.31.
5.32. Install the tine shaft, hi-pro key, and second
thrust washer.
5.33. Apply a thin bead of RTV sealant such as Per-
matex Ultra Grey 599BR to the mating surfaces
of the case halves. See Figure 5.33.
5.34. Position the second half of the housing, and
secure it using the 12 screws previously
removed. Tighten the screws to a torque of 90-
120 in-lb. (10-13 n-m). See Figure 5.34.
5.35. Install the tine shaft seals. See Figure 5.35.
5.36. Drive the seals all the way in, so that they seat
against the shoulder in the bore.
5.37. Re-fill the case with 12 fl/oz. of 80w140 gear lube
before operation.
5.38. Install the gearbox in the tiller by reversing the
removal process.
Figure 5.31
Figure 5.33
Figure 5.34
Figure 5.35
Vertical Crankshaft Front Tine Tiller
15
6. SEAL REPLACEMENT
NOTE: Replacement of the seals can be done
without removing or disassembling the transmis-
sion.
NOTE: Drain fuel from the fuel tank.
NOTE: If the seal on the left side needs replace-
ment, drain the engine oil as well.
6.1. Position the tiller on its side, with the seal to be
replaced facing up. Remove tines from tine
shaft. See Figure 6.1.
NOTE: It may be necessary to clean the tine
shaft with emery cloth prior to removing the seal.
6.2. Use seal puller tool or heavy screw driver to get
a hold on the old seal.
See Figure 6.2.
NOTE: Use caution not to score the shaft.
Figure 6.1
Figure 6.2
6.3. After the seal is free from the transmission
housing it is possible to slide the seal off by
hand.
See Figure 6.3.
6.4. When the old seal has been removed examine
the tine shaft to for damage to the sealing sur-
face. If the shaft is damaged there are two
options:
Replace the shaft.
Repair the shaft with a locally purchased “Reddi-
sleeve” or similar product.
6.5. Use old micro fiche or similar material to protect
the seal as it slips over the tine shaft.
See Figure 6.5.
Figure 6.3
Figure 6.5
Vertical Crankshaft Front Tine Tiller
16
6.6. Slide the seal along with the protective film or
sleeve into the tine shaft bore in the transmis-
sion housing.
See Figure 6.6.
NOTE: A light coating of oil on the shaft will aid
the film and seal down to the transmission.
6.7. Slide the film out of the seal.
See Figure 6.7.
NOTE: Start the seal in the bore with gentle
thumb pressure.
6.8. Drive the seal home against the with Seal
installer tool from the Troy-Bilt tiller tine shaft tool
kit TWX-4006.
See Figure 6.8.
6.9. Install the tines.
6.10. Confirm correct gear lube and engine oil levels.
6.11. Run and test the tiller before delivery to the cus-
tomer.
Figure 6.6
Figure 6.7
Figure 6.8
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MTD Series 250 User manual

Category
Mini tillers
Type
User manual
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