Textron JACOBSEN MC400 Setup guide

WARNING: If incorrectly used this machine can cause severe injury. Those who use
and maintain this machine should be trained in its proper use, warned of its dangers
and should read the entire manual before attempting to set up, operate, adjust or
service the machine.
OWNER/OPERATOR’S MANUAL
& ILLUSTRATED PARTS LIST
09-323 REV A
MODEL:
73-70805 TREE FARM MOWER 44 MC400

CALIFORNIA
Proposition 65 Warning
Diesel engine exhaust and some of
its constituents are known to the State
of California to cause cancer, birth
defects and other reproductive harm.
Californie Proposition 65
Avertissement
Les échappements des moteurs diesel
et certains de leurs composés sont
reconnus par l’Etat de Californie pour
être cancérigènes, provoquer des
défauts congénitaux et d’autres dangers
en matière de reproduction.
ADVERTENCIA
AVERTISSEMENT
WARNING
The engine exhaust from this product
contains chemicals known to the State
of California to cause cancer, birth
defects or other reproductive harm.
California Advertencia
de la Proposicion 65
El estado de California hace saber que
los gases de escape de los motores
diesel y algunos de sus componentes
producen cáncer, defectos de
nacimiento y otros daños en el
proceso de reproducción humana.
L’ é mission du moteur de ce mat é riel
contient des produits chimiques que
l’Etat de Californie consid è re ê tre
canc é rig è nes, provoquer des d é fauts
cong é nitaux et d’autres dangers en
mati è re de reproduction.
El estado de California hace saber
que los gases de escape de este
producto contienen productos
quÍmicos que producen cáncer,
defectos de nacimiento y otros daños
en el proceso de reproducción
humana.
© 2003, TEXTRON INC

1
TREE FARM
MOWER
IMPORTANTMESSAGE
Thank you for purchasing this Jacobsen product. You have purchased a world class product, one of the best
designed and built anywhere.
This product comes with an Owner/Operator's Manual. The useful life and good service you receive from this
product depends to a large extent on how well you read and understand this manual. Treat this product properly
and adjust it as instructed, and it will give you many years of reliable service.
See a Jacobsen dealer for any service or parts needed. Jacobsen service ensures that you continue to receive
the best results possible from Jacobsen products. You can trust Jacobsen replacement parts because they are
manufactured with the same high precision and quality as the original parts.
Jacobsen designs and builds its equipment to serve many years in a safe and productive manner. For longest
life, use this product only as directed in the manual, keep it in good repair and follow safety warnings and
instructions. You'll always be glad you did.
Jacobsen, a Textron Company
One Bob Cat Lane
Johnson Creek, WI 53038-0469
9-2003
TABLE OF CONTENTS FIGURES PAGE
INTRODUCTION / SPECIFICATIONS........................................................................................................... 2
SAFETY ..................................................................................................................................................... 3, 4
ASSEMBLY INSTRUCTIONS ........................................................................................................................ 5
INSTALLATION .............................................................................................................................................. 6
OPERATION .................................................................................................................................................. 7
SERVICE .................................................................................................................................................. 8-10
PARTS SECTION .........................................................................................................................................11
MAIN DECK ....................................................... FIGURE 1 ................................................................. 12, 13
FRAME AND HITCH PARTS.............................. FIGURE 2 ................................................................. 14, 15
FRONT WHEEL SHIELDS................................. FIGURE 3 ................................................................. 16, 17
REAR WHEEL SHIELDS ................................... FIGURE 4 ................................................................. 18, 19
GEARBOX (A).................................................... FIGURE 5 ................................................................. 20, 21
GEARBOX (B).................................................... FIGURE 6 ................................................................. 22, 23
GEARBOX (C) ................................................... FIGURE 7 ................................................................. 24, 25
GEARBOX (D) ................................................... FIGURE 8 ................................................................. 26, 27

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TREE FARM
MOWER
INTRODUCTION / SPECIFICATIONS
SPECIFICATIONS
Mower Overall Width ................................................................... 45-1/2"
Cutting Width ............................................................................... 44"
Overall Length ............................................................................. 79" including wheel shields
Rear Fender Width with 20 X 8.00-10 turf tires........................... 43-1/4"
Rear Fender Width with standard tires........................................ 46-1/4"
Cutting Height .............................................................................. 2" to 5"
Mower Drive................................................................................. PTO Belt
Spindle Drive ............................................................................... Gearbox and 2 V-belts
Spindle Bearings ......................................................................... 1" Ball Bearings
Blades .......................................................................................... 2 Blades, 22-1/2"
Discharge..................................................................................... Rear
Caster Wheel............................................................................... 10 X 3.5, Semi-pneumatic
Weight.......................................................................................... 272 lbs. approx.
DESCRIPTION
The Model MC400 Tree Farm Mower is designed to fit the 420 tractor equipped with standard tires or
optional 20 X 8.00-10 turf type tires. The mower is easy to attach and detach in a minute or less allowing
interchange with many other front mounted attachments. Cutting height is controlled by the front caster
wheel. Exceptional visibility and maneuvering is possible with this front mounted design mower. Shielded
tractor wheels keep the unit from damaging the lower branches of young trees or shrubs. Two mowing
blades discharge grass to the rear and enable the mower to cut tall grass. This is an ideal unit for mowing
between closely spaced rows of trees or shrubbery.

3
TREE FARM
MOWER SAFETY
NOTICE !!!
Unauthorized modifications may present extreme
safety hazards to operators and bystanders and
could also result in product damage.
Jacobsen, a Textron Company strongly warns
against, rejects and disclaims any modifications,
add-on accessories or product alterations that are
not designed, developed, tested and approved by
Jacobsen Engineering Department. Any Jacobsen
product that is altered, modified or changed in any
manner not specifically authorized after original
manufacture–includingtheadditionof“after-market”
accessories or component parts not specifically
approved by Jacobsen–will result in the Jacobsen
Warranty being voided.
Anyandallliabilityforpersonalinjuryand/orproperty
damagecausedbyanyunauthorizedmodifications,
add-on accessories or products not approved by
Jacobsen will be considered the responsibility of
the individual(s) or company designing and/or
making such changes. Jacobsen will vigorously
pursuefullindemnification andcosts fromanyparty
responsibleforsuchunauthorizedpost-manufacture
modifications and/or accessories should personal
injury and/or property damage result.
This symbol means:
ATTENTION!
BECOME ALERT!
Your safety and the safety of others is involved.
Signal word definitions:
The signal words below are used to identify levels
of hazard seriousness. These words appear in this
manual and on the safety labels attached to
Jacobsenmachines. Foryoursafetyand thesafety
ofothers,readandfollowtheinformationgivenwith
thesesignalwordsand/orthesymbolshownabove.
DANGER indicates an imminently hazardous
situationwhich,if notavoided,WILL result indeath
or serious injury.
WARNING indicates a potentially hazardous
situation which, if not avoided, COULD result in
death or serious injury.
CAUTION indicates a potentially hazardous
situation which, if not avoided, MAY result in minor
or moderate injury. It may also be used to alert
against unsafe practices or property damage.
CAUTION used without the safety alert symbol
indicates a potentially hazardous situation which, if
not avoided, MAY result in property damage
MODEL NUMBER: This number appears on
sales literature, technical manuals and price
lists.
SERIAL NUMBER: This number appears only
on your mower. It contains the model number
followed consecutively by the serial number.
Use this number when ordering parts or seeking
warranty information.

4
TREE FARM
MOWER
1. Read and understand the Owner’s Manual before attempting to operate this machine.
2. Operate all controls from the operator’s seat. NO RIDERS.
3. Keep all shields in place and safety switches adjusted properly.
4. Do not leave equipment unattended. STOP the engine and remove the key.
5. Do not allow minors or the inexperienced to operate this machine.
6. Keep people and pets a safe distance away from machine using power driven attachments. Injury
could result from flying debris.
GENERALSAFETY
OPERATINGSAFETY
1. STOP ENGINE to make repairs or adjustments.
Do not attempt to work on unit or attachments
with the engine running.
2. Before leaving the operator's seat:
• Disengage mower drive.
• Set Parking brake.
• Stop Engine.
SAFETY
KEEP HANDS AND FEET AWAY FROM
ROTATING BLADES.
BE ALERT FOR DEBRIS IN THE PATH OF THE
MOWER. STICKS, STONES AND OTHER
OBJECTS CAN CAUSE SERIOUS DAMAGE TO
THE ATTACHMENT.

5
TREE FARM
MOWER ASSEMBLY INSTRUCTIONS
1. Remove mower from crate.
2. Remove top shield and remove bag of small fastener parts. Separate according to size.
3. If optional 20 X 8.00-10 turf-type tires are being used, move each wheel hub in toward the center of the
tractor a distance of 3/4 inch or a total distance of 1-1/2 inches from the end of the axle. Mount optional
tires in the usual manner.
4. Remove the drive pulley shield and install drive belt Part No. 81-A040. Replace shield. Attach the
mower to the tractor quick-hitch front lift in the usual manner.
5. Fill gearbox to 1/8" pipe plug on front of gearbox with 80/90 gear oil.
6. To install front skirts - Mount directly on deck mounts using a 3/8 x 3/4 flange bolt and nut at the front.
When using standard tires, fasten skirts to rear of mower at desired height with 2" spacers and 5/16 X
2-3/4 bolts and nuts on each side. If optional 20 x 8.00-10 tires are used, fasten skirts to rear of mower
at desired height using two 5/16 X 3/4 bolts and nuts on each side. (See Parts Figure 3)
7. To install rear wheel skirts - Remove front and rear fenders saving the bolts and nuts. Replace the
fenders with the skirts using the same bolts and nuts. Two sets of mounting holes are provided. One
set is for narrow setting with the 20 x 8.00-10 turf-type tires. The other set of holes is for use with
standard bar type tires. (See Photo 5 and Parts Figure 4) Install support brackets from parts package
to tread plate using the same bolts which fastened the fenders to tread plate. Attach brackets to skirts
with 1/4 x 3/4 flange bolts and nuts.
8. Do not use both bar tires and turf tires at the same time. This is important because the tires are not the
same size and the rolling radius is different. Different size tires could cause premature failure of the
transaxles.

6
TREE FARM
MOWER
INSTALLATION
ATTACHING MOWER TO TRACTOR:
1. Operate latch control to open hitch latches.
2. Drive tractor into position aligning the quick hitch.
3. Be sure both latches engage fully and are laced in the locked position.
NOTE: Stop engine! Do not attempt to install drive belt with engine running.
4. Release idler assembly to facilitate easy installation of the drive belt.
5. Put belt over drive pulleys and engage idler assembly.
6. Set mower to desired cutting height by moving the 3 clevis pins at the 3 attaching points of the support
frame. See photos below for front and rear height adjustment.
7. Start engine and engage PTO slowly to prevent shock load on mower components.
8. Mow with front lift lever in “FLOAT” position only.
FRONT HEIGHT ADJUSTMENTREAR HEIGHT ADJUSTMENT

7
TREE FARM
MOWER OPERATION
OPERATING INSTRUCTIONS
- Set mower cutting height. See Installation Page 6.
- Mow with front lift lever in “FLOAT” position only.
- Engage PTO slowly at low engine r.p.m.
- Mower is designed to operate at full throttle for heavy mowing, but 3/4 throttle is adequate for average
conditions.
- Set mower blade speed with the throttle and control ground speed with the Forward - Reverse control
lever.
- Trimming can be done along either side of the mower deck. Wheel shields keep the unit from
damaging the lower branches of young trees.
- Use extreme caution when operating on hills.
- A roll bar is recommended.
- Mow up and down hills whenever possible.
- A rear weight bar with 2 weights is recommended.
Observe all Safety Decals.
Keep all Shields in place.
Do not operate mower with other persons in the area. Irregularities in
ground surface can permit foreign material to be propelled from
beneath deck to cause serious injury or death.
Before leaving tractor, move Forward - Reverse control to neutral
position, disengage PTO, set parking brake, lower mower deck and
stop engine.
Remove key from ignition if maintenance procedures are to be
performed or tractor is to be left unattended.
The mower deck is enclosed on all sides to prevent foreign material
from being propelled from beneath deck toward operator or
bystanders. Keep all shields in place!

8
TREE FARM
MOWER
SERVICE
MAINTENANCE
Daily maintenance:
Visual inspection for loose parts and accumulation of grass and dirt.
Clean accumulation of grass clippings from beneath deck daily for better mowing performance.
Keep blades sharp. Check the tips of the blades for wear.
25 hour maintenance:
In addition to daily maintenance, grease caster, slip yoke and all bearings.
Remove top shield and grease spindle bearings. Grease the spindle bearings beneath the deck also.
Do not overgrease.
Check gearbox oil level, fill to 1/8" pipe plug on front of gearbox with 80/90 gear oil.
Annual Maintenance:
In addition to daily and 25 hour maintenance, check the drive belts for cracks or wear. Rotate each
spindle to check for roughness which would indicate bearing wear. Remove and sharpen blades, clean
and wash deck prior to storage. The acid in grass clippings causes premature corrosion and rusting of
mower parts.
ADJUSTMENTS
Sharpening blades:
Be careful while sharpening blades that the corners of the blade do not become rounded at the tips. This
reduces the blades overlap and will cause skipping. While sharpening, it is essential to ensure the balance
of the blades is maintained to prevent vibration. Blade bolt torque should be 75-85 foot pounds. Rotate
blades after re-installing to check for bent or bowed blades and blade alignment.
Blade alignment:
When installing sharpened blades or new blades be sure the mating surfaces are clean and the retaining
washer is not bent. Check for bent blades by rotating blades until tips are near each other.
Leveling mower deck:
The front to rear and side to side leveling adjustment is provided by 3 clevis pins.
Example for low cutting: If rear pins are in the top hole, the front pin will be in the bottom hole.
If the rear pins are moved down one hole, the front pins will be moved up one hole.