Textron JACOBSEN TH300 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
09-346 REV B
MODEL:
73-70920 TRENCHER TH300

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
TRENCHER
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
1-2005
TABLE OF CONTENTS FIGURES PAGE
DESCRIPTION / SPECIFICATIONS .............................................................................................................. 2
SAFETY ..................................................................................................................................................... 3, 4
INSTALLATION .............................................................................................................................................. 5
OPERATION .................................................................................................................................................. 6
SERVICE ....................................................................................................................................................... 7
MAIN FRAME & SHIELDS ................................. FIGURE 1 ..................................................................... 8, 9
DRIVE PARTS ................................................... FIGURE 2 ..................................................................10, 11
BOOM & CHAIN ASSEMBLY ............................. FIGURE 3 ................................................................. 12, 13
HYDRAULICS .................................................... FIGURE 4 ................................................................. 14, 15
GEAR BOX ........................................................ FIGURE 5 ................................................................. 16, 17
CRUMBER ......................................................... FIGURE 6 ................................................................. 18, 19

2
TRENCHER
DESCRIPTION / SPECIFICATIONS
SPECIFICATIONS
Overall Width ............................................................................... 37"
Overall Height .............................................................................. 34"
Overall Length ............................................................................. 64"
Total Weight ................................................................................ 395 lbs.
Auger Diameter............................................................................ 12"
Chain Speed ................................................................................ 550 ft./min.
Drive Shaft (diameter) ................................................................. 1-1/2"
Cutting Depth (max) .................................................................... 28"
Cutting Width ............................................................................... 4-3/4"
DESCRIPTION
The trencher is designed to perform with the Steiner 4-wheel drive articulated frame steering tractors. The
trencher mounts on the quick hitch front lift in the conventional manner. Driven by a PTO belt, a right angle
gearbox provides a 2 to 1 reduction providing power to the trencher digging chain. The depth of trench is
regulated by a cylinder controlled by the auxiliary hydraulic system of the power unit.
Features include:
•Visible depth indicator.
•Front mount Quick Hitch.
•Variable depth control.
•High performance bearings throughout.
•Quick chain tension adjustment.
•Heat treated carbide tip chain.
Trencher easily follows line of trench, cutting to a maximum depth of 28 inches. The depth of cut is easily
adjustable during operation indicated by the highly visible depth gauge.

3
TRENCHER 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. Foryoursafetyandthe safety
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.
GOLF, TURF & SPECIALTY PRODUCTS
MODEL NUMBER
SERIAL NUMBER
JOHNSON CREEK, WI MADE IN U.S.A

4
TRENCHER
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 install drive belt.
2. DO NOT attempt to work on power unit or any
attachments with the engine running. STOP
ENGINE!
3. Before leaving the tractor seat:
•Disengage PTO
• Set PARKING brake.
• Stop engine.
SAFETY
DANGE
R
DO NOT OPERATE WITH BYSTANDERS IN THE
AREA. UNEXPECTED TRENCH CAVE-IN OR
ANY ACTION CAUSING PERSONS TO CONTACT
FAST MOVING DIGGING CHAIN COULD CAUSE
SERIOUS INJURY OR DEATH.

5
TRENCHER INSTALLATION
MOUNTING INSTRUCTIONS
The trencher should be used only on Steiner
4-wheel drive power units equipped with
hydraulic auxiliary couplers.
To mount the trencher do the following steps:
1. Open quick hitch latches. Drive tractor into
position, aligning the quick hitch. Be sure that
both latches are fully engaged and locked.
2. Stop engine to install drive belt. See power unit
operator’s manual for drive belt installation and
tension adjustment.
3. Remove clip pin from support stand and raise
stand to transport position. Secure stand with
clip pin.
4. Connect hydraulic hoses to the auxiliary
couplers. If auxiliary hydraulic lever seems to
operate in the wrong direction, connect the
hoses in the opposite couplers.
UNMOUNTING INSTRUCTIONS
1. Choose a level site to remove the trencher.
2. Lower the support stand and secure with clip
pin.
3. Lower the front lift. Lower the boom and apply
slight down pressure.
4. Set parking brake and stop engine.
5. Disconnect hoses from the quick couplers.
6. Remove drive belt.
7. Open quick hitch latches. Start engine and
back power unit away from the trencher.

6
TRENCHER
OPERATION
OPERATING INSTRUCTIONS
1. Attach trencher to quick hitch front lift, placing
correct drive belt around the left hitch arm.
2. Stop engine and install the drive belt. Adjust
tension if equipped with adjustment. Remove
clip pin from support stand and secure the
support stand in the transport position.
3. Start engine and transport the trencher to the
job site.
4. Align and position the boom of the unit with the
line of trench to be dug.
5. Check the location of existing electric, gas or
water lines before digging.
6. Check the area for obstacles such as loose
rocks, stones, wood and other debris that could
hinder proper operation of the trencher.
7. Lower the front lift and place the lift lever in the
“FLOAT” position.
8. Engage the PTO carefully with engine at
approximate half throttle. Slowly lower the
boom to the depth of trench desired using the
auxiliary hydraulic lever. (Do not place this
lever in the float position.)
9. Carefully move the F - R lever to move the unit
in reverse. MOVE VERY SLOWLY!
10. Avoid sharp turns while digging a trench. Sharp
turns place extreme loads on the trencher
attachment.
11. In the event the digging chain gets wedged
between rocks or caught in a root or other solid
object, be ready to disengage the PTO drive.
Raise the boom to clear the obstacle before
trying to restart the PTO.
IMPORTANT!
THE TRENCHER IS DESIGNED TO DIG WHILE
THE UNIT IS TRAVELING IN REVERSE
DIRECTION. DO NOT ATTEMPT TO DIG WITH
THE UNIT TRAVELING IN A FORWARD
DIRECTION.
DANGE
R
DO NOT OPERATE WITH BYSTANDERS IN THE
AREA. UNEXPECTED TRENCH CAVE-IN OR
ANY ACTION CAUSING PERSONS TO CONTACT
FAST MOVING DIGGING CHAIN COULD CAUSE
SERIOUS INJURY OR DEATH

7
TRENCHER SERVICE
SERVICE SCHEDULE
Every 4 Hours:
• Grease the boom pivot tube.
Daily:
• Check for any signs of loose bolts and tighten
as needed.
• Check digging chain for missing or broken
cutters. Repair as needed. Check digging
chain tension.
• Wash boom, digging chain and auger at the
end of each workday.
25 hour:
• In addition to daily service, lubricate the roller
chain with chain lube or SAE 30 motor oil.
• Check gearbox oil level. Oil level is 4 inches
down from the top of filler tube. Use #90 gear
oil.
100 hour:
• Change gearbox oil at 100 hours or four
weeks initially, and every 2500 hours or six
months of operation thereafter. Use #90 gear
oil.
ADJUSTMENTS
Drive belt tension:
• See the power unit operators manual for
adjustment of drive belt tension.
Roller chain drive:
• Adjustment is by a spring loaded idler.
Digging chain tension:
• Adjust with large set screw in the center of
boom. Loosen jam nut and tighten set screw
until chain has 1/4 inch to 1/2 inch gap when
lifted from the boom at mid—point. Tighten
jam nut.
Crumber adjustment:
• The crumber should be close to, but not
touching, the digging chain at any time. The
unit may need to be moved out as the digging
chain stretches. Choose from three mounting
hole positions.
NOTE:
DO NOT OVERTIGHTEN CHAIN. This will
cause undue wear on the boom
components.
Replacing digging chain:
1. Loosen four bolts through the boom.
2. Loosen jam nut on the set screw in the center of
the boom and back out the set screw to allow
the boom to retract.
3. Remove the old chain and replace with the new
chain.
4. Tignten the set screw until the chain is snug.
Tighten the jam nut. Tighten the bolts that were
loosened in Step 2.
5. Check new digging chain tension (as described
above) after it has run for 20 minutes, and every
hour of use for the next 4 hours.
NOTE: It is normal for a new chain to require
frequent tightening.

8
TRENCHER
MAIN FRAME & SHIELDS
FIGURE 1

9
TRENCHER
ITEM PART NO. DESCRIPTION QTY ITEM PART NO. DESCRIPTION QTY
MAIN FRAME & SHIELDS
FIGURE 1
1-1 62-823.7 MAIN FRAME 1
* 4116761 LBL-MADE IN USA 1
1-2 60-625.7 SHIELD-AUGER 1
* 00-223 LBL-DANGER STAND CLEAR1
1-3 44-140 DEFLECTOR BELTING, DIRT 1
1-4 64139-08 BOLT-5/16-18X3/4 5
1-5 64141-6 NUT, 5/16-18 5
1-6 44-141 BELTING, AUGER 1
1-7 64-855 STRAP, BELTING 1
1-8 64123-75 BOLT, 3/8-16X3 HEX 3
1-9 64141-4 NUT-WLF 3/8-16 10
1-10 64139-24 BLT-WLF 3/8-16 X 1 4
1-11 64-849 CLAMP, BELTING 1
1-12 4134161 TUBE AND HOSE CLMP 1/4" 2
1-13 01-014 SCREW, MACHINE 8-32 X 1 1
1-14 64025-29 NUT-HEX #8-32 KEPS 2
1-15 64-834.7 FOOT STAND W/A 1
1-16 64123-87 BOLT-HEX 3/8-16X1-3/4 1
1-17 64229-03 LOCKNUT-NYLON 3/8-16 1
1-18 03-0616 CLEVIS PIN, 3/8 X 2 1
1-19 02-PP0313 PIN, 3/16 x 1.5/8 1
1-20 60-626.7 SHIELD, DRIVE BELT 1
* 00-025 LBL-HANDS & FEET 1
1-21 90-0808 BOLT 4
1-22 64163-67 WASHER-.516X1X12GA 4
1-23 64006-05 LOCKWSHR-HELICAL 1/2 4
1-24 64139-02 BLT-WLF 1/4-20X1/2 7
1-25 64141-2 NUT-WLF 1/4-20 1
1-26 64-848.7 BRACE, CHAIN SHIELD 1
1-27 60-624.7 GUARD, CHAIN 1
* 00-093 LBL-WARN OWNR MAN 1
* 00-223 LBL-DANGER STAND CLEAR1
1-28 64139-21 BLT-WLF 3/8-16X3/4 3
1-29 60-628.7 COVER, CHAIN GUARD 1
* 00-217 LBL-MODEL TH300 1
* 00-223 LBL-DANGER STAND CLEAR1
1-30 60-629.7 COVER, ACCESS 1
1-31 64123-89 BOLT-HEX 1/4-20X3/4 1
1-32 64163-03 WSHR-.256ID X.62OD X 18 1
1-33 64229-01 LOCKNUT-NYLON 1/4-20 1
1-34 64-851.7 CLAMP, BOOM SWIVEL 1
1-35 64229-02 LOCKNUT-NYLON 5/16-18 2
1-36 64163-02 WSR-.321/.328X.593/.608X11 4
1-37 64123-55 BLT-HEX 5/16-18X3 2
1-38 64-847.7 CLAMP, BELTING 1
1-39 44-142 BELTING, RUBBER 1
1-40 64-861.7 STRAP, AUGER BELTING 1
1-41 64152-61 8-32 X 1 1/4 MACH SCRW 2
* NOT ILLUSTRATED

10
TRENCHER
DRIVE PARTS
FIGURE 2

11
TRENCHER
ITEM PART NO. DESCRIPTION QTY ITEM PART NO. DESCRIPTION QTY
DRIVE PARTS
FIGURE 2
2-1 62-823.7 FRAME, MAIN W/A 1
2-2 80-192.7 AUGER, TRENCHER W/A 1
2-3 CLAMP-AUGER 1
(SUPPLIED W/64-836)
2-4 64123-171 BOLT-HEX 3/8-16X3-1/2 2
2-5 64229-03 LOCKNUT-NYLON 3/8-16 2
2-6 64164-26 KEY-3/8x3/8x1-1/2 SQ 3
2-7 64-854 SPACER-AUGER 1
(USED WITH STANDARD DIGGING CHAIN)
64-924 SPACER-AUGER 1
(USED WITH 5-1/2" CHAIN KIT)
2-8 83-041 DRV SPRKT-W/ 3/8 KEYWAY 1
2-9 60-630.7 SHIELD 2
2-10 55-1108KRR BRG-FAFNIR W/COLLAR 1
2-11 80-253 SHAFT-DRIVE 1
2-12 55-RA108RR BRG-FAFNIR W/COLLAR 1
2-13 60-624.7 GUARD, CHAIN 1
2-14 87-175 GEARBOX, RIGHT ANGLE 1
2-15 29-079 PIPE NIPPLE, 1/2 X 1.1/2 1
2-16 24-033 PIPE CAP, 1/2" 1
2-17 83-BK85H PULLEY-8.5" H1 BUSHING 1
2-18 D3032 BUSHING, H 7/8 1
2-19 64164-11 KEY-3/16X3/16X1-1/4 SQ 1
2-20 81-B050 BELT-B51 1
(USED ON 415 & 430)
2-21 64006-05 LOCKWSHR-HELICAL 1/2 5
2-22 90-0808 BOLT 4
2-23 83-60Q40 SPROCKET, 60Q40 1
2-24 56-RC60-42CHAIN-#60 42" 1
81-024 CONNECTOR LINK #60 1
81-077 HALFLINK-#60 1
2-25 83-Q124 BUSHING-Q1 X 1-1/2" 1
2-26 83-H601220SPRKT-FIXED BORE 1-1/4 1
2-27 64164-10 1/4X1/4X1-1/4 MACH KEY 1
2-28 40-322.7 ARM, IDLER 1
2-29 83-6015E08IDLER SPRKT #60 15TTH 1/2 1
2-30 85-B29 BUSHING,.406 X.740 X.258 1
2-31 41-020 SPRING 1
2-32 64123-70 BOLT-HEX 3/8-16X1-1/2 1
2-33 64123-50 BOLT-HEX 3/8-16X1 1
2-34 64123-24 BLT-HEX 1/2-13X2 1
2-35 64163-61 WSHR .81X.406X16GA 2
2-36 64163-67 WASHER-.516X1X12GA 2
2-37 64025-09 HEX, NUT 1/2-13 1
2-38 64141-4 NUT-WLF 3/8-16 3
2-39 56-068 TRIM SEAL 12" 1

12
TRENCHER
BOOM & CHAIN ASSEMBLY
FIGURE 3

13
TRENCHER
ITEM PART NO. DESCRIPTION QTY ITEM PART NO. DESCRIPTION QTY
BOOM & CHAIN ASSEMBLY
FIGURE 3
3-1 62-821.7 BOOM 1
(INCLUDES ITEMS 4 - 11)
3-2 90-0826 BOLT,1/2-13 X 3-1/4 4
3-3 64141-13 NUT WLF 1/2-13 4
3-4 92-12 NUT,3/4-10 1
3-5 85-105-372SET SCREW-3/4 X 5 1
3-6 87-105-379BOLT-3/4 X 1-1/4 1
3-7 87-110-054BUSHING 2
3-8 87-115-464SNAP RING 1
3-9 87-142-755ROLLER 1
3-10 87-125-009BEARING 1
3-11 87-183-469IDLER SHAFT 1
3-12 79-080 CHAIN-DIGGING 4-3/4" 1
(STANDARD)
* 70-125 KIT-3-1/2" TRENCHER CHN 1
(OPTIONAL)
62-861 CRUMBER WLDMT 1
79-098 CHAIN-3-1/2" WIDE 1
* 70-117 KIT-5-1/2" TRENCHER CHN 1
(OPTIONAL)
64-924 SPACER-AUGER 1
79-099 CHAIN-5-1/2" WIDE 1
3-1/2" CHAIN REPAIR LINKS
3-13 79-090 REPAIR SECTION 1
(CENTER CUT)
3-14 79-091 REPAIR SECTION 3" 1
(LH STRAIGHT)
3-15 79-092 REPAIR SECTION 3" 1
(RH STRAIGHT)
3-16 79-103 REPAIR SECTION 1
(OFFSET LEFT)
3-17 79-104 REPAIR SECTION 1
(OFFSET RIGHT)
3-18 79-102 REPAIR SECTION 1
(3-1/2" DOUBLE)
4-3/4" CHAIN REPAIR LINKS
* 79-101 REPAIR SECTION 1
(4-3/4" DOUBLE)
5-1/2" CHAIN REPAIR LINKS
* 79-093 REPAIR SECTION 1
(4" DOUBLE)
* 79-095 REPAIR SECTION 1
(5" DOUBLE)
* 79-096 REPAIR SECTION 1
(5-1/2" DOUBLE)
* NOT ILLUSTRATED

14
TRENCHER
HYDRAULICS
FIGURE 4

15
TRENCHER
ITEM PART NO. DESCRIPTION QTY ITEM PART NO. DESCRIPTION QTY
HYDRAULICS
FIGURE 4
4-1 23-070 CYLINDER, HYD. 2 X 8 1
21-13055X SEAL KIT 1
4-2 64-852 TOP PIN 1
4-3 02-CP0512 COTTER PIN, 5/32 X 1-1/2 4
4-4 25-2103-6-6 FITTING-90 DEG. 2
4-5 20-017 HOSE-1/4 X 70 2
4-6 25-0103-4-6 FITTING-STR 2
4-7 23-004 MALE QUICK COUPLER 2
4-8 64-853 BOTTOM PIN 1
4-9 64-846 SPACER, DEPTH GAUGE 1
4-10 64-839.7 DEPTH GAUGE W/A 1
4-11 02-CP0410 COTTER PIN, 1/8 X 1-1/4 1
4-12 56-073 GAUGE, DEPTH 1
4-13 62-822.7 FRAME, BOOM PIVOT W/A 1
4-14 64-835.7 SAFETY TUBE W/A 1
00-224 LABEL 3
(DANGER FOR TRENCHER)
4-15 99-K56 BOLT-FLANGE 1/2-13X1-1/2 4
4-16 64141-13 NUT WLF 1/2-13 4
4-17 29-010 S/B GREASE FITTING 1

16
TRENCHER
GEAR BOX
FIGURE 5

17
TRENCHER
ITEM PART NO. DESCRIPTION QTY ITEM PART NO. DESCRIPTION QTY
GEAR BOX
FIGURE 5
5-1 87-CM000182 HOUSING 1
5-2 87-CM450064 COLLAR 1
5-3 87-CM150144 BEARING CUP 2
5-4 87-CM150136 BEARING CONE 2
5-5 87-CM370023 SHIM (.010) VARIES
5-6 87-CM370015 SHIM (.005) VARIES
5-7 87-CM620062 RETAINING RING 1
5-8 87-CM410233 LOCKWASHER 1
5-9 87-CM410255 LOCKNUT 1
5-10 87-CM600031 KEY 1
5-11 87-CM050237 HUB 1
5-12 87-CM450585 COLLAR 1
5-13 87-CM620088 RETAINING RING 1
5-14 87-CM200287 SHAFT 1
5-15 87-CM300251 SEAL 1
5-16 87-CM150151 BEARING CONE 1
5-17 87-CM150011 BEARING CUP 1
5-18 87-CM410163 SEMS CAP SCREW 16
5-19 87-CM390021 GASKET (.015) 1
5-20 87-CM390039 GASKET (.005) 1
5-21 87-CM390195 GASKET (.003) 1
5-22 87-CM101030 GEAR 1
5-23 87-CM055327 THRU CAP 1
5-24 87-CM452326 COLLAR 1
5-25 87-CM600171 KEY 1
5-26 87-CM222810 THRU SHAFT 1
5-27 87-CM301473 SEAL 1
5-28 87-CM150557 BEARING CONE 1
5-29 87-CM150540 BEARING CUP 1
5-30 87-CM101048 PINION 1
5-31 87-CM410027 PIPE PLUG (SOLID) 2
5-32 29-079 PIPE NIPPLE, 1/2 X 1.1/2 1
5-33 24-033 PIPE CAP, 1/2" 1

18
TRENCHER
CRUMBER
FIGURE 6