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TROUBLE SHOOTING
AND
E
N
H
O
T SI
G
S
N
I
I
M
D
S
L
I AN
U
B TR
E
R 4J
T-8
By Robert Notman
This book is dedicated to those unsung heroes of world war two—the mechanics and drivers. Without their dedication and duty to their machines the
troops on the line would not have been the best equipped army in the field.
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Published by Robert V. Notman
Tallahassee, Florida USA
Copyright © 2004 by Robert V. Notman
ALL RIGHTS RESERVED
First Edition
No part of this book may be reproduced in any form, in an
electronic retrieval system or otherwise, without the prior
written permission of the copyright owner. Contact:
[email protected]
Printed in the United States of America.
Other Copyright or Trademarks Notices: JeepTM is a trademark of DaimlerChrysler. The word jeep is a noun used to collectively describe those wartime vehicles built by American BantamTM, FordTM and of course, WillysOverlandTM. All trademarks and copyright marks belong to their respective
owners, lack of trademark or copyright indicator is in no way meant to detract
from their owners right of ownership or use. Manufacturers or vendors listed
here do not indicate endorsement of any kind by those manufacturers or vendors. Pictures credited as noted.
Disclaimers: Some of the information posted here was correct for the day but
has since been replaced because of modern safety concerns. If you choose
to use any of the information you do so at your own risk. Please try to use
common sense and be careful!
CAUTION: Working with machinery can be dangerous, please use common sense and use safe practices. Be sure to wear eye and ear protection. Use tools as they were designed to be used. Using screwdrivers
can be hazardous.
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TABLE OF CONTENTS
INTRODUCTION
1
Noisy T-84J debunked?
What parts do I need to purchase?
How much time to repair and replace the transmission?
4
6
7
Which vendors should you buy your parts from?
Shifting the transmission
1942 Ford GPW and 1941 Willys MB
Transmission trouble and remedies
Concerns and sage advice...
New seal to stop lube pumping from the transfer case
9
10
11
12
14
16
Cluster shaft tool
Transmission details
Transmission variations
-Pre-standardized BRC T-84 transmission
18
20
21
-Pre-standardized MA T-84 transmission
-“Early” standardized WW2 jeep T-84J transmission
-“Mid” standardized WW2 jeep T-84J transmission
-“Late” standardized WW2 jeep T-84J transmission
-The Weasel T-84 transmission
What the heck is that thing for?
Bearings
Lube specifications
Sore as a boil about oil
U.S. and British lube equivalents
Saving a worn case
Parts diagram and list
Your jeep jump outta gear?
Sticking shift-lever on 1/4-tons
22
23
25
26
27
28
29
31
33
35
36
38
40
42
(Continued on next page)
i
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TABLE OF CONTENTS
(CONTINUED)
DISASSEMBLY
43
Before you begin…
Remove gearshift housing
Remove clutch release bearing
Remove main drive gear bearing retainer
Remove shifter fork guide rail
Remove the low and reverse, and the second
and high shifter forks
Removing shifter shafts
Remove counter shaft and idler shaft lock plate
Remove counter shaft
Main drive gear removal
Remove mainshaft
Remove idle reverse gear
Cluster gear removal
Disassemble countershaft gear
Disassemble main drive gear
Disassemble synchronizer
Disassemble mainshaft
44
46
49
51
53
55
CLEANING
Cleaning the parts…
57
59
60
61
62
64
65
66
67
70
71
73
74
77
INSPECTION AND REPAIR
Transmission case assembly
Shifter plate
Main drive gear
Mainshaft
First and reverse gear
Second gear
Countershaft gear
Idler gear
Countershaft and idle gear shaft
Synchronizer
How to double clutch!
Main drive gear bearing rollers
Ball bearings
Countershaft thrust washers
First and reverse shifter fork
Second and third shifter fork
Shift lever
78
80
81
84
85
87
89
91
93
95
96
97
98
99
100
101
102
(Continued on next page)
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TABLE OF CONTENTS
(CONTINUED)
ASSEMBLY
103
Install idle gear
Install cluster gear
Assemble mainshaft
Install internal seal
Install mainshaft assembly
Assemble main drive gear
Install main drive gear assembly
Install countershaft
Install lock plate
Wire mainshaft and main drive gear
Install first and reverse shifter fork
Install second and third shifter fork
Install guide rail
Install shifter shaft plate and washer
Install gearshift housing on case
Install front bearing retainer
Install cup, transmission second and third gear
shifter shaft oil retainer
Install gearshift lever
Install interlock plunger
Install clutch release bearing
104
105
108
112
113
117
119
120
122
123
125
128
131
132
133
134
138
FINAL THOUGHTS...
INDEX
140
141
142
144
149
iii
Page 75
use a block of wood, a vise
and a hammer...
...to gently knock the bearing
from the shaft.
TROUBLE SHOOTING AND REBUILDING THE T-84J TRANSMISSION
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DISASSEMBLE
SYNCHRONIZER
Source: TM 9-1803B
No.
Synchros seem to be available
in two versions...one’s that
work and one’s that don’t! I
have taken brand new synchros
out of the box and couldn’t get
the clutch hub to separate from
the clutch sleeve.
I would advise caution when
purchasing a new synchro
since some are not any good.
Make sure the vendor has a
good return policy. Two vendors that I have had success
with transmission parts are
Brent Mullin Jeep Parts and
Richard Grace..
Willys Part
No.
Ford Part
No.
Name
1
637834
GPW-7107
Transmission Synchronizer
Blocking Ring
2
637831
GPW-7109
Transmission Synchronizer
Spring
3
637833
GPW-7106
Transmission Second and
Direct Speed Clutch Sleeve
4
637835
GPW-7059
Transmission High and Intermediate Clutch Hub Snap
Ring
5
637830
GPW-7105
Transmission High and Intermediate Clutch Hub
Transmission Synchronizer
Doesn’t mean that other deal6
637832
GPW-7116
Shifting Plate
ers are just as good...it’s just
that I have had nothing but success buying parts from these guys. Both
it (except for the potential problems with
vendors have always worked with me if I
new ones already mentioned!)
had a problem with a part.
While the topic here is “dissemble synchronizer,” I don’t believe it is worth the trouble.
Purchase a new synchro and be done with
Page 70
Don’t reuse the existing synchro as worn
blocking rings or other parts can lead to
problems in shifting.
TROUBLE SHOOTING AND REBUILDING THE T-84J TRANSMISSION
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DISASSEMBLE MAINSHAFT
Start by removing the snap ring. Of
course, your ability to remove the ring
depends on whether you have the
“early” style spacer or the later spacer
that has a recess for the snap ring.
If you have a recessed snapring and
spacer combination you are going to
have to move the bearing. Simply put it
loosely in a vise. Use your trusty 2x4 as
a buffer and then hammer the “short”
end of the mainshaft to move the bearing away from the spacer.
Caution: Not pictured is the “oil baffle”,
also called the “slinger”. Use care in
moving the bearing with the method described above. If the slinger is in place
with the recessed snap ring, then you
can use a small section of pipe with a
diameter just large enough to fit over the
mainshaft AND spacer….then hammer
as before.
TROUBLE SHOOTING AND REBUILDING THE T-84J TRANSMISSION
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Page 78
This is a spacer with the recess for the snapring. This
could be in your transmission or you might have the
spacer without. If you want to use the seal in the transmission, you will need to use this type spacer.
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TROUBLE SHOOTING AND REBUILDING THE T-84J TRANSMISSION
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G
N
I
N
A
E
L
C
CAUTION: Working with machinery can be dangerous,
please use common sense and use safe practices. Be sure
to wear eye and ear protection. Use tools as they were designed to be used. Using screwdrivers can be hazardous.
TROUBLE SHOOTING AND REBUILDING THE T-84J TRANSMISSION
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Page 80
CLEANING THE PARTS...
I use commonly available brake cleaner. Simply spray
it on and generally it quickly cleans the parts.
Wash all parts thoroughly in dry-cleaning
solvent until all trace of old lubricant has
been removed. Oil the bearing surfaces immediately after cleaning to prevent corrosion of the highly polished surfaces.
You should strive for a grease and oil free case so that
you can get a good seal when you assemble the parts.
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TROUBLE SHOOTING AND REBUILDING THE T-84J TRANSMISSION
Page 81
As you clean each part, look it over for excessive
wear, pitting or broken teeth.
Cleaning the shafts of all residue will make the inspection phase so much easier.
TROUBLE SHOOTING AND REBUILDING THE T-84J TRANSMISSION
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You are basically looking for the same
things on each gear...
...and that would be wear, pitting, and missing teeth. The bushings should be looked
over as well but we will look at all those issues more closely during inspection.
Use a pan to collect the waste liquid left over from cleaning the
transmission parts. Dispose of this
chemical in accordance with your
local laws.
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TROUBLE SHOOTING AND REBUILDING THE T-84J TRANSMISSION
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N
O
I
T
R
I
C
A
E
P
P
S
E
N
R
I D
N
A
CAUTION: Working with machinery can be dangerous,
please use common sense and use safe practices. Be sure
to wear eye and ear protection. Use tools as they were designed to be used. Using screwdrivers can be hazardous.
TROUBLE SHOOTING AND REBUILDING THE T-84J TRANSMISSION
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Page 84
TRANSMISSION CASE
ASSEMBLY
Inspect the case and gearshift housing for cracks or damage of any
kind. Cracked or damaged units
must be replaced. You will also
want to check the case where the
bearings insert to see if there is excessive wear. Check the Clutch release lever fulcrum for excessive
wear.
Take a new bearing, insert it into a
clean case and see if you can get
any side to side movement, if so
your case will need to be replaced
or requires some work not covered
here.
CLUTCH RELEASE LEVER FULCRUM
Source: TM 9-1803B
According to Jim Gilmore, a transmission case can be saved by having the case machined and a bushing made to fit the case and the
bearing. That is beyond the scope
of this project but should provide
you with an idea of how you can
save your valuable case.
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TROUBLE SHOOTING AND REBUILDING THE T-84J TRANSMISSION
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BIBLIOGRAPHY
Power Transmission, Chapter XVIII, The Army Mechanic, Quartermaster Depot, Baltimore, MD 1938
The Jeep—It’s Development and Procurement Under
The Quartermaster Corps, 1940-1942, Herbert R.
Rifkind, Washington. D.C., 1943
The Military Jeep Model MB-GPW (revised edition),
Lawrence Nabholtz. Linden, TX., 1999.
TB 9-1859-8, Time Schedule Guide, 5 September
1952 (available as a reprint from Portrayal Press)
Hopefully, with the advice from this book and your newly
repaired T-84J, you won’t be needing a tow anytime soon….at
least because of the transmission!
Picture Source: Library of Congress.
Army Motors, US Army, May, 1940—September,
1945
Book 120, Field Artillery Automotive Instruction, 1941
Edition
TM 10-1103, Willys Model MA, 1941, reprinted by
Post-Era Motor Books, Arcadia, CA 1971
TM 10-1186, Change 1, July 1, 1943 Master Parts
List for Willys Trucks and Trailers Models MA and
MB 1/4 Ton 4x4 Trucks and Model MB-T 1/4 Ton
Trailer
TM 10-1205, American Bantam Maintenance Manual
Model BRC, 1941, reprinted by Post-Era Motor
Books, Arcadia, CA 1971
Eng-Tips Forum, June 2003
TM 10-1348 Change 1, April 10, 1942 Parts List 1/4
Ton 4x4 Model GPW Contract Number 398-QM11424
Fundamentals of Mechanics, Morton C. Mott-Smith,
Ph.D. and Marjorie Van De Water, The Infantry Journal, October, 1944
TM 10-1349 Maintenance Manual for Ford Truck 1/4Ton 4x4, Change 1, May 1, 1943.
Lubrication, Army Motor Maintenance, Text No. 10,
September, 30, 1940
TM 10-585 Automotive Power Transmission Units,
April 10, 1941
Motor Vehicle Maintenance and Engineer Equipment, December, 1945
TM 9-1803B Power Train, Body, and Frame for 1/4Ton 4x4 Truck
New Transmission Case for 1/4-Tons, Army Motors,
December, 1944
TM 9-803 1/4-ton 4x4 Truck (Willys-Overland Model
MB and Ford Model GPW), February, 1944
ORD 8 SNL G503, Truck, 1/4-Ton, 4x4, Command
Reconnaissance (Ford, Model GPW; Willys, Model
MB), Field and Depot Maintenance Allowances
Transmissions, Chapter XX, The Army Motor Mechanic, Quartermaster Depot, Baltimore, MD 1936
ORD 9 SNL G-503, Ordnance Supply Catalog, 15
February, 1945
USMC Motor Vehicle Operators Course, Preventive
Maintenance, Motor Transport School, Camp Lejeune, NC, 1943
Power Transmission Units, Preventive Maintenance
Course for General and Field Officers, September 1,
1942
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TROUBLE SHOOTING AND REBUILDING THE T-84J TRANSMISSION
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INDEX
1941 Willys MB: 11
1942 Ford GPW: 11
717th Airborne Ord. Co.: 15
90 weight: 31
A
Allen socket type screws: 55
American Bantam Car
Company: 21
Amsoil™: 31
Andreasson, John: 2
APO 928: 80
Army Motors: 16, 23, 32, 33,
35, 40, 42, 80
Assemble,
main drive gear: 117
mainshaft 106
Assembly: 103
Atlanta, GA: 15
B
Backlash: 86
Ball bearings: 98
Bantam: 20, 21
Barrow, Robert: 2, 27
Bayes, T/5 Robert E.: 18
BCA 1207SL: 29
BCA 6307S: 29
Bearing,
gear retainer: 51
main drive gear: 29
mainshaft rear: 29
retainer, front, install: 134
Bearings: 29, 98
Before you begin...: 44
BesLube: 31
Book, purpose of: 1
Brass, Al: 2, 66
BRC T-84: 20, 21
Brent Mullins Jeep Parts: 9, 17, 70
Bristol wrench: 45, 55, 127
Bushing,
counter shaft gear: 29
reverse idler: 29
C
Capscrews: 47, 51, 137
Chicago Rawhide 17340: 17, 38,
112
Cleaning: 73
Cleaning the parts: 74
Cluster gear,
install: 105
removal: 65
Cluster shaft tool: 18, 45
Clutch release bearing,
install: 142
spring: 49
Clutching, double: 96
Concerns and sage Advice…: 14
Cork
gasket: 51
seal: 135
Countershaft and idle gearshaft:
93
Countershaft,
gear: 89
install: 120
thrust washers: 99
Cup,
transmission second and
third gear shifter shaft oil
retainer: 38
install: 138
D
Danner, Lt. Leroy M.: 15
Dear Ed.: 15, 80
Details, transmission: 20
Disassemble,
counter shaft gear: 66
main drive gear: 67
mainshaft: 71
synchronizer: 70
Disassembly: 43
Discoloration: 94
Does oil pump from your
transfer case into your
transmission?: 16
Double clutching: 96
Dubois, Arend "Eagle": 2, 7, 23
E
Eagle: 7, 23
“Early” standardized WW2 jeep
T-84J: 23
Ebay: 9
Engine, starting: 10
Eng-Tips™ Forum: 31
Excessive noise: 13
TROUBLE SHOOTING AND REBUILDING THE T-84J TRANSMISSION
F
Final thoughts…: 144
First and reverse,
gear: 85
shifter fork: 100
shifter fork, install: 125
Fitzgerald, Paul: 2, 28
Fitzpatrick, Ron: 2, 9, 18, 45, 55
FM-GPW-7059: 70
FM-GPW-7065: 14
FM-GPW-7080: 14
FM-GPW-7105: 70
FM-GPW-7106: 70
FM-GPW-7107: 70
FM-GPW-7109: 70
FM-GPW-7116: 70
FM-GPW-7208: 132
Ford jeeps refuse to get out of
low gear; 14
Fork,
first and reverse: 100
second and third: 101
Fourroux, Chris: 2, 24, 90, 100,
101
Front thrust washer: 99
G
Gear bearing retainer: 51
Gearshift
housing on case, install:
133
lever, install: 140
Gilmore, Jim: 2, 6, 28, 36, 78, 79
Gopan, Joel: 2, 9, 17, 28, 29, 38,
45, 48, 55, 67, 79, 112, 127, 132,
135, 140
GPW-61720: 14
Grace, Richard: 2, 5, 6, 9, 70, 122
Grammont, Steve: 2
Grease,
leaks into bell housing: 13
pumps into transmission:
14
Guide, Time Schedule: 7
H
Half-Mast, Sgt.: 14
Hard shifting transmission: 13
“heavy duty transmission”: 20, 21
How much time to repair and
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Page 156
replace the transmission: 7
How to double clutch!: 96
HQ 3rd Bn. 126th Ord.: 15
I
Idler,
gear: 91
install: 104
Inspection and repair: 77
Install,
cluster gear: 105
clutch release bearing:
142
countershaft: 120
cup, transmission
second and third gear
shifter shaft oil retainer:
138
first and reverse shifter
fork: 125
front bearing retainer: 134
gearshift housing on case:
133
gearshift lever: 140
idle gear: 104
interlock plunger: 141
internal seal: 112
lock plate: 122
main drive gear assembly:
119
mainshaft assembly: 113
rail guide: 131
second and third shifter
fork: 128
shifter shaft plate and
washer: 132
Interlock,
plunger: 40, 126, 141
install: 141
Internal seal, install 112
84J: 26
Lever, shift: 102
Lewis gear: 66
Lock plate, install: 122
Loss of lubricant: 13
Lt. Leroy M. Danner: 15
Lube equivalents, US and British:
35
Lube specifications: 31
Pre-standardized
BRC T-84 transmission:
21
MA T-84 transmission:
22
Problems, transmission 12
Purpose of this book 2
M
Rail guide, install 131
Ratio 20
Reamer 88
Rear,
thrust washer: 99
washer: 99
Remove,
clutch release bearing: 49
counter shaft: 60
counter shaft and idler
gearshift housing: 46
idle reverse gear: 64
low and reverse, shifter
fork: 55
main drive gear bearing
retainer: 51
mainshaft: 62
shaft lock plate: 59
shifter fork guide rail: 53
second and high, shifter
fork: 55
shifter shafts: 57
Re-peened rivets, transmission
housing: 14
Retainer, gear bearing: 51
Reverse, shifting: 11
Roller bearings: 97
Rowland, Lamar and Jewel: 11,
145
Royall, T/4 Lucian W. Royall: 15
RTV: 17, 141
Main drive
bearing: 29
gear: 81
Main drive gear
assembly, install: 119
bearing rollers: 97
removal: 61
Mainshaft: 84
assembly, install: 113
rear bearing: 29
MB-164742: 14
McCluskey, Mac: 2, 18
Merriam-Webster Online: 31
“Mid” standardized WW2 jeep T84J: 25
Military Maintenance for MB/GPW
jeeps 1941-45: 18
Model T-84J: 20
Monograde gear lube: 32
Motor Transport Officer: 15
Mullins, Brent: 9, 17, 70
Multi-grade gear lube: 32
MVPA rally: 11, 145
N
Japan, US Army Log. Depot 23
Nabholtz, Lawrence: 23, 26
National 494122: 17, 112
NAVDOCKS TP-Tr-9: 7
New Seal to stop lube pumping
from the transfer case: 16
News flash: 14
Noisy T-84J debunked: 4
K
P
Kish, Bill: 2, 99
Kosta, Sgt. Geza: 80
Packing string: 140
Parts diagram and list: 38
Permatex™: 133, 134, 141
Phillips, Thomas and Barbie: 2
Plate, "U" shaped: 12
Portrayal Press: 7
J
L
“Late” standardized WW2 jeep T-
Page 150
R
S
S/Sgt M. W.: 14
Saving a worn case: 36
Scoring: 94
Scrambled jeep synchro-mesh: 41
Screw-Out™, Craftsmen: 55
Second and third shifter fork: 101
install: 128
Second gear 87
Serial No. 169756: 14
TROUBLE SHOOTING AND REBUILDING THE T-84J TRANSMISSION
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Sgt. Half-Mast: 14
Shadetree mechanic: 2
Shift lever: 102
springs rust together: 41
Shift plate reinforcement 13, 80
Shifter plate: 80
trouble: 80
Shifter shaft plate and washer,
install: 132
Shifting:
hard: 13
lower speed in transmission: 10
reverse 11
transmission 10
Slinger, WO-A-410: 14, 17, 108,
109
Snake oil salesmen: 32
Sore as a boil about oil: 33
Spacer, recessed: 38
Specifications, lube: 31
Spence, Dennis: 7
Spring washer: 48
Starting the engine: 10
Starting vehicle: 10
Sticking shift-lever on 1/4-tons: 42
Stopping the vehicle: 11
string, packing: 140
Studebaker: 27
Studio: 2
Synchronizer: 62, 63, 70, 95, 115
T
T/4 Lucian W. Royall: 15
T/5 Robert E. Bayes: 18
T/Sgt. F. W. D.: 14
TB 1803-1: 16
TB 9-1859-8: 7
TC 32: 33
The Jeep Complete: 44
The Military Jeep: 23
The Weasel T-84 transmission: 27
Time Schedule Guide: 7
TM 10-1349: 132
TM 21-305: 96
TM 9-803: 96
TO-19-1A-7: 7
Toledo, Oh: 14
Tool, assemble transmission: 18,
45
Tools, needed: 45
Trail ride: 11
Transmission,
alined: 15
“C” shaped cutout worn:
79
case: 78
control housing assembly,
defect: 15
details: 20
excessive noise: 13
function of: 2
grease leaks into bell
housing: 13
hard shifting: 13
loss of lubricant: 13
new: 16
noise in low gear: 12
oil: 31
parts diagram and list: 38
problems: 12
saving a worn case: 36
scrambled jeep synchromesh: 41
shifter plate: 80
shifting: 10
shifting to lower speed: 10
slips out of gear: 12
slips out of high gear: 12
slips out of second: 12
spring washer: 48
sticking shift-lever on 1/4tons: 42
tools needed: 45
trouble and remedies: 12
variations: 21-27
what it does: 2
Trouble with shifter plates 80
W
“U” shaped plate” 12, 49
“U” shaped washer: 48
US Army Log. Depot, Japan 23
USMC Preventive Maintenance
Manual, 1943: 96
Warner: 20, 66
Washer,
junk 99
rear 99
thrust, front: 99
thrust, rear: 99
wavy: 48, 132
Weasel T-84 transmission, the: 27
What parts do I need to buy?: 6
What the heck is that thing for?:
28
Which vendors should you buy
your parts from?: 9
Why doesn't the lube in some of
the 1/4-ton 4x4x go into the
transmissions?: 14
Willys MA: 22
Wire mainshaft and main driver
gear: 123
WO-635839: 132
WO-635844: 38
WO-635862: 140
WO-636885: 29
WO-637503: 38
WO-637830: 70
WO-637831: 70
WO-637832: 70
WO-637833: 70
WO-637834: 70
WO-637835: 70
WO-A-410: 14, 17
WO-A-738: 16, 38
WO-A-916: 14, 29
WO-A-1379: 140
WO-A-15427: 16, 17, 38, 112
WO-A-15428: 16, 17, 38, 112
www.ebay.com: 9, 45
www.G503.com: 1, 2, 18, 28, 66
www.jcwhitney.com: 45
www.military-media.com: 45
www.northerntool.com: 45
V
Y
Vehicle,
Your jeep jump outta gear?: 40
U
starting: 10
stopping 11
Viscosity, definition: 31
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