Xray XB4C 23 User manual

1
XB4C’23 & XB4D’23
INSTRUCTION MANUAL
FOR XB4C'23 & XB4D'23 EDITION

2
BEFORE YOU START
This is a high-competition, high-quality RC car intended for persons aged 16
years and older with previous experience building and operating RC model
racing cars. This is not a toy; it is a precision racing model. This model racing
car is not intended for use by beginners, inexperienced customers, or by
children without direct supervision of a responsible, knowledgeable adult. If
you DO NOT fulfill these requirements, please return the kit in unused and
unassembled form back to the shop where you have purchased it.
Before building and operating your XRAY, YOU MUST read through all of the
operating instructions and instruction manual and fully understand them to
get the maximum enjoyment and prevent unnecessary damage.
Read carefully and fully understand the instructions before beginning assembly.
Make sure you review this entire manual, download and use set-up book from
the web, and examine all details carefully. If for some reason you decide this is
not what you wanted or expected, DO NOT continue any further. Your hobby
dealer can not accept your kit for return or exchange after it has been partially
or fully assembled.
Contents of the box may differ from pictures. In line with our policy of continuous
product development, the exact specifications of the kit may vary without prior
notice.
SAFETY PRECAUTIONS
Contains:
LEAD (CAS 7439-92-1) ANTIMONY (CAS 7440-36-0)
WARNING: This product contains a chemical known to the state of California
to cause cancer and birth defects or other reproductive harm.
CAUTION: CANCER HAZARD
Contains lead, a listed carcinogen. Lead is harmful if ingested. Wash
thoroughly after using. DO NOT use product while eating, drinking or using
tobacco products. May cause chronic effects to gastrointestinal tract, CNS,
kidneys, and blood. MAY CAUSE BIRTH DEFECTS.
When building, using and/or operating this model always wear protective
glasses and gloves.
Take appropriate safety precautions prior to operating this model. You are
responsible for this model‘s assembly and safe operation! Please read the
instruction manual before building and operating this model and follow all
safety precautions. Always keep the instruction manual at hand for quick
reference, even after completing the assembly. Use only genuine and original
authentic XRAY parts for maximum performance. Using any third party parts
on this model will void guaranty immediately.
Improper operation may cause personal and/or property damage. XRAY
and its distributors have no control over damage resulting from shipping,
improper construction, or improper usage. XRAY assumes and accepts no
responsibility for personal and/or property damages resulting from the use
of improper building materials, equipment and operations. By purchasing
any item produced by XRAY, the buyer expressly warrants that he/she is in
compliance with all applicable federal, state and local laws and regulation
regarding the purchase, ownership and use of the item. The buyer expressly
agrees to indemnify and hold harmless XRAY for all claims resulting directly
or indirectly from the purchase, ownership or use of the product. By the act
of assembling or operating this product, the user accepts all resulting liability.
If the buyer is not prepared to accept this liability, then he/she should return
this kit in new, unassembled, and unused condition to the place of purchase.
IMPORTANT NOTES – GENERAL
• This product is not suitable for children under 16 years of age without the
direct supervision of a responsible and knowledgeable adult.
• Carefully read all manufacturers warnings and cautions for any parts used
in the construction and use of your model.
• Assemble this kit only in places away from the reach of very small children.
• First-time builders and users should seek advice from people who have
building experience in order to assemble the model correctly and to allow
the model to reach its performance potential.
• Exercise care when using tools and sharp instruments.
• Take care when building, as some parts may have sharp edges.
• Keep small parts out of reach of small children. Children must not be
allowed to put any parts in their mouth, or pull vinyl bag over their head.
• Read and follow instructions supplied with paints and/or cement, if used
(not included in kit).
• Immediately after using your model, DO NOT touch equipment on the
model such as the motor and speed controller, because they generate high
temperatures. You may seriously burn yourself seriously touching them.
• Follow the operating instructions for the radio equipment at all times.
• DO NOT put fingers or any objects inside rotating and moving parts, as this
may cause damage or serious injury as your finger, hair, clothes, etc. may
get caught.
• Be sure that your operating frequency is clear before turning on or running
your model, and never share the same frequency with somebody else at the
same time. Ensure that others are aware of the operating frequency you
are using and when you are using it.
• Use a transmitter designed for ground use with RC cars. Make sure that no
one else is using the same frequency as yours in your operating area. Using
the same frequency at the same time, whether it is driving, flying or sailing,
can cause loss of control of the RC model, resulting in a serious accident.
• Always turn on your transmitter before you turn on the receiver in the car.
Always turn off the receiver before turning your transmitter off.
• Keep the wheels of the model off the ground when checking the operation
of the radio equipment.
• Disconnect the battery pack before storing your model.
• When learning to operate your model, go to an area that has no obstacles
that can damage your model if your model suffers a collision.
• Remove any sand, mud, dirt, grass or water before putting your model
away.
• If the model behaves strangely, immediately stop the model, check and
clear the problem.
• To prevent any serious personal injury and/or damage to property, be
responsible when operating all remote controlled models.
• The model car is not intended for use on public places and roads or areas
where its operation can conflict with or disrupt pedestrian or vehicular traffic.
• Because the model car is controlled by radio, it is subject to radio
interference from many sources that are beyond your control. Since radio
interference can cause momentary loss of control, always allow a safety
margin in all directions around the model in order to prevent collisions.
• DO NOT use your model:
- Near real cars, animals, or people that are unaware that an RC car is being
driven.
- In places where children and people gather
- In residential districts and parks
- In limited indoor spaces
- In wet conditions
- In the street
- In areas where loud noises can disturb others, such as hospitals and
residential areas.
- At night or anytime your line of sight to the model may be obstructed or
impaired in any way.
To prevent any serious personal injury and/or damage to property, please be
responsible when operating all remote controlled models.
CUSTOMER SUPPORT
XRAY Europe
K Vystavisku 6992
91101 Trenčín
Slovakia, EUROPE
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]
We have made every effort to make these instructions as easy to understand as
possible. However, if you have any difficulties, problems, or questions, please DO
NOT hesitate to contact the XRAY support team at [e-mail]. Also, please
visit our Web site at www.teamxray.com to find the latest updates, set-up information,
option parts, and many other goodies. We pride ourselves on taking excellent care
of our customers.
You can join thousands of XRAY fans and enthusiasts in our online community at:
www.teamxray.com
XRAY USA
RC America, 2030 Century Center Blvd #15
Irving, TX 75062
USA
Phone: [phone]
Fax: [phone]
E-mail: [email protected]
FAILURE TO FOLLOW THESE INSTRUCTIONS WILL BE CONSIDERED AS ABUSE AND/OR NEGLECT.

3
IMPORTANT NOTES – ELECTRICAL
• Insulate any exposed electrical wiring (using heat shrink tubing or electrical
tape) to prevent dangerous short circuits. Take maximum care in wiring,
connecting and insulating cables. Make sure cables are always connected
securely. Check connectors for if they become loose. And if so, reconnect
them securely. Never use RC models with damaged wires. A damaged wire
is extremely dangerous, and can cause short-circuits resulting in fire. Please
have wires repaired at your local hobby shop.
• Low battery power will result in loss of control. Loss of control can occur due
to a weak battery in either the transmitter or the receiver. Weak running
battery may also result in an out of control car if your car‘s receiver power is
supplied by the running battery. Stop operation immediately if the car starts
to slow down.
• When not using RC model, always disconnect and remove battery.
• DO NOT disassemble battery or cut battery cables. If the running battery
short-circuits, approximately 300W of electricity can be discharged, leading
to fire or burns. Never disassemble battery or cut battery cables.
• Use a recommended charger for the receiver and transmitter batteries
and follow the instructions correctly. Over-charging, incorrect charging,
or using inferior chargers can cause the batteries to become dangerously
hot. Recharge battery when necessary. Continual recharging may damage
battery and, in the worst case, could build up heat leading to fire. If battery
becomes extremely hot during recharging, please ask your local hobby
shop for check and/or repair and/or replacement.
• Regularly check the charger for potential hazards such as damage to the
cable, plug, casing or other defects. Ensure that any damage is rectified
before using the charger again. Modifying the charger may cause short-
circuit or overcharging leading to a serious accident. Therefore DO NOT
modify the charger.
• Always unplug charger when recharging is finished.
• DO NOT recharge battery while battery is still warm. After use, battery
retains heat. Wait until it cools down before charging.
• DO NOT allow any metal part to short circuit the receiver batteries or other
electrical/electronic device on the model.
• Immediately stop running if your RC model gets wet as may cause short
circuit.
• Please dispose of batteries responsibly. Never put batteries into fire.
XRAY guarantees this model kit to be free from defects in both material and
workmanship within 30 days of purchase. The total monetary value under
warranty will in no case exceed the cost of the original kit purchased. This
warranty does not cover any components damaged by use or modification
or as a result of wear. Part or parts missing from this kit must be reported
within 30 days of purchase. No part or parts will be sent under warranty
without proof of purchase. Should you find a defective or missing part, contact
the local distributor. Service and customer support will be provided through
local hobby store where you have purchased the kit, therefore make sure to
purchase any XRAY products at your local hobby store. This model racing car
is considered to be a high-performance racing vehicle. As such this vehicle
will be used in an extreme range of conditions and situations, all which may
cause premature wear or failure of any component. XRAY has no control over
usage of vehicles once they leave the dealer, therefore XRAY can only offer
warranty against all manufacturer‘s defects in materials, workmanship, and
assembly at point of sale and before use. No warranties are expressed or
implied that cover damage caused by what is considered normal use, or cover
or imply how long any model cars‘ components or electronic components will
last before requiring replacement.
Due to the high performance level of this model car you will need to
periodically maintain and replace consumable components. Any and all
warranty coverage will not cover replacement of any part or component
damaged by neglect, abuse, or improper or unreasonable use. This includes
but is not limited to damage from crashing, chemical and/or water damage,
excessive moisture, improper or no maintenance, or user modifications which
compromise the integrity of components. Warranty will not cover components
that are considered consumable on RC vehicles. XRAY does not pay nor refund
shipping on any component sent to XRAY or its distributors for warranty. XRAY
reserves the right to make the final determination of the warranty status of
any component or part.
Limitations of Liability
XRAY makes no other warranties expressed or implied. XRAY shall not be liable
for any loss, injury or damages, whether direct, indirect, special, incidental,
or consequential, arising from the use, misuse, or abuse of this product and/
or any product or accessory required to operate this product. In no case shall
XRAY‘s liability excess the monetary value of this product.
Take adequate safety precautions prior to operating this model. You
are responsible for this model’s assembly and safe operation.
Disregard of the any of the above cautions may lead to accidents,
personal injury, or property damage. XRAY MODEL RACING CARS
assumes no responsibility for any injury, damage, or misuse of this
product during assembly or operation, nor any addictions that may
arise from the use of this product.
All rights reserved.
QUALITY CERTIFICATE
XRAY MODEL RACING CARS uses only the highest quality materials, the
best compounds for molded parts and the most sophisticated manufacturing
processes of TQM (Total Quality Management). We guarantee that all parts
of a newly-purchased kit are manufactured with the highest regard to quality.
However, due to the many factors inherent in model racecar competition, we
cannot guarantee any parts once you start racing the car. Products which have
been worn out, abused, neglected or improperly operated will not be covered
under warranty.
We wish you enjoyment of this high-quality and high-performance RC car and
wish you best success on the track!
In line with our policy of continuous product development, the exact specifications of the kit may
vary. In the unlikely event of any problems with your new kit, you should contact the model shop
where you purchased it, quoting the part number.
We do reserve all rights to change any specification without prior notice. All rights reserved.
R/C & BUILDING TIPS
• Make sure all fasteners are properly tightened. Check them periodically.
• Make sure that chassis screws DO NOT protrude from the chassis.
• For the best performance, it is very important that great care is taken to
ensure the free movement of all parts.
• Clean all ball-bearings so they move very easily and freely.
• Tap or pre-thread the plastic parts when threading screws.
• Self-tapping screws cut threads into the parts when being tightened. DO
NOT use excessive force when tightening the self-tapping screws because
you may strip out the thread in the plastic. We recommended you stop
tightening a screw when you feel some resistance.
• Ask your local hobby shop for any advice.
Please support your local hobby shop. We at XRAY Model Racing Cars support
all local hobby dealers. Therefore we ask you, if at all possible, to purchase
XRAY products at your hobby dealer and give them your support like we do.
If you have difficulty finding XRAY products, please check out www.teamxray.
com to get advice, or contact us via email at [e-mail], or contact
the XRAY distributor in your country.
WARRANTY

4
TOOLS REQUIRED
EQUIPMENT REQUIRED
EQUIPMENT INCLUDED
(HUDY #106210)
Premium
Graphite Grease
Transmitter Steering ServoReceiver
Lexan™ PaintBattery Charger 4x Tires & Inserts
Speed Controller LiPo BatteryElectric Motor & Pinion Gear
with Setscrew
Double-sided Tape
(HUDY #107875)
Tweezer
Allen 1.5mm (#111545 - HUDY EXCLUSIVE Limited Edition)
Allen 2.0mm (#112045 - HUDY EXCLUSIVE Limited Edition)
Socket 5.5mm (#175535 - HUDY EXCLUSIVE Limited Edition)
Socket 7.0mm (#177035 - HUDY EXCLUSIVE Limited Edition)
Arm Reamer 3.0mm (#107643 - HUDY EXCLUSIVE Limited Edition)
Reamer (#107602 - HUDY EXCLUSIVE Limited Edition)
Turnbuckle Wrench 3mm (HUDY #181030)
Special Tool for turnbuckles, nuts (HUDY #181090)
TL
CA
Pocket Hobby Knife (HUDY #188981)
Scissors (HUDY #188990)
Side Cutters
(HUDY #189010)
Combination Pliers
(HUDY #189020)
Professional Multi Tool
(HUDY #183011)
OILOILOIL
OILOILOILOIL
CA glueThreadlock
Bearing Oil
(HUDY #106230)
OIL
700cSt (#106370)
HUDY Premium
Silicone Oils
* Kit includes smaller but sufficient amount of oil and grease to build the car.
550cSt (#106355)
HUDY Premium
Silicone Oils
10.000cSt (#106510)
HUDY Premium
Silicone Oils
600cSt (#106360)
HUDY Premium
Silicone Oils
500cSt (#106350)
HUDY Premium
Silicone Oils
7.000cSt (#106470)
HUDY Premium
Silicone Oils
100.000cSt (#106610)
HUDY Premium
Silicone Oils
DIRT DIRT DIRT DIRT DIRT
CARPET CARPET CARPET CARPET

TECH TIPS
Fine sandpaper
Use fine sandpaper to
sand smooth the edges of
all graphite parts.
Apply CA glue to all edges
of the graphite parts.
DRIVE SHAFT PIN SERVICING
TIP
To enjoy the longest possible lifespan of the drive shafts and diff outdrives, it is extremely important to properly service the drive shaft pins.
Inspect the pins after every 3 hours of runtime. If the pins show any wear, replace them with new pins.
To replace the worn pins use only
premium HUDY drive pins
(#106053 2.5mm dia x 10mm lenght).
GRAPHITE PARTS PREPARATION
TIP
Follow this Tech Tip to prepare the graphite parts. Sand the edges with sandpaper, and then seal the edges with CA glue to reinforce them and help prevent delamination.
Prepare all Graphite Parts:
• Front shock tower
• Rear shock tower
DO NOT use drive shafts
when the pins are worn.
Press out the worn pins.
Press in new pins and
regularly inspect for wear.
At the beginning of each section is an exploded view of the parts to be assembled. There is also a list of all
the parts and part numbers that are related to the assembly of that section.
The part descriptions are color-coded to make it easier for you to identify the source of a part. Here are
what the different colors mean:
STYLE A - indicates parts that are included in the bag marked for the section.
STYLE B - indicates parts that are included in the box.
STYLE C - indicates parts that are already assembled from previous steps.
COLOR INDICATIONS
361112
364903
364912
For quick & easy drive pin replacements use
#106000 HUDY Drive Pin Replacement Tool
together with #106036 Ejector Pivot Pin &
Alternating Pivot 2.5mm.
NOT INCLUDED
To ensure that you always have access to the most up-to-date version of the Set-up
Book you can download the HUDY Set-up Book from their web site at [www.hudy.
net] By offering this online version instead of including a hardcopy printed version
in kits, you will always be assured of having the most current updated version.
XRAY offers wide range of optional tuning parts which are
listed in a table like this. Please refer to the exploded view
of each main section to verify which part is included in the kit
while all other parts are available only as an optional part
and must be purchased separately.
SAMPLE OF OPTIONAL PARTS
#36XXXX TYPE1 OPTION 1
#36XXXX TYPE1 OPTION 2
#36XXXX TYPE1 INCLUDED
Follow Set-Up Book:
5
MANUAL STEPS ONLY FOR DIRT MANUAL STEPS ONLY FOR CARPET MANUAL DUAL STEPS FOR CARPET AND DIRT
1. BALL DIFFERENTIAL 1. GEAR DIFFERENTIAL
BAG BAG
3. REAR DRIVETRAIN
DIRTDIRT CARPETCARPET

BEVEL & SATELITTE GEARS + PINS
#304932 + #304980 GRAPHITE INCLUDED
#335030 + #335080 STEEL OPTION
6
1. FRONT & REAR DIFFERENTIAL
2x
2x
STEP DETAIL
STEP DETAIL
Use tweezers to
insert pin.
➊
➊
➋
➋
➌
➌
➍
➍
➍
➎
➎
➎
➍➎
➍
304932 GRAPHITE GEAR DIFF BEVEL & SATELLITE GEARS (2+4)
304980 COMPOSITE GEAR DIFF CROSS PIN
304990 DIFF GASKET (4)
364903 GEAR DIFFERENTIAL - LARGE VOLUME - SET
364912 COMPOSITE GEAR DIFFERENTIAL CASE - LARGE VOLUME
364920 COMPOSITE GEAR DIFFERENTIAL COVER - LARGE VOLUME
364940 STEEL DIFFERENTIAL BEVEL GEAR FOR LARGE VOLUME DIFF 40T
BAG
364962
364912
964050
964031
971050
364920
903258
364962
304932
304932
941014
981210
971050
964031
964031
964050
304990
364940
981210
941014
304932
304980
971050
O 5x1.5
971050
O 5x1.5
964050
S 5x15x0.3
964050
S 5x15x0.3
981210
P 2x10
981210
P 2x10
NOTE ORIENTATION
OIL
OIL
DETAIL
#106210 HUDY GRAPHITE GREASE
Cut off remaining
material
#106210 HUDY GRAPHITE GREASE
364962 GEAR DIFF OUTDRIVE ADAPTER FOR LARGE VOLUME DIFF (2)
903258 HEX SCREW SFH M2.5x8 (10)
941014 BALL-BEARING 10x15x4 RUBBER SEALED - GREASE (2)
964031 WASHER S 3.5x10x0.2 (10)
964050 WASHER S 5x15x0.3 (10)
971050 SILICONE O-RING 5x1.5 (10)
981210 PIN 2x10 (10)
NOTE ORIENTATION
#364912-G
GEAR DIFFERENTIAL CASE - LARGE
VOLUME - GRAPHITE
#364920-G
GEAR DIFFERENTIAL COVER - LARGE
VOLUME - GRAPHITE
#364941
STEEL DIFFERENTIAL BEVEL GEAR
FOR LARGE VOLUME DIFF 41T
#365100
XRAY XB4 ACTIVE DIFFERENTIAL
FRONT/REAR - SET
ACTIVE DIFF SEGMENTS
#325123 60º OPTION
#325125 90º INCLUDED
#325127 120º OPTION
DIRTCARPET

DIFFERENTIAL OIL
Fill differential up to the top of the diff
cross-pins. DO NOT fill the diff to the top
of the housing.
TO ENSURE YOU HAVE THE SAME AMOUNT OF OIL FROM REBUILD TO REBUILD, DO THE FOLLOWING:
➊ Put the diff (without oil) on the scale and check the
weight (approximately 11.47g)
➋ Slowly pour oil into the diff and watch the weight. Add
1.60g of oil into the diff. The approximate weight of the diff
including oil is 13.07g.
LOW TRACTION 7.000cSt (HUDY #106470)
MEDIUM-HIGH TRACTION 10.000cSt (HUDY #106510)
SUPER-HIGH TRACTION 15.000cSt (HUDY #106515)
NOTE:
Softer oil increases rear traction, harder oil increases on-power steering.
LOW TRACTION 7.000cSt (HUDY #106470)
MEDIUM-HIGH TRACTION 10.000cSt (HUDY #106510)
SUPER-HIGH TRACTION 15.000cSt (HUDY #106515)
NOTE:
Softer oil increases steering, harder oil increases stability.
TIPS FOR DIFFERENTIALS
REAR DIFERENTIALFRONT DIFERENTIAL
11.47g + 1.60g = 13.07g
#107865
HUDY Ultimate Digital Pocket
Scale 300g±0.01g
Tighten the screws equally but DO NOT
tighten them completely.
Finish tightening in
this order.
g
1 1.47 g
1 3 07
7
1. FRONT & REAR DIFFERENTIAL
➊
➊
➋
➋
➌
➌
➍
➍
964031
S 3.5x10x0.2
903258
SFH M2.5x8
941014
BB 10x15x4
2x 2x 2x
Front diff Silicone oil
10.000cSt
7.000cSt
Fill just above the cross-pins.
Rear diff Silicone oil
10.000cSt
7.000cSt
Fill just above the cross-pins.
OIL
PROPER AMOUNT OF OIL IN THE DIFFS
Use a digital scale to measure the exact
amount of oil in the diff. Remember that
during operation the diff gets hotter and the
heat may allow the oil to expand. If there is
too much oil inside it may interfere with the
diff operation and damage the internal gears.
Use HUDY Ball-Bearing Grease
#106220 - STANDARD
#106221 - BLUE
#106222 - RED
DIRTCARPET
DIRT DIRT
CARPET CARPET

8
BAG
STEP DETAIL
➊
➋
➌
➍➍➎
OIL
OIL
964050
S 5x15x0.3
980210
P 2x10
DETAIL
➍
➎
1. CENTER GEAR DIFFERENTIAL
304990
964050
971050
903258
364981
364963
364912
980210
364963
971050
304930
364913
980210
902306
STEP DETAIL
Use tweezers to
insert pin. ➊
➋
➌
➍
➎
➍
NOTE ORIENTATION
OIL
#106210 HUDY GRAPHITE GREASE
971050
O 5x1.5
971050
O 5x1.5
964050
S 5x15x0.3
980210
P 2x10
304930
964031
304980
#364912-G
GEAR DIFFERENTIAL CASE - LARGE
VOLUME - GRAPHITE
LONG
LONG
SHORT
SHORT
BEVEL & SATELITTE GEARS
#304930 COMPOSITE INCLUDED
#304932 GRAPHITE OPTION
#335030 STEEL OPTION
CENTER DIFF SPUR GEARS
#364978 78T/48 OPTION
#364981 81T/48 INCLUDED
304930 COMPOSITE GEAR DIFF BEVEL & SATELLITE GEARS (2+4)
304980 COMPOSITE GEAR DIFF CROSS PIN
304990 DIFF GASKET (4)
364904 GEAR CENTER DIFFERENTIAL - LARGE VOLUME - SET
364912 COMPOSITE GEAR DIFFERENTIAL CASE - LARGE VOLUME
364913 COMPOSITE CENTER GEAR DIFF ADAPTER - LARGE VOLUME
364963 CENTER GEAR DIFF OUTDRIVE ADAPTER FOR LARGE VOLUME DIFF (1+1)
364981 COMPOSITE CENTER DIFF SPUR GEAR 81T / 48
902306 HEX SCREW SH M3x6 (10)
903258 HEX SCREW SFH M2.5x8 (10)
964031 WASHER S 3.5x10x0.2 (10)
964050 WASHER S 5x15x0.3 (10)
971050 SILICONE O-RING 5x1.5 (10)
980210 PIN 2x10 (10)
GEAR DIFF CROSS PINS
#304980 COMPOSITE INCLUDED
#335080 STEEL OPTION
DIRT
#365101 XRAY XB4 ACTIVE
DIFFERENTIAL - CENTER - SET
ACTIVE DIFF SEGMENTS
#325123 60º OPTION
#325125 90º INCLUDED
#325127 120º OPTION

9
DIFFERENTIAL OIL
TO ENSURE YOU HAVE THE SAME AMOUNT OF OIL FROM REBUILD TO REBUILD, DO THE FOLLOWING:
➊ Put the diff (without oil) on the scale and
check the weight (approximately 11.72g)
➋ Slowly pour oil into the diff and watch the weight.
LOW TRACTION 50.000cSt (HUDY #106550)
MEDIUM TRACTION 100.000cSt (HUDY #106610)
HIGH TRACTION 500.000cSt (HUDY #106650)
NOTE:
Softer oil increases steering, harder oil increases stability.
FOR CENTER DIFFERENTIAL
#107865
HUDY Ultimate Digital Pocket
Scale 300g±0.01g
g
1 1.72 g
13 22
11.72g + 1.50g = 13.22gDiff.
100.000cSt
Fill differential up to the top of the
diff cross-pins. DO NOT fill the diff
to the top of the housing.
1. CENTER GEAR DIFFERENTIAL
902306
SH M3x6
903258
SFH M2.5x8
➊
➋
➌
➍
Finish tightening in this order.
Tighten the screws equally but DO NOT
tighten them completely.
964031
S 3.5x10x0.2
PROPER AMOUNT OF OIL IN THE DIFFS
Use a digital scale to measure the exact amount
of oil in the diff. Remember that during operation
the diff gets hotter and the heat may allow the oil
to expand. If there is too much oil inside it may
interfere with the diff operation and damage the
internal gears.
Center diff
Silicone oil 100.000cSt
Fill just above the cross-pins.
OIL
DIRT

2. REAR CENTRAL TRANSMISSION DIRTCARPET
10
324172 COMPOSITE ADJUSTMENT BALL-BEARING HUB (2)
362006 DIFF BULKHEAD - HORIZONTAL SPLIT DESIGN (HS) - FRONT/REAR - SET
362370 INLINE HUB FOR BEVEL DRIVE GEAR - REAR HS BULKHEAD - 1+2+3 DOTS
363085 GRAPHITE SHOCK TOWER FOR HS BULKHEAD - REAR - 3.5MM
365127 STEEL BEVEL DRIVE GEAR - FOR HS BULKHEAD - CNC-MACHINED - 16T
365444 CENTRAL DOGBONE SHAFT UNIVERSAL JOINT - HUDY SPRING STEEL™
BAG
362006
902305
940815
362370
324172
940510
981208
902312
364903+364940
365127
362006
365444
363085
902310
XRAY BALL-BEARINGS
#359050 5x10x4 GREASE OPTION
#940510 5x10x4 OIL INCLUDED
#940814 8x14x4 GREASE OPTION
#940815 8x14x4 OIL INCLUDED
902305 HEX SCREW SH M3x5 (10)
902310 HEX SCREW SH M3x10 (10)
902312 HEX SCREW SH M3x12 (10)
940510 BALL-BEARING 5x10x4 RUBBER SEALED - OIL (2)
940815 BALL-BEARING 8x14x4 RUBBER SEALED - OIL (2)
981208 PIN 2x8 (10)
364903 GEAR DIFFERENTIAL - LARGE VOLUME - SET
364940 STEEL DIFFERENTIAL BEVEL GEAR FOR LARGE VOLUME DIFF 40T
#365100
XRAY XB4 ACTIVE DIFFERENTIAL
FRONT/REAR - SET
ACTIVE DIFF SEGMENTS
#325123 60º OPTION
#325125 90º INCLUDED
#325127 120º OPTION
INLINE HUBS - REAR
#362370 1 DOT OPTION
#362370 2 DOTS OPTION
#362370 3 DOTS INCLUDED
BALL-BEARING HUBS
#324172 1 DOT OPTION
#324172 2 DOTS OPTION
#324172 3 DOTS INCLUDED

2. REAR CENTRAL TRANSMISSION CARPET
11
940510
BB 5x10x4
940815
BB 8x14x4
902312
SH M3x12
902305
SH M3x5
902310
SH M3x10
981208
P 2x8
NOTE ORIENTATION
DETAIL
➊
➋
➌
➍
➎
➏
Bearing with BLUE
rubber covers
GRAPHITE GREASE
(HUDY #106210)
8x14x4mm
OIL
5x10x4mm
OIL
Bearing Oil
(HUDY #106230)
Follow the TECH TIP on page 5
to prepare graphite parts.
NOTE ORIENTATION
DOTS must have same orientation
on each side (dots up or down).
HIGHEST
Bevel & Differential
3 DOTS
3 DOTS
3 DOTS
HIGHEST
HIGHEST
HIGHEST
BEVEL DRIVE GEAR & DIFFERENTIAL
HEIGHT ADJUSTMENT
INITIAL SETTING
INITIAL SETTING
INITIAL SETTING
CARPET
NOTE DIFF
ORIENTATION
NOTE
ORIENTATION
NOTE ORIENTATION
EXTREME WARNING
3 DOTS=3 DOTS

12
2. REAR CENTRAL TRANSMISSION DIRT
940510
BB 5x10x4
940815
BB 8x14x4
902312
SH M3x12
902305
SH M3x5
902310
SH M3x10
981208
P 2x8
➊
➋
➌
➍
➎
➏
Bearing with BLUE
rubber covers
GRAPHITE GREASE
(HUDY #106210)
8x14x4mm
OIL
5x10x4mm
OIL
Bearing Oil
(HUDY #106230)
Follow the TECH TIP on page 5
to prepare graphite parts.
NOTE ORIENTATION
DOTS must have same orientation
on each side (dots up or down).
LOWEST
Bevel & Differential
DIRT
REAR BEVEL DRIVE GEAR
& DIFFERENTIAL
HEIGHT ADJUSTMENT INITIAL SETTING
INITIAL SETTING
INITIAL SETTING
3 DOTS 3 DOTS
LOWEST 3 DOTS
LOWEST
LOWEST
NOTE DIFF
ORIENTATION
NOTE
ORIENTATION
NOTE ORIENTATION
DETAIL
EXTREME WARNING
3 DOTS=3 DOTS
NOTE ORIENTATION

2. FRONT CENTRAL TRANSMISSION DIRTCARPET
XRAY BALL-BEARINGS
#359050 5x10x4 GREASE OPTION
#940510 5x10x4 OIL INCLUDED
#940814 8x14x4 GREASE OPTION
#940815 8x14x4 OIL INCLUDED
13
324172 COMPOSITE ADJUSTMENT BALL-BEARING HUB (2)
362006 DIFF BULKHEAD BLOCK SET
362086 GRAPHITE SHOCK TOWER FOR HS BULKHEAD - FRONT - 3.5MM
362371 ANGLED HUB FOR BEVEL DRIVE GEAR - FRONT HS BULKHEAD - 1 DOT
362373 ANGLED HUB FOR BEVEL DRIVE GEAR - FRONT HS BULKHEAD - 3 DOTS
365127 STEEL BEVEL DRIVE GEAR - FOR HS BULKHEAD - CNC-MACHINED - 16T
365444 CENTRAL DOGBONE SHAFT UNIVERSAL JOINT - HUDY SPRING STEEL™
902305 HEX SCREW SH M3x5 (10)
902310 HEX SCREW SH M3x10 (10)
902312 HEX SCREW SH M3x12 (10)
940510 BALL-BEARING 5x10x4 RUBBER SEALED - OIL (2)
940815 BALL-BEARING 8x14x4 RUBBER SEALED - OIL (2)
981208 PIN 2x8 (10)
364903 GEAR DIFFERENTIAL - LARGE VOLUME - SET
364940 STEEL DIFFERENTIAL BEVEL GEAR FOR LARGE VOLUME DIFF 40T
BAG
981208
940815
362371
362373 902305
362086
362006
902310
902312
365444
940510
324172
365127
362006
364903+364940
DIRT
CARPET
#365100
XRAY XB4 ACTIVE DIFFERENTIAL
FRONT/REAR - SET
ACTIVE DIFF SEGMENTS
#325123 60º OPTION
#325125 90º INCLUDED
#325127 120º OPTION
ANGLE HUBS - FRONT
#362371 1 DOT INCLUDED
#362372 2 DOTS OPTION
#362373 3 DOTS INCLUDED
BALL-BEARING HUBS
#324172 1 DOT INCLUDED
#324172 2 DOTS OPTION
#324172 3 DOTS INCLUDED

14
2. FRONT CENTRAL TRANSMISSION CARPET
940510
BB 5x10x4
940815
BB 8x14x4
902310
SH M3x10
981208
P 2x8
Follow the TECH TIP on page 5
to prepare graphite parts.
902305
SH M3x5
902312
SH M3x12
➊
➋
➌
➍
➎
➏
Bearing with BLUE
rubber covers THREAD LOCK
GRAPHITE GREASE
(HUDY #106210)
8x14x4mm
OIL
OIL
Bearing Oil
(HUDY #106230)
5x10x4mm
NOTE ORIENTATION
DETAIL
REAR BEVEL DRIVE GEAR
& DIFFERENTIAL
HEIGHT ADJUSTMENT
CARPET
NOTE
ORIENTATION
NOTE ORIENTATION
DETAIL
EXTREME
WARNING
1 DOT
1 DOT
1 DOT=1 DOT
1 DOT
ANGLED HUB
ANGLED HUB
MIDDLE DOWN
INITIAL SETTING
BEVEL GEAR ADJ.
INITIAL SETTING
DIFF HEIGHT ADJ.
NOTE ORIENTATION
THESE POSITIONS WILL DESTROY THE GEARS.
NEVER USE THESE POSITIONS !!!
HIGHEST HIGHER MIDDLE UP
NOTE ORIENTATION
DOTS must have same orientation
on each side (dots up or down).
NOTE DIFF
ORIENTATION

15
2. FRONT CENTRAL TRANSMISSION DIRT
940510
BB 5x10x4
940815
BB 8x14x4
902310
SH M3x10
981208
P 2x8
Follow the TECH TIP on page 5
to prepare graphite parts.
902305
SH M3x5
902312
SH M3x12
➊
➋
➌
➍
➎
➏
Bearing with BLUE
rubber covers THREAD LOCK
GRAPHITE GREASE
(HUDY #106210)
8x14x4mm
OIL
OIL
Bearing Oil
(HUDY #106230)
5x10x4mm
NOTE ORIENTATION
DETAIL
REAR BEVEL DRIVE GEAR
& DIFFERENTIAL
HEIGHT ADJUSTMENT
DIRT
NOTE DIFF
ORIENTATION
NOTE ORIENTATION
DOTS must have same orientation
on each side (dots up or down).
NOTE
ORIENTATION
NOTE ORIENTATION
DETAIL
EXTREME
WARNING
3 DOTS
3 DOTS
3 DOTS=3 DOTS
3 DOTS
ANGLED HUB
ANGLED HUB
LOWEST
NOTE ORIENTATION
THESE POSITIONS WILL DESTROY THE GEARS.
NEVER USE THESE POSITIONS !!!
HIGHEST HIGHER MIDDLE UP
INITIAL SETTING
BEVEL GEAR ADJ.
INITIAL SETTING
DIFF HEIGHT ADJ.

DIRTCARPET
16
3. REAR SUSPENSION
363113-H
363123-H
363325
367210
362315
362478
362473
363316
903312
902308
362006
903312
362315
901304
901303
303431-K
303454
901308
303454
303431-K ALU 4.9MM BALL END - BLACK (2)
303454 BALL JOINT 4.9MM - OPEN (4)
362006 DIFF BULKHEAD BLOCK SET
362315 ECCENTRIC BUSHING SET (2)
362473 ANTI-ROLL BAR 1.3 MM
362478 ANTI-ROLL BAR 1.8 MM
363113-H COMPOSITE LONG SUSPENSION ARM REAR LOWER RIGHT - HARD
363123-H COMPOSITE LONG SUSPENSION ARM REAR LOWER LEFT - HARD
363316 ALU SUSPENSION HOLDER FOR HS BULKHEAD - REAR-FRONT
BAG
Remove the 3x6.5x2mm
shim from each rear arm.
ANTI-ROLL BARS
#362470 1.0mm
OPTION
#362471 1.1mm OPTION
#362472 1.2mm OPTION
#362473 1.3mm INCLUDED
#362474 1.4mm OPTION
#362476 1.6mm OPTION
#362478 1.8mm INCLUDED
#362480 2.0mm OPTION
363325 ALU SUSPENSION HOLDER 2° FOR HS BULKHEAD - REAR-REAR
367210 SUSPENSION PIVOT PIN (2)
901303 HEX SCREW SB M3x3 (10)
901304 HEX SCREW SB M3x4 (10)
901308 HEX SCREW SB M3x8 (10)
902308 HEX SCREW SH M3x8 (10)
903312 HEX SCREW SFH M3x12 (10))
SHORT REAR SUSPENSION ARMS
#363112-H RIGHT HARD OPTION
#363122-H LEFT HARD OPTION
#363112-G RIGHT GRAPHITE OPTION
#363122-G LEFT GRAPHITE OPTION
LONG REAR SUSPENSION ARMS
#363113-H RIGHT HARD INCLUDED
#363123-H LEFT HARD INCLUDED
#363113-G RIGHT GRAPHITE OPTION
#363123-G LEFT GRAPHITE OPTION
#363326
ALU LOWER SUSPENSION HOLDER WIDE
FOR HS BULKHEAD - RR
#363317
ALU LOWER SUSPENS. HOLDER WIDE
FOR HS BULKHEAD - RF
363113-H (LONG)
363123-H (LONG)
DIRT
CARPET

TOE-IN
ANTI-SQUAT
ROLL CENTER
TRACK-WIDTH
3. REAR SUSPENSION DIRTCARPET
ECCENTRIC BUSHINGS HAVE TWO DIFFERENT OFFSETS FROM THE CENTER.
Middle position = 0.5° or 0.375mm from center. Outer position = 1° or 0.75mm from center.
The XRAY rear alu lower suspension holders provide great range of adjustment for the rear suspension. Using different combinations of eccentric bushings, fine adjustment of rear anti-squat, rear toe-in, rear
roll center, and rear track-width can be obtained. For more information about the influence of rear anti-squat, rear toe-in, rear roll center and rear track width on car handling, please refer to HUDY Set-up Book
(#209100).
The tables describe the amounts of adjustment using the center and outside positions of the eccentric bushings.
The middle position eccentric bushings allow for finer adjustment increments.
The track-width is directly influenced by the size of
the wheels and tires used.
ANTI-SQUAT ROLL CENTER TRACK-WIDTH TOE-IN
RR RR RR RRRF RF RF RF(°) (mm) (mm) (°)
=2°
=3°
=1°
=3°
=2°
=4°
=1°
=2°
=0°
=2°
=3°
=1°
=1°
=2°
=0°
=3°
=4°
=2°
=
+1.5mm
= 0mm
=
-1.5mm
=
+0.75mm
= 0mm
=
-0.75mm
➊
NOTE ORIENTATION
NOTE ORIENTATION
17
SHORT REAR SUSPENSION ARMS
#363112-H RIGHT HARD OPTION
#363122-H LEFT HARD OPTION
#363112-G RIGHT GRAPHITE OPTION
#363122-G LEFT GRAPHITE OPTION
LONG REAR SUSPENSION ARMS
#363113-H RIGHT HARD INCLUDED
#363123-H LEFT HARD INCLUDED
#363113-G RIGHT GRAPHITE OPTION
#363123-G LEFT GRAPHITE OPTION
Marked “L”
Marked “R”
2mm
➊
➋
➌
➌
➍
➍
RF
903312
SFH M3x12
From Rear Arm
SHIM 3x6.5x2
Composite eccentric bushings
Composite eccentric bushings
Arm Reamer 3.0mm (HUDY #107643)
If the suspension arm does not move freely
use a HUDY Arm Reamer to size the holes
of the arms.
3.0mm
#363326
ALU LOWER SUSPENSION HOLDER WIDE
FOR HS BULKHEAD - RR
#363317
ALU LOWER SUSPENS. HOLDER WIDE
FOR HS BULKHEAD - RF
Check for free
movement.
0.5°
1°
INITIAL SETTING
CARPET
0.5°
1°
INITIAL SETTING
DIRT
INITIAL SETTING
DIRT
0.5°
1°
0.5°
1°
INITIAL SETTING
CARPET

3. REAR SUSPENSION
ANTI-ROLL BAR
DIRTCARPET
➊
➋
➌
3x4mm
3x8mm
3x3mm
ANTI-ROLL BARS
#362470 1.0mm
OPTION
#362471 1.1mm OPTION
#362472 1.2mm OPTION
#362473 1.3mm INCLUDED
#362474 1.4mm OPTION
#362476 1.6mm OPTION
#362478 1.8mm INCLUDED
#362480 2.0mm OPTION
1.5mm
4mm
DETAIL
18
L=R
2x
Loosen the 3x4 setscrew if
the anti-roll bar does not
turn freely.
Step
➊
901308
SB M3x8
901303
SB M3x3
901304
SB M3x4
902308
SH M3x8
DETAIL
Step check for free movement.
➊
DETAIL
0~1mm
STEP DETAIL
➌
DETAIL
INITIAL SETTING
L=R
In case the anti-roll bar wire is long and will touch the shock absorber then you have to cut
approximately 3mm from each end of the wire.
CUT approx. 3mm
CUT approx. 3mm
SHORT ANTI-ROLL BAR

DIRTCARPET
19
3. FRONT SUSPENSION
303431-K ALU 4.9MM BALL END - BLACK (2)
303454 BALL JOINT 4.9MM - OPEN (4)
361201 COMPOSITE FRONT BUMPER - ONE HOLE
362006 DIFF BULKHEAD - HORIZONTAL SPLIT DESIGN (HS) - FRONT/REAR - SET
362112-H COMPOSITE SUSPENSION ARM FRONT LOWER - HARD
362313 ALU LOWER SUSP. HOLDER FOR HS BULKHEAD - FRONT-FRONT
362315 ECCENTRIC BUSHING SET (2)
362323 ALU LOWER SUSP. HOLDER FOR HS BULKHEAD - FRONT-REAR
362472 ANTI-ROLL BAR 1.2 MM
362478 ANTI-ROLL BAR 1.8 MM
367210 SUSPENSION PIVOT PIN (2)
901303 HEX SCREW SB M3x3 (10)
901304 HEX SCREW SB M3x4 (10)
901308 HEX SCREW SB M3x8 (10)
902308 HEX SCREW SH M3x8 (10)
903312 HEX SCREW SFH M3x12 (10))
303431-K
362323
362315
362313
903312
361201 902308
903312
367210
362112-H
901304
902308
362006
362315
303454
901308
303454
901303
BAG
ANTI-ROLL BARS
#362470 1.0mm
OPTION
#362471 1.1mm OPTION
#362472 1.2mm INCLUDED
#362473 1.3mm OPTION
#362474 1.4mm OPTION
#362476 1.6mm OPTION
#362478 1.8mm INCLUDED
#362480 2.0mm OPTION
362478
362472
SHORT FRONT SUSPENSION ARMS
#362112 MEDIUM OPTION
#362112-H HARD INCLUDED
#362112-G GRAPHITE OPTION
LONG FRONT SUSPENSION ARMS
#362113-H HARD OPTION
#362113-G GRAPHITE OPTION Remove the 3x6.5x2mm shim from each front arm.
362112-H (SHORT)
DIRT
CARPET

3. FRONT SUSPENSION
KICK UP
ROLL CENTER
TRACK-WIDTH
DIRTCARPET
20
The tables describe the amounts of adjustment using the center and outside positions of the eccentric bushings.
The middle position eccentric bushings allow for finer adjustment increments.
The track-width is directly influenced by the size of the
wheels and tires used.
KICK-UP TRACK-WIDTHROLL CENTER
FF FFFF FR FRFR (°) (mm) (mm)
=7°
=6°
=8°
=6°
=5°
=7°
=8°
=7°
=9°
=
+0.75mm
= 0mm
= - 0.75mm
=
+1.5mm
= 0mm
= - 1.5mm
KICK-UP
C-HUB CASTER 6° 7° 8° 9° 10°
6° 12° 13° 14° 15° 16°
9° 15° 16° 17° 18° 19°
Caster is the angle between the steering pivot
axis and the vertical plane. Caster is affected not
only by the C-Hub caster, but also by the front
kick-up angle relative to the flat chassis bottom.
The table indicates how kick up angle effects
total caster.
The XB4’s stock caster blocks are 9°, but 6°
blocks are available as an option.
TOTAL CASTER = C-HUB CASTER+KICK UP
The XRAY alu front lower suspension holders provide great range of adjustment for the front suspension. Using different combinations of eccentric bushings, fine adjustment of front kick-up, roll-center, and front
track-width can be obtained. For more information about the influence of kick-up, front track-width, and roll centers on car handling, please refer to HUDY Set-up Book (#209100).
➊
➊
➋
➌
➌
➍
➍
903312
SFH M3x12
If the suspension arm does not move freely use a
HUDY Arm Reamer to size the holes of the arms .
Arm Reamer 3.0mm (HUDY #107643)
ECCENTRIC BUSHINGS HAVE TWO DIFFERENT OFFSETS FROM THE CENTER.
Middle position = 0.5° or 0.375mm from center. Outer position = 1° or 0.75mm from center.
FRONT ARM
L=R
2mm
2mm
From Front Arm
SHIM 3x6.5x2
Check for free movement.
DETAIL
SHORT FRONT SUSPENSION ARMS
#362112 MEDIUM OPTION
#362112-H HARD INCLUDED
#362112-G GRAPHITE OPTION
LONG FRONT SUSPENSION ARMS
#362113-H HARD OPTION
#362113-G GRAPHITE OPTION
Composite eccentric bushings
DIRT
0.5°
1°
INITIAL SETTING
CARPET
Composite eccentric bushings
0.5°
1°
INITIAL SETTING
CARPET
DIRT