Xray XT4 User manual

INSTRUCTION MANUAL

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.
WARRANTY
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.

4
SYMBOLS USED
EQUIPMENT REQUIRED
Transmitter Steering ServoReceiver
Lexan™ Paint Battery Charger Tires & Inserts
Bearing Oil
(HUDY #106230)
CA glue
Speed Controller LiPo Battery
Pinion Gear with Set-screw
Electric Motor &
Double-sided Tape
(HUDY #107875)
L=R
2x
CA
OIL
Part bags used Assemble left and
right sides the
same way
Assemble in the
specified order
Pay attention
here
Assemble as many
times as specified
(here twice)
Apply CA glue Apply oil
Optional
parts
TL
05
Tighten screw
gently
Completed
assembly
Detail
Apply
threadlock
Apply greaseScale Ensure smooth
non-binding
movement
1:1
DETAIL
Apply cleaner
ITEMS INCLUDED
HUDY Premium Silicone Oils HUDY Premium Silicone Oils HUDY Premium Silicone OilsHUDY Premium Silicone OilsHUDY Premium Silicone Oils Graphite Grease
(HUDY #106210)
Oil 450cSt (#106345) Oil 650cSt (#106365) Oil 100.000cSt (#106610)Oil 30.000cSt (#106530)Oil 10.000cSt (#106510)
Arm Reamer 3.0mm
TOOLS REQUIRED
Side Cutters
(HUDY #189010)
Turnbuckle Wrench
3mm (HUDY #181030)
Reamer (HUDY #107600) or (HUDY #107601)
Tweezer
Combination Pliers
(HUDY #189020)
HUDY TOOLS:
Scissors
(HUDY #188990)
3.0 mm
Special Tool for
turnbuckles & nuts
(HUDY #181090)
Socket 5.5mm
Socket 7.0mm
Allen 2.0mm
Allen 1.5mm
Pocket Hobby Knife
(HUDY #188981)
Professional Multi Tool
(HUDY #183011)

5
XB4 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
(#106051 3.0mm dia x 10mm lenght)
(#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 XT4 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.
NOT INCLUDED
To ensure that you always have access to the most up-to-date version of the HUDY Set-up
Book, you can download it from the HUDY website 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 tables
like these. 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.
Set-up Book
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
361105
364902
364910
SAMPLE OF OPTIONAL PARTS
#32XXXX TYPE OPTION 1
#32XXXX TYPE OPTION 2
#32XXXX TYPE INCLUDED
#32XXXX TYPE OPTION 3
For quick & easy drive pin replacements use
#106000 HUDY Drive Pin Replacement Tool
together with #106036 Ejector Pivot Pin &
Alternating Pivot 2.5mm.

6
BEVEL GEARS
#364935 GRAPHITE OPTION
#364945 ALU OPTION
#364955 STEEL INCLUDED
BEVEL & SATELITTE GEARS + PINS
#304932 + #304980 GRAPHITE INCLUDED
#335030 + #335080 STEEL OPTION
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)
364902 GEAR DIFFERENTIAL FOR 2.5MM PIN - SET
364910 COMPOSITE GEAR DIFFERENTIAL CASE
364955 STEEL DIFFERENTIAL BEVEL GEAR 35T
364961 GEAR DIFF OUTDRIVE ADAPTER FOR 2.5MM PIN - HUDY SPRING STEEL™ (2)
364990 COMPOSITE BEVEL GEAR BUSHING (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)
972050 SILICONE O-RING 5x2 (10)
981210 PIN 2x10 (10)
BAG
364961
364910
964050
964031
972050
364955
903258
364961
304932
941014
981210
972050
964031
964050
304990
364990
981210
941014
304932
304980
972050
O 5x2
972050
O 5x2
964050
S 5x15x0.3
964050
S 5x15x0.3
981210
P 2x10
981210
P 2x10
CUTAWAY VIEW
NOTE ORIENTATION
OIL
OIL
DO NOT USE for optional ALU or GRAPHITE gears
DETAIL
DETAIL
#106210 HUDY GRAPHITE GREASE
#106210 HUDY GRAPHITE GREASE

7
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 9.80g)
➋ Slowly pour oil into the diff and watch the weight.
LOW TRACTION 5 000cSt (HUDY #106450)
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 20 000cSt (HUDY #106520)
MEDIUM-HIGH TRACTION 30 000cSt (HUDY #106530)
SUPER-HIGH TRACTION 40 000cSt (HUDY #106540)
NOTE:
Softer oil increases steering, harder oil increases stability.
TIPS FOR DIFFERENTIALS
REAR DIFERENTIALFRONT DIFERENTIAL
#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
1 140
g
g
1260
1260
11.40g + 1.20g = 12.60gDiff.
Diff. 11.40g + 1.20g = 12.60g
30.000cSt
10.000cSt
Diff.
Diff.
1. FRONT & REAR DIFFERENTIAL
➊
➋
➌
➍
964031
S 3.5x10x0.2
903258
SFH M2.5x8
941014
BB 10x15x4
2x
2x 2x 2x
364990 COMPOSITE BEVEL GEAR BUSHING (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)
972050 SILICONE O-RING 5x2 (10)
981210 PIN 2x10 (10)
Rear diff
Silicone oil 10.000cSt
Fill just above the
cross-pins.
Front diff
Silicone oil 30.000cSt
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

8
BAG
DETAIL
STEP DETAIL
➊
➋
➌
➍
➍
➎
➍➎
OIL
OIL
972050
O 5x2
964050
S 5x15x0.3
981210
P 2x10
CUTAWAY VIEW
STEP DETAIL
Use tweezers to
insert pin
➊
➋
➌
➍
➎
➍
972050
O 5x2
964050
S 5x15x0.3
981210
P 2x10
NOTE ORIENTATION
OIL
OIL
1. GEAR CENTER DIFFERENTIAL
981210
304990
964050
964031
972050
903258
364970
364910 364970
972050
304930
304930
364911
981210
364981
902306
304980
BEVEL & SATELITTE GEARS + PINS
#304930 + #304980 COMPOSITE INCLUDED
#335030 + #335080 STEEL OPTION
#304931 + #304980
GRAPHITE
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)
364901 GEAR CENTER DIFFERENTIAL - SET
364910 COMPOSITE GEAR DIFFERENTIAL CASE
364911 COMPOSITE CENTER GEAR DIFFERENTIAL ADAPTER
364970 CENTER DIFF OUTDRIVE ADAPTER - HUDY SPRING STEEL™ (2)
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)
972050 SILICONE O-RING 5x2 (10)
981210 PIN 2x10 (10)

9
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 9.80g)
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 1.00 g
1250
11.00g + 1.50g = 12.50gDiff.
100.000cSt
1. GEAR CENTER DIFFERENTIAL
902306
SH M3x6
903258
SFH M2.5x8
➊
➋
➌➍
Finish tightening in this order.
Tighten the screws equally but do NOT
tighten them completely.
3x6mm
2.5x8mm
964031
S 3.5x10x0.2
2x Center diff
Silicone oil 100.000cSt
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.

10
2. REAR CENTRAL TRANSMISSION
#106210 HUDY GRAPHITE GREASE
#106213 HUDY JOINT GREASE - OPTION
MARKED “R“
DRIVE SHAFT COVER CAPS
Lubricate the drive shaft connecting joint properly so the drive shaft turns
freely. In the event that not enough grease is used, the connecting pin may lock
and may even, in extreme situations, push through the drive shaft cover cap.
BEVEL DRIVE GEARS
#365114 GRAPHITE OPTION
#365134 STEEL OPTION
CENTRAL SHAFT UNIVERSAL JOINTS
#365440 OPTION
DRIVE SHAFT COLLARS
#365470 COMPOSITE INCLUDED
#365471-K ALU - BLACK OPTION
#365471-O ALU - ORANGE OPTION
DRIVE SHAFT COLLARS
#365470 COMPOSITE INCLUDED
#365471-K ALU - BLACK OPTION
#365471-O ALU - ORANGE OPTION
➊
➋
➌
➍
362003 DIFF BULKHEAD BLOCK SET REAR
363083 XT4 GRAPHITE SHOCK TOWER REAR 3.5MM
365124 STEEL BEVEL DRIVE GEAR 14T
365230 DRIVE SHAFT COUPLING - HUDY SPRING STEEL™
365427 CENTRAL DRIVE SHAFT 105MM - HUDY SPRING STEEL™
365442 CENTRAL SHAFT UNIVERSAL JOINT
365470 COMPOSITE DRIVE SHAFT SAFETY COLLAR - V2 (3)
902306 HEX SCREW SH M3x6 (10)
902310 HEX SCREW SH M3x10 (10)
940510 BALL-BEARING 5x10x4 RUBBER SEALED - OIL (2)
940815 BALL-BEARING 8x14x4 RUBBER SEALED - OIL (2)
980210 PIN 2x10 (10)
981208 PIN 2x8 (10)
364902 GEAR DIFFERENTIAL FOR 2.5MM PIN - SET
364955 STEEL DIFFERENTIAL BEVEL GEAR 35T
BAG
362003
902306
940815
940510
365442
365230
981208
902310
364902+364955
365124
362003
365470
980210
365427
363083
902310
980210
P 2x10
REAR BLOCK
IMPORTANT
CENTRAL DRIVE SHAFT (105mm)
DETAIL
XRAY BALL-BEARINGS
#359050 5x10x4 GREASE OPTION
#940510 5x10x4 OIL INCLUDED
#940814 8x14x4 GREASE OPTION
#940815 8x14x4 OIL INCLUDED
+

11
2. REAR CENTRAL TRANSMISSION
➊
➋
➌
➍
➎
➏
Bearing with BLUE
rubber covers
Follow the TECH TIP on page 5
to prepare graphite parts
940510
BB 5x10x4
902310
SH M3x10
902306
SH M3x6
902310
SH M3x10
THREAD LOCK
8x14x4mm
OIL
GRAPHITE GREASE
(HUDY #106210)
NOTE ORIENTATION
REAR DIFF 10.000cSt
NOTE ORIENTATION
DETAIL
XRAY BALL-BEARINGS
#359050 5x10x4 GREASE OPTION
#940510 5x10x4 OIL INCLUDED
#940814 8x14x4 GREASE OPTION
#940815 8x14x4 OIL INCLUDED
981208
P 2x8
Bearing Oil
(HUDY #106230)
5x10x4mm
OIL
Bearing Oil
(HUDY #106230)
REAR BLOCK
DETAIL
Marked “R”
940815
BB 8x14x4
(INITIAL SETTING)
SHOCKS MOUNTED IN FRONT OF REAR SHOCK TOWER
ALTERNATIVE 1
DO NOT USE FOR BASIC SET-UP
SHOCKS MOUNTED BEHIND REAR SHOCK TOWER
Alternatives shock mounted folow page 39 / step 2 and 3.
NOTE
ALTERNATIVE 2

12
2. FRONT CENTRAL TRANSMISSION
MARKED “F“
DRIVE SHAFT COVER CAPS
Lubricate the drive shaft connecting joint properly so the drive shaft turns
freely. In the event that not enough grease is used, the connecting pin may lock
and may even, in extreme situations, push through the drive shaft cover cap.
#106210 HUDY GRAPHITE GREASE
#106213 HUDY JOINT GREASE - OPTION
DRIVE SHAFT COLLARS
#365470 COMPOSITE INCLUDED
#365471-K ALU - BLACK OPTION
#365471-O ALU - ORANGE OPTION
BEVEL DRIVE GEARS
#365114 GRAPHITE OPTION
#365134 STEEL OPTION
CENTRAL SHAFT UNIVERSAL JOINTS
#365440 OPTION
DRIVE SHAFT COLLARS
#365470 COMPOSITE INCLUDED
#365471-K ALU - BLACK OPTION
#365471-O ALU - ORANGE OPTION
XRAY BALL-BEARINGS
#359050 5x10x4 GREASE OPTION
#940510 5x10x4 OIL INCLUDED
#940814 8x14x4 GREASE OPTION
#940815 8x14x4 OIL INCLUDED
+
➊
➋➌
➍
362002 DIFF BULKHEAD BLOCK SET FRONT
362084 XT4 GRAPHITE SHOCK TOWER FRONT 3.5MM
365124 STEEL BEVEL DRIVE GEAR 14T
365230 DRIVE SHAFT COUPLING - HUDY SPRING STEEL™
365426 CENTRAL DRIVE SHAFT 72MM - HUDY SPRING STEEL™
365442 CENTRAL SHAFT UNIVERSAL JOINT
365470 COMPOSITE DRIVE SHAFT SAFETY COLLAR - V2 (3)
902306 HEX SCREW SH M3x6 (10)
902310 HEX SCREW SH M3x10 (10)
940510 BALL-BEARING 5x10x4 RUBBER SEALED - OIL (2)
940815 BALL-BEARING 8x14x4 RUBBER SEALED - OIL (2)
980210 PIN 2x10 (10)
981208 PIN 2x8 (10)
364902 GEAR DIFFERENTIAL FOR 2.5MM PIN - SET
364955 STEEL DIFFERENTIAL BEVEL GEAR 35T
BAG
365230
365470
981208
362002
940815
902306
362084
902310
902310
365426
980210
365442
940510
365124
FRONT BLOCK
364902+ 364955
362002
IMPORTANT
980210
P 2x10
CENTRAL DRIVE SHAFT (72mm)
DETAIL

13
2. FRONT CENTRAL TRANSMISSION
➊
➋
➌
➍
➎
Bearing with BLUE
rubber covers
Follow the TECH TIP on page 5
to prepare graphite parts
940510
BB 5x10x4
940815
BB 8x14x4
902310
SH M3x10
902310
SH M3x10 NOTE ORIENTATION
THREAD LOCK
NOTE ORIENTATION
NOTE ORIENTATION
DETAIL
FRONT DIFF 30.000cSt
5x10x4mm
OIL
8x14x4mm
OIL
GRAPHITE GREASE
(HUDY #106210)
981208
P 2x8
Bearing Oil
(HUDY #106230)
Bearing Oil
(HUDY #106230)
XRAY BALL-BEARINGS
#359050 5x10x4 GREASE OPTION
#940510 5x10x4 OIL INCLUDED
#940814 8x14x4 GREASE OPTION
#940815 8x14x4 OIL INCLUDED
902306
SH M3x6
DETAIL
Marked “F”

14
ANTI-ROLL BARS
#362470 1.0mm
OPTION
#362471 1.1mm OPTION
#362472 1.2mm OPTION
#362473 1.3mm OPTION
#362474 1.4mm OPTION
#362476 1.6mm OPTION
#362478 1.8mm INCLUDED
#362480 2.0mm OPTION
3. REAR SUSPENSION
323112-M
363321
367210
362315
363311
362315
362478 306219
903312
901304
362003
903312
902308
901303
303431-K
303454
901308
303454
303431-K ALU 4.9MM BALL END - BLACK (2)
303454 BALL JOINT 4.9MM - OPEN (4)
306219 COMPOSITE SET OF SERVO SHIMS (4)
362003 DIFF BULKHEAD BLOCK SET REAR
362315 ECCENTRIC BUSHING SET (2)
362478 ANTI-ROLL BAR 1.8 MM
323112-M XT4 COMPOSITE SUSPENSION ARM REAR LOWER - MEDIUM
363311 ALU REAR LOWER SUSP. HOLDER +2 - FRONT - 7075 T6 (5MM)
363321 ALU REAR LOWER SUSP. HOLDER +2 - REAR - 7075 T6 (5MM)
BAG
#363313
BRASS REAR LOWER SUSPENSION
HOLDER SET +2 - RR+RF
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))
REAR SUSPENSION ARMS
#323112-M MEDIUM INCLUDED
#323112-H HARD OPTION
#323112-G GRAPHITE OPTION

15
TOE-IN
ANTI-SQUAT
ROLL CENTER
TRACK-WIDTH
3. REAR SUSPENSION
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.
Example:
0(RR) - 0 (RF) = 2°
0(RR) - 0.5 (RF) = 2.5°
0(RR) - 1 (RF) = 3°
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°
= 2.5°
= 3°
=3°
=4°
=2°
=2°
=3°
=1°
=4°
=5°
=3°
=
+1.5mm
= 0mm
=
-1.5mm
=
+0.75mm
= 0mm
=
-0.75mm
➊
Check for free movement
Marked “R”
3x6x2mm
Arm Reamer 3.0mm (HUDY #107633)
If the suspension arm does not move freely use a
HUDY Arm Reamer to size the holes of the arms
➊
➋
➌
➌
➍
➍
RR
RF
All possible mounting
alternatives of eccentric bushings
Composite eccentric bushings
INITIAL POSITION
1º 1º0.5º 0.5º0º
Composite eccentric bushings
INITIAL POSITION
1º 1º0.5º 0.5º0º
903312
SFH M3x12
DETAIL DETAIL
REAR SUSPENSION ARMS
#323112-M MEDIUM INCLUDED
#323112-H HARD OPTION
#323112-G GRAPHITE OPTION
306219
SHIM 3x6x2

16
3. REAR SUSPENSION
ANTI-ROLL BAR
➊
➋
➌
3x4mm
3x8mm
3x3mm
1.8mm
L=R
2x
1.5mm
4mm
L=R
0mm
STEP DETAIL
➌
Step check for free movement
➊
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
DETAIL
DETAILDETAIL
ANTI-ROLL BARS
#362470 1.0mm
OPTION
#362471 1.1mm OPTION
#362472 1.2mm OPTION
#362473 1.3mm OPTION
#362474 1.4mm OPTION
#362476 1.6mm OPTION
#362478 1.8mm INCLUDED
#362480 2.0mm OPTION

17
SUSPENSION ARMS
#322112-M MEDIUM INCLUDED
#322112-G GRAPHITE OPTION
3. FRONT SUSPENSION
303121-K ALU SHIM 3x6x0.5MM - BLACK (10)
303431-K ALU 4.9MM BALL END - BLACK (2)
303454 BALL JOINT 4.9MM - OPEN (4)
306219 COMPOSITE SET OF SERVO SHIMS (4)
322112-M XT4 COMPOSITE SUSPENSION ARM FRONT LOWER - MEDIUM
361200 COMPOSITE BUMPER - V2
362002 DIFF BULKHEAD BLOCK SET FRONT - V2
362310 ALU FRONT LOWER SUSP. HOLDER - FRONT - 7075 T6 (5MM)
362315 ECCENTRIC BUSHING SET (2)
362320 ALU FRONT LOWER SUSP. HOLDER - REAR - 7075 T6 (5MM)
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
362320
362315
362310
903312
361200 902308
322112-M
903312
367210
901304
303121-K
306219
902308
362002
306219
306219
362315
303454
901308
303454
901303
BAG
ANTI-ROLL BARS
#362470 1.0mm
OPTION
#362471 1.1mm OPTION
#362472 1.2mm OPTION
#362473 1.3mm OPTION
#362474 1.4mm OPTION
#362476 1.6mm OPTION
#362478 1.8mm INCLUDED
#362480 2.0mm OPTION
362478

18
3. FRONT SUSPENSION
KICK UP
ROLL CENTER
TRACK-WIDTH
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.
Example:
KICK-UP TRACK-WIDTHROLL CENTER
FF FFFF FR FRFR (°) (mm) (mm)
=9°
=8°
=10°
=8°
=7°
=9°
=10°
=9°
=11°
=
+0.75mm
= 0mm
= - 0.75mm
=
+1.5mm
= 0mm
= - 1.5mm
KICK-UP
C-HUB CASTER 7° 8° 9° 10° 11°
6° 13° 14° 15° 16° 17°
9° 16° 17° 18° 19° 20°
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 XT4’s stock caster blocks are 9°, but 6°
blocks are available as an option.
TOTAL CASTER = C-HUB CASTER+KICK UP
0(FF) - 0(FR) = 9°
0.5(FF) - 0(FR) = 9.5°
1(FF) - 0(FR) = 10°
= 9°
= 9.5°
= 10°
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
FR
FF
Composite eccentric bushings
INITIAL POSITION
1º 1º0.5º 0.5º0º
1º
Composite eccentric bushings
INITIAL POSITION
1º 0.5º 0.5º0º
Check for free movement
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 #107633)
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.
3x6x1mm
3x6x0.5mm
3x6x2mm (2x)
DETAIL DETAIL
Marked “F”
306219
SHIM 3x6x2
306219
SHIM 3x6x1
303121-K
SHIM 3x6x0.5
SUSPENSION ARMS
#322112-M MEDIUM INCLUDED
#322112-G GRAPHITE OPTION
NOTE ORIENTATION
NOTE ORIENTATION

19
3. FRONT SUSPENSION
ANTI-ROLL BAR
L=R
2x
1.5mm
4mm
➊
➋
➌
L=R
0mm
STEP DETAIL
➌
Step check for free movement
➊
Loosen the 3x4 setscrew if
the anti-roll bar does not
turn freely
Step
➊
3x4mm
3x3mm
3x8mm
901308
SB M3x8
901303
SB M3x3
901304
SB M3x4
902308
SH M3x8
902308
SH M3x8
DETAIL
DETAIL
DETAIL
DETAIL
ANTI-ROLL BARS
#362470 1.0mm
OPTION
#362471 1.1mm OPTION
#362472 1.2mm OPTION
#362473 1.3mm OPTION
#362474 1.4mm OPTION
#362476 1.6mm OPTION
#362478 1.8mm INCLUDED
#362480 2.0mm OPTION

20
ALU CONICAL SHIMS
#362280 SILVER INCLUDED
#362280-K BLACK OPTION
#362280-O ORANGE OPTION
4. REAR TRANSMISSION
30 2665 COMPOSITE BALL JOINT 4.9MM - CLOSED WITH HOLE (4)
30 6219 CCOMPOSITE SET OF SERVO SHIMS (4)
32 2612 ADJ. TURNBUCKLE 75MM M3 L/R - HUDY SPRING STEEL™ (2)
32 3354-H COMPOSITE UPRIGHT REAR - HARD
32 3382 ALU REAR HUB PLATE FOR MULTI ADJ. UPRIGHT - 1-HOLE
32 5316 XT4 REAR DRIVE SHAFT 92MM WITH 2.5MM PIN - SPRING STEEL™
32 5340 REAR DRIVE AXLE LB - HUDY SPRING STEEL™
32 7321 REAR ARM PIVOT PIN 3x34MM(2)
36 2280 ALU CONICAL SHIM 3x6x2.0MM (10)
36 2316 OPEN ECCENTRIC BUSHING SET (2)
36 2651 BALL END 4.9MM WITH THREAD 8MM (2)
36 3520 REAR WING POST - V2 (2)
36 5230 DRIVE SHAFT COUPLING - HUDY SPRING STEEL™
36 5360 ALU WHEEL HUB 12MM - OFFSET “+4.5MM” (2)
BAG
90 2205 HEX SCREW SH M2x5 (10)
90 2254 HEX SCREW SH M2.5x4 (10)
90 2310 HEX SCREW SH M3x10 (10)
90 2312 HEX SCREW SH M3x12 (10)
94 0513 BALL-BEARING 5x12x4 RUBBER SEALED - GREASE (2)
94 1014 BALL-BEARING 10x15x4 RUBBER SEALED - GREASE (2)
96 0030 NUT M3 (10)
96 1025 WASHER S 2.5 (10)
96 2030 WASHER S 3x6x0.3 (10)
96 2031 WASHER S 3x6x0.1 (10)
98 0210 PIN 2x10 (10)
902310
902254
365230
325316
325340
941014
306219
940513
365360
362280
960030
362651
363520
362651
322612
302665
908210
980210
302665
902205
902312
323354-H
362316
323382
327321
961025
962030
962031
REAR UPRIGHTS
#323354-H COMPOSITE - H INCLUDED
#323354-G COMPOSITE - G OPTION
#323355 ALU OPTION
XRAY BALL-BEARINGS
#940512 5x12x4 OIL OPTION
#941015 10x15x4 OIL OPTION
#940513 5x12x4 GREASE INCLUDED
#941014 10x15x4 GREASE INCLUDED
#323381
ALU REAR HUB PLATE FOR MULTI ADJ.
UPRIGHT - 2-HOLE - SWISS 7075 T6 WHEEL HUBS 12MM
#365360 +4.5mm - 6 slots INCLUDED
#365359 +3.75mm - 5 slots OPTION
#365358 +3.0mm - 4 slots OPTION
#365357 +2.25mm - 3 slots OPTION
#365356 +1.5mm - 2 slots OPTION
#365355 +0.75mm - 1 slot OPTION
#365353 0mm - 0 slots OPTION
#365354 -0.75mm - Lightw. OPTION
WHEEL HUBS 14MM
#365352 +0.75mm OPTION
#365350 0mm OPTION
#365351 -0.75mm OPTION
ALU NUTS M3
#296530-B ALU BLUE OPTION
#296530-K ALU BLACK OPTION
#296530-O ALU ORANGE OPTION
#960030 STEEL SILVER INCLUDED
#960031 ALU SILVER OPTION
#325341
REAR ADJUSTABLE DRIVE AXLE
LB - HUDY SPRING STEEL™ +
325390 ALU SHIM 10x12x2MM (2)