SEALING SYSTEMS

Mechanical Face Seal System

a Commercial Grade
a E ngineered for Propeller Shafts
and Rudder Assemblies
a Face Seal Configuration

Available In 3 Mounting Methods:

B RZ SYSTEM (shown) - Steel Hull
FRP SYSTEM - Fiberglass Hull
WELD-ON SYSTEM - Aluminum Hull

PRODUCT INFORMATION AND SELECTION GUIDE

Duramax Marine® is an ISO 9001:2015 Certified Company

The Next Generation
of Mechanical Face Seals.
Through extensive research, Duramax Marine identified numerous
design inefficiencies in many of today’s mechanical seal designs.
These design problems can result in increased downtime,
lower productivity and even hefty water pollution fines.
Duramax Marine shaft seal experts, based on their research,
designed this revolutionary solution–The Duramax Mechanical
Face Seal System.

2
 Inefficiencies of Other Mechanical Seals
A mechanical face seal is a great choice but many come with hidden design problems.
The face seal is designed with two finely-machined surfaces or faces located perpendicular to the shaft and pressed together to form
a seal. One face surface - the seal ring - is attached to and turns with the propeller shaft. The other face surface -the friction ring -
is part of the seal body. It remains stationary and does not turn with the shaft. The seal ring and the friction ring are arranged so that
they are always in contact with each other. The seal body is normally a compressed rubber bellows or spring-loaded bellows that forces
the stationary friction ring against the rotating seal ring. This creates a very effective and leak-proof seal.
Since face seals do not use the propeller shaft as a sealing surface, you do not have shaft wear caused by the packing in stuffing boxes
or the rubber lips found in lip seals. Also, the shaft is allowed to rotate with less resistance, which increases fuel economy and helps
provide better propulsion system performance.
 friction ring and the seal body have an inside diameter larger than the propeller shaft diameter. This prevents the propeller
The
shaft from hitting the seal body and causing leakage through the seal faces. This also allows for shaft misalignment, excessive
dimensional runout and vibration in the propulsion system.
Today there are many face seal designs to choose from. The difference among them are the method of installation and
removal, type of materials used and design features.

CARBON FACE SEALS

Seal ring setscrews can damage the propeller shaft.
Design Flaws Lead to Shaft Damage, The seal ring is secured to the propeller shaft with setscrews which
Leakage and Seal Failure. are tightened into and can damage the surface of the propeller shaft.
The setscrews also electrically connect the seal ring to the propeller
shaft and can lead to galling and/or electrolysis. If the seal ring galls
CARBON/GRAPHITE FRICTION RING
to the shaft, it must be cut into pieces to remove it.
Cloth Covered
Rubber Bellows
CONICAL FACE SEALS
Any Shaft Vibration or Misalignment
Will Cause Leaks.
Stainless Steel
Seal Ring
CONICAL MARINE FACE SEAL
Set Srews
Conical Shaped
Face Seal
 arbon graphite is very brittle and causes corrosion
C
of stainless steel.
The seal face consists of carbon graphite, which is brittle and subject Neoprene
to chipping, scratching or pitting. This can result in leakage and seal Bellows
failure. Also, carbon graphite used in salt water can create galvanic
corrosion of the stainless steel shafting materials. Stainless steel
shafting manufacturers advise against the use of carbon graphite Friction Ring
with stainless steel shafting.
Conical marine face seals have a seal ring with a beveled face
Seal ring design makes it very difficult to install or remove. and a mating friction ring with a counter bevel. Any vibration
Embedded in the inside diameter of the seal ring are two O-rings or misalignment will cause the conical face to wear into an oval
that keep water from leaking past the seal ring into the vessel. or elliptical shape. This prevents the seal from seating correctly,
The seal ring inside diameter is only slightly larger than the diameter causing it to leak.
of the propeller shaft. This close tolerance between the shaft
and seal ring requires careful installation or you could damage Only good in low RPM operations.
these O-rings by cutting them on the key-way slots. If you damage These seals work in low RPM applications, but for most marine
the O-rings, there will be leakage through the inside diameter applications, the propeller shaft RPM is too high and there is
of the seal ring. Also, if there is galling or marking on the shaft, too much propulsion system movement for this type of face
the seal ring cannot be installed without first polishing the shaft. seal to operate properly.
3
BELLOWS TYPE FACE SEALS LIP SEALS
Bellows-type seals offer minimum protection Tight fit of lip to propeller shaft creates seal,
if breakdown occurs. as well as leaks.
SPRING LOADED Safety Shield Bearing Water
RUBBER LIP SEAL Grooves
RUBBER/SILICON BELLOWS

Stainless Steel
Retaining Rings

Shaft Clamp
Seal Ring
Friction Ring Another common type of mechanical seal used on rotating propeller
shafting is the lip seal. Lip seals are similar to stuffing boxes in that
they utilize the propeller shaft as a sealing surface. A rubber ring with
Any bellows-type seal uses the bellows as the only barrier a lip on the inside diameter fits over the propeller shaft.
between you and the sea. If the bellows should fail The tight interference fit between the rubber lip and the propeller
or be damaged, a serious leakage situation will occur. shaft ensures continuous contact and creates a seal.

A rubber bellows is adversely affected by temperature, Shaft imperfections will damage lip seal, result in leakage.
environment and age. In order for the lip seal to operate properly, the propeller shaft must be
Both the Carbon Face Seal (fig. 1) and the Conical Face Seal very smooth. If the shaft is pitted or marred, it will damage the lip seal
use a convoluted rubber bellows as the seal body and to mainta or will not allow a proper fit of the lip seal to the shaft. This will result
in the required pressure on the seal faces. When a rubber bellows in leakage through the lip seal.
is used as a spring, the seal depends on the compressibility
and durometer (hardness) of the rubber to maintain pressure
Frictional heat causes lip seal and propeller shaft wear.
at the faces to create the seal.
The rubber lip seal is not a very effective solution for sealing marine
propeller shafts. As the propeller shaft turns, frictional heat is created
The main problem with this type of seal is that the physical which causes the rubber lip seal and propeller shaft to wear - leading
properties of rubber, regardless of type, are affected by to eventual leakage through the lip seal.
temperature, environment and age. As the aging rubber loses
its physical properties, the amount of pressure on the seal face
Lip seal causes severe wear on stainless steel.
decreases. This can result in seal leakage and requires you
to adjust the face pressure by adding additional compression Shaft wear can be severe when using a lip seal with stainless steel
to the rubber bellows or eventually replacing the rubber bellows. shafting material. Stainless steel has great tensile strength but due
to its high nickel content, it has low resistance to abrasion. Another prob-
lem when using a rubber lip seal with stainless steel shafting
Rubber eventually deteriorates, cracks and leaks.
is crevice corrosion. The tight interference fit of the rubber lip to the
As rubber ages, it becomes less compliant and brittle to the stainless steel shaft results in oxygen deprivation of the stainless steel
point where it will deteriorate, crack and leak. Several face seal and the shaft cannot oxidize to protect itself. This results in
manufacturers have recognized this problem and have incorporated a groove being etched into the shaft - causing the lip seal to leak.
fabric reinforcement in an attempt to assist with structural strength.
Also, several manufacturers have molded a spring into their rubber
Shaft misalignment, vibration will cause seal leakage.
bellows. This is an improvement over the convoluted rubber bellows
because the spring maintains a constant pressure on the seal faces Propeller shaft misalignment and shaft line vibration will cause lip seals
for the life of the seal. However, it does not eliminate the aging pro- to leak. One lip seal manufacturer has tried to solve this problem by
cess of the rubber itself. incorporating into his design a propeller shaft bearing to assist with
reducing the shaft line vibration that causes seal leakage.
Bellows can be accidentally jarred out of position.
Problems occur with both single- and double-lip seal systems.
Another problem with bellows-type face seals is that the flexibility
of the bellows can allow the seal faces to be accidentally knocked Several types of lip seals are available for sealing marine propeller
off their seat or sealing surfaces which will allow a major leakage shafts. They vary in the number of rubber lips used per seal assembly
of water into the vessel. and the type of lubricant used. One type uses a single lip with water
lubrication. Another type uses a double lip seal lubricated with
transmission fluid. This seal has a reservoir of more than 16 ounces of
transmission fluid. As the seal wears, transmission fluid can leak out
4 into the seawater which could result in federal water pollution fines.
The Revolutionary
Mechanical Face Seal Solution.
Simply put, the superior design of the Duramax Shaft
Seal System makes it the best choice for your shaft
seal requirements.
It eliminates the inefficiencies of all other designs.
The Duramax system is easy to install and remove
and increases performance.
This “maintenance-free" mechanical face seal
has run in some applications for over 20,000 running
hours without requiring replacement parts*.
And, maintenance-free means there are no lip seals
or packing to change - and no need for constant
adjustment once properly installed.
*This service life is not guaranteed, it may vary depending upon conditions of use.

Versatile Adapter Ring-

with matching adapters, that adapt the
Duramax Shaft Seal System to your boat.
Covered Spring Chamber-
provides a secondary water seal
for extra backup protection.

Stationary Friction Ring-

oil-impregnated nylon seal ring
with hose barb connection for
air venting or water injection

Rotating Seal Ring-

made of precision marine-grade,
Self-Centering Shaft Clamp- non-corrosive stainless steel, electrically
isolated from the shaft by an O-ring.
split C clamp design for non-marring,
perfectly-aligned grip of propeller shaft.

5
 THE DURAMAX SHAFT SEAL SYSTEM DESIGN FEATURES

NYLON FRICTION RING UNIQUE TWO-PIECE SEAL RING/ ASSEMBLY ELECTRICALLY

eliminates the problems SHAFT CLAMP ASSEMBLY ISOLATES the seal ring from
associated with carbon graphite. Allows for easy installation and the propeller shaft.
removal.
The Duramax Friction Ring is the The Duramax Shaft Clamp/Seal Ring
stationary part of the seal face. The Duramax Seal Ring/Shaft Clamp design electrically isolates the stainless
It is made of impact-resistant, high Assembly has a unique two-piece design. steel seal ring from the propeller shaft
temperature, oil-impregnated nylon A non-conductive Delrin** shaft clamp and eliminates the galling of the seal
that is impervious to shock or blows. is utilized to attach the assembly to the ring to the propeller shaft. Also
It can withstand high temperatures up propeller shaft. It is a true split clamp completely eliminated is damage
to 350° Fahrenheit. This material also design that does not gall or mark the caused by attaching the seal ring to
eliminates the galvanic corrosion shaft when it is clamped in place. the propeller shaft with setscrews.
and brittleness problems associated
with carbon graphite materials. Plus, it opens large enough to slide over **Delrin is a registered trademark
the propeller shaft even if it is galled of E.I. DuPont De Nemours & Co. (Inc),
SEAL RING/SHAFT O-Ring
CLAMP ASSEMBLY or pitted! The 316 stainless steel seal Wilmington, Delaware
Clamp
Screw ring is designed with the inside diameter
machined 0.015 inches (0.38mm) larger
Compression than the propeller shaft. It has a 45-degree
Screw bevel machined in the inside diameter
which allows an O-ring to be compressed
Seal Ring into the slope when the seal ring is
attached to the shaft clamp.
Shaft Clamp

Air Vent/Water Injection Fitting Spring Cover

Sea Gasket
Stainless Steel
Seal Ring Coil Spring

Prop Shaft

Shaft Clamp
ENGINE
PROPELLER
Friction Ring Adapter Ring
Slide Ring
6
 COMPOSITE, NON-RUBBER STAINLESS STEEL TENSION AIR VENT/WATER INJECTION
MAIN SEAL BODY SPRING ensures a reliable seal. FITTING ensures adequate water
eliminates the weakest point lubrication.
In order for a mechanical face seal
of standard seals.
to work properly, face tension or pressure In order for a mechanical face seal
Most mechanical seals use a rubber must be placed on the rotating seal ring and to work correctly, a thin film of water
bellows or spring-loaded rubber/silicone the stationary friction ring. This tension is required between the two seal faces.
hose to connect the seal to your boat. This water film acts as a lubricant,
creates the seal between the two faces. carries away frictional heat and maintains
This type of connection works - however,
it is the weakest point of the seal assembly. Mechanical face seal manufacturers the proper seal face temperature.
If the bellows or hose is punctured or if who utilize a rubber bellows rely on the Every Duramax Shaft Seal System has
the material weakens or fails, large compressibility and durometer of the rubber an air vent/water injection fitting that
amounts of water will enter the vessel. to maintain the face tension. As the rubber provides adequate water lubrication at the
Also, severe leakage will occur if someone ages and loses its physical properties, seal face. For a displacement hull (sailboat,
steps on the seal body or accidentally the amount of face pressure decreases, trawler, etc.) - the fitting is used to vent
displaces the seal off center. which affects the reliability of the seal. or bleed off any air trapped at the seal face,
The Duramax Shaft Seal System which could prevent water from reaching
The Duramax Main Seal Body has been eliminates the problems associated the seal faces.
designed to eliminate the use of a rubber with rubber bellows by utilizing an
bellows or spring-loaded hose. It employs engineered 316 stainless steel coil spring. For high-speed hulls (approximately above
a rigid, spring-loaded, composite body The spring diameter and number of coils 12 knots) - as the vessel reaches higher
that cannot be knocked off the seal face. have been designed and tested to provide speeds, a vacuum can occur on the stern
The main seal body is attached to an adapt- the proper face pressure that creates a tube which draws the lubricating seawater
er ring by a neoprene sea gasket. reliable seal and ensures a long wear life outboard and starves the seal faces.
If this sea gasket were to fail, the seawater of the seal faces. In these types of installations, the fitting
would enter the sealed spring chamber. is used to inject water to the seal faces.
This special design feature provides Adapter Ring
a secondary seal to the main body seal
and would prevent the entry of seawater
into the vessel.
Sea Gasket
Adjusting Screws

O-Ring
Flat Washer

Spring Cover O-Rings

Hose Barb Tie Lok Rie

Self Tap Screws

Slide Ring
Safety Shield
Tie Lok Rie

O-Ring
Clamp Screw Tension Spring

Compression Screw
Friction Ring

Seal Ring

Shaft Clamp
7
 Choosing the Right Duramax® Shaft Seal
System for Your Vessel is Easy.
The Duramax Shaft Seal System, manufactured
in the U.S.A., is available for shafts from 3/4
to 6-3/4 inches diameter. They are easy to install
for the O.E.M. or retrofit installations.
To find the right one, go to the “DXU Shaft Seal
Assembly" data sheet and look in the left-hand
column for your shaft diameter. Right next to the
shaft diameter listing is the part number for the
Duramax Shaft Seal Assembly.

We offer three different

shaft seal system designs
to meet your specific need.
Our sales engineers are ready
to answer your questions and provide
assistance with selecting the Duramax
Shaft Seal System. Please call us
at 440-834-5400 or FAX us
at 440-834-4950, or visit our website,
www.DuramaxMarine.com.

THE DURAMAX BRZ SHAFT SEAL SYSTEM

Integral Mounting Flange
Maintenance-Free Seal
Back-Up Air Seal

Seal Ring Assembly Bronze Housing

The Economical Choice for Pleasure or Commercial Vessels.

Whether your vessel is a mega yacht or a passenger ferry, this system is ideal. It incorporates the Duramax Shaft Seal System
with either an aluminum or bronze adapter ring housing with an integral mounting flange and back-up air seal feature. Now,
you can inflate the back-up air seal while the shaft is stationary - allowing you to make minor adjustments to the seal and stop
water flow in the case of catastrophic failure of the seal. And, the integral mounting flange is undrilled to make attachment sim-
ple - you can use your own bolt pattern. For shaft diameters 2-1/2 - 6-3/4 inches.

8
 THE DURAMAX FRP SHAFT SEAL SYSTEM
Maintenance-Free Seal

Seal Ring Assembly

Factory Tested Bond

Designed with the Fiberglass Builder in Mind.

Perfect for new fiberglass vessel construction, this system incorporates the “maintenance-free" Shaft
Seal System with an integrated FRP stern tube and a Johnson Cutless‚ Bearing. The factory-tested bond
between shaft seal and FRP tube verifies seal attachment to stern tube. And, the FRP stern tube saves
production time by allowing you to fiberglass the engineered system directly into your boat.

THE DURAMAX WELD-ON SHAFT SEAL SYSTEM

Maintenance-Free Seal Recess for
Stern Tube

Seal Ring Assembly Aluminum Adapter Ring

Designed with the Aluminum Builder in Mind.

When constructing an aluminum vessel, this is ideal for you. It incorporates the “maintenance-free"
Duramax Shaft Seal System with an aluminum adapter ring. This ring saves production time by allowing
the installer to weld the seal assembly directly to the aluminum stem tube - thus eliminating the need
for a seal adapter, hose and hose clamps. And, the compression clips pre-compress the tension spring
for easier installation.
For production boat builders, Duramax has additional design options not shown in this booklet.
Contact us for more information on these options.

WE ADAPT OUR SYSTEM TO YOUR VESSEL - RATHER THAN YOU ADAPTING

YOUR VESSEL TO OUR SEAL.
In order to reduce installation time and save you money, Duramax has designed and developed a series
of mounting adapters for flanged, hose connection, stern tube and through-hull installations.
These adapters allow us to adapt the Duramax Shaft Seal System to your vessel.
To select the proper adapter for your stern tube or deadwood attachment, go to the adapter data sheets
on the following pages. You will need to know the outside diameter size of your stern tube and the space
available from the aft end of your shaft coupling to the forward end of the stern tube.

9
DXU Shaft Seal Assembly

The shaft seal assembly is the main body of the Duramax Shaft
Seal System. To determine which assembly to order, measure
the propeller shaft diameter and match the shaft size on the
adjacent chart. A Compressed

0B
Engine

Shaft Size A B Shaft Diameter Adapter Part Number

3/4 7-1/2 3-1/2 3/4" DXU-0750
7/8 7-1/2 3-1/2 7/8" DXU-0875
1 7-5/8 4-1/2 1" DXU-1000
1-1/8 7-5/8 4-1/2 1-1/8" DXU-1125
1-1/4 7-5/8 4-1/2 1-1/4" DXU-1250
1-3/8 7-5/8 4-1/2 1-3/8" DXU-1375
1-1/2 7-5/8 4-1/2 1-1/2" DXU-1500
1-3/4 7-13/16 4-1/2 1-3/4" DXU-1750
2 7-7/8 5-1/2 2" DXU-2000
2-1/4 7-7/8 5-1/2 2-1/4" DXU-2250
2-1/2 8-3/8 5-1/2 2-1/2" DXU-2500
2-3/4 8-3/8 5-1/2 2-3/4" DXU-2750
3 9-1/4 7 3" DXU-3000A
3-1/4 9-1/8 7 3-1/4" DXU-3250
3-1/2 9-1/8 7 3-1/2" DXU-3500
3-3/4 9-1/8 7 3-3/4" DXU-3750
4 9-1/2 8 4" DXU-4000A
4-1/4 9-1/2 8 4-1/4" DXU-4250A
4-1/2 9-1/2 8 4-1/2" DXU-4500A
4-3/4 10-1/4 8 4-3/4" DXU-4750A
5 10-15/16 10 5" DXU-5000
5-1/4 10-15/16 10 5-1/4" DXU-5250
5-1/2 10-15/16 10 5-1/2" DXU-5500
5-3/4 10-15/16 10 5-3/4" DXU-5750
6 10-15/16 11 6" DXU-6000
6-1/4 10-15/16 10
6-1/2 10-15/16 11
6-3/4 10-15/16 11 If your size is not listed, please call Duramax Marine at 440-834-5400

10
IXU Deluxe Installation Kit
The deluxe installation kit includes water connection fittings
with hose and clear vinyl safety shield. If your shaft size is not
listed, please call Duramax Marine.
If your shaft size is not listed,
please call Duramax Marine at 440-834-5400

Shaft Diameter Water Hose I.D. Kit Part No. Shaft Size A B C Notes
DXU 0750 thru 0875 8-1/2 3-1/2 2 1-7/8
3/4" thru 7/8" 1/4"  IXU-0750
DXU 1000 thru 1750 8-15/16 4-1/2 2 2-3/8
1" thru 1-3/4" 1/4"  IXU-1000 DXU 2000 thru 2750 9-15/16 5-1/2 3-1/4MAX* 2-7/8
2" thru 2-3/4" 1/4"  IXU-2000 DXU 3000 thru 3750 11-13/16 7 3-1/4MAX* 3-5/8
DXU 4000 thru 4750 12 8 3-1/4 4-1/8
3" 1/4"  IXU-3000
DXU 5000 thru 5750 12-5/16 10 3-1/4 5-1/8
3" thru 3-3/4" 3/8"  IXU-3000A/IXU-3250 DXU 6000 thru 6750 12-5/16 11 3-1/4 5-5/8
4" thru 4-3/4" 3/8"  IXU-4000
5" thru 5-3/4" 3/8"  IXU-5000
6" thru 6-3/4" 3/8"  IXU-6000

11
SXU Stern Tube Clamp Adapters
To determine which stern tube clamp adapter to order, measure the propeller shaft and stern
tube diameters. Match the diameters on the adjacent chart to determine the part number.
If your size is not listed, please call Duramax Marine at 440-834-5400

MEASURE AT DISTANCE "C"

FROM END OF STERN TUBE

CL
FORWARD END
E OF STERN TUBE
DISTANCE STERN TUBE GOES
INTO STERN TUBE CLAMP ADAPTER D
INSIDE OF HULL AFT END OF
TRANSMISSION FLANGE
SECTION A-A AFT END OF STERN TUBE CLAMP A
C
SHAFT SEAL O.D.

A
B

CL E
INSIDE OF HULL
MINIMUM CLEARANCE NEEDED
FROM CENTER OF STERN TUBE TO
A
INSIDE OF HULL

Shaft Diameter Stern Tube Adapter Part Number

Diameter
3/4" thru 7/8" 1-1/2" SXU-0750-1500
3/4" thru 7/8" 1-5/8" SXU-0750-1625
3/4" thru 7/8" 1-3/4" SXU-0750-1750
1" 1-1/2" SXU-1000-1500
1" thru 1-1/4" 1-3/4" SXU-1000-1750
1" thru 1-1/4" 2" SXU-1000-2000
1" thru 1-1/4" 2-1/4" SXU-1000-2250
1" thru 1-3/8" 2" SXU-1000-2000A
1" thru 1-3/4" 2-3/8" SXU-1000-2375
1" thru 1-3/4" 2-1/2" SXU-1000-2500
1" thru 1-3/4" 2-5/8" SXU-1000-2625
1" thru 1-3/4" 2-3/4" SXU-1000-2750
1" thru 1-3/4" 2-7/8" SXU-1000-2875
1" thru 1-3/4" 2-15/16" SXU-1000-2938
1" thru 1-3/4" 3" SXU-1000-3000
2" 2-3/4" SXU-2000-2750
2" thru 2-1/4" 2-7/8" SXU-2000-2875
2" thru 2-1/4" 3" SXU-2000-3000
2" thru 2-1/2" 3-3/8" SXU-2000-3375 Shaft Size A B C Notes
2" thru 2-3/4" 3-1/2" SXU-2000-3500 DXU 0750 thru 0875 8-1/2 3-1/2 2 1-7/8
2" thru 2-3/4" 3-5/8" SXU-2000-3625 DXU 1000 thru 1750 8-15/16 4-1/2 2 2-3/8
2" thru 2-3/4" 3-3/4" SXU-2000-3750 DXU 2000 thru 2750 9-15/16 5-1/2 3-1/4MAX* 2-7/8
2" thru 2-3/4" 3-7/8" SXU-2000-3875 DXU 3000 thru 3750 11-13/16 7 3-1/4MAX* 3-5/8
2" thru 2-3/4" 4" SXU-2000-4000 DXU 4000 thru 4750 12 8 3-1/4 4-1/8
2" thru 2-3/4" 4-1/2" SXU-2000-4500 DXU 5000 thru 5750 12-5/16 10 3-1/4 5-1/8
2" thru 2-3/4" 5" SXU-2000-5000 DXU 6000 thru 6750 12-5/16 11 3-1/4 5-5/8
3" thru 3-1/4" 4" SXU-3000-4000
3" thru 3-3/4" 4-1/2" SXU-3000-4500
3" thru 3-3/4" 5" SXU-3000-5000
3" thru 3-3/4" 5-9/16" SXU-3000-5563
3-1/2" 6" SXU-3500-6000
4" thru 4-3/4" 6" SXU-4000-6000
5" 6" SXU-5000-6000

12
HXU Hose Adapters
To determine which hose adapter to order, measure the propeller shaft Shaft Diameter Stern Tube Adapter Part Number
and stern tube diameters. Match the diameters on the adjacent chart Diameter
to determine the part number. 3/4" thru 7/8" 1-1/2" HXU-0750-1500
3/4" thru 7/8" 1-3/4" HXU-0750-1750
If your size is not listed, please call Duramax Marine at 440-834-5400 1" thru 1-1/8" 1-3/4" HXU-1000-1750
1" thru 1-1/4" 2" HXU-1000-2000
1" thru 1-1/2" 2-1/4" HXU-1000-2250
1" thru 1-3/4" 2-3/8" HXU-1000-2375
1" thru 1-3/4" 2-1/2" HXU-1000-2500
1" thru 1-3/4" 2-5/8" HXU-1000-2625
1" thru 1-3/4" 3" HXU-1000-3000
1" thru 1-3/4" 3-1/2" HXU-1000-3500
2" 2-3/4" HXU-2000-2750
2" thru 2-1/4" 2-7/8" HXU-2000-2875
2" thru 2-1/4" 3" HXU-2000-3000
2" thru 2-3/4" 3-1/2" HXU-2000-3500
2" thru 2-3/4" 4" HXU-2000-4000
2" thru 2-3/4" 4-1/4" HXU-2000-4250
2" thru 2-3/4" 4-1/2" HXU-2000-4500
2" thru 2-3/4" 5" HXU-2000-5000
3" thru 3-1/4" 4" HXU-3000-4000
3" thru 3-3/4" 4-1/2" HXU-3000-4500
3" thru 3-3/4" 5" HXU-3000-5000
4" 5" HXU-4000-5000
4" thru 4-3/4" 5-1/2" HXU-4000-5500
4" thru 4-3/4" 6" HXU-4000-6000
4" thru 2-3/4" 7" HXU-4000-7000
5" 6" HXU-5000-6000
5" thru 5-1/2" 6-1/2" HXU-5000-6500
5" thru 5-3/4" 7" HXU-5000-7000
6" 7" HXU-6000-7000
6" thru 6-1/2" 7-1/2" HXU-6000-7500
6" thru 6-3/4" 8" HXU-6000-8000

A AFT END OF
FORWARD END TRANSMISSION FLANGE
OF STERN TUBE
C
SHAFT SEAL O.D.
EXHAUST HOSE

CL
INSIDE OF HULL
HOSE ADAPTER

Shaft Size A B C Notes

DXU 0750 thru 0875 10-3/4 3-1/2 2
DXU 1000 thru 1750 11-3/16 4-1/2 2
DXU 2000 thru 2750 11-15/16 5-1/2 2
DXU 3000 thru 3750 13-15/16 7 2
DXU 4000 thru 4750 15-1/8 8 3
DXU 5000 thru 5750 16-1/16 10 3
DXU 6000 thru 6750 16-1/16 11 3

13
FXU Flange Adapters
The flange adapter is used for new construction and for major Shaft Diameter Flange Adapter Part Number
overhauls or retrofit. Diameter
If your size is not listed, please call Duramax Marine at 440-834-5400 3/4" thru 7/8" 5" FXU-0750-THR
1" thru 1-3/4" 6" FXU-1000-THR
2" thru 2-3/4" 8" FXU-2000-THR

Shaft Diameter Flange Adapter Part Number

Diameter

3" thru 3-3/4" 9" FXU-3000-BOLT

4" thru 4-3/4" 10" FXU-4000-BOLT
5" thru 5-3/4" 12-1/2" FXU-5000-BOLT
6" thru 6-3/4" 13-1/2" FXU-6000-BOLT

D
AFT END OF
FORWARD END OF DEADWOOD, TRANSMISSION FLANGE
BULKHEAD, OR MATCHING FLANGE A

FLANGE ADAPTER O.D.

CL

SEAL O.D.

INSIDE OF HULL

Shaft Size A B C Notes

DXU 0750 thru 0875 8-3/4 3-1/2 5
DXU 1000 thru 1750 9-3/16 4-1/2 6
DXU 2000 thru 2750 9-15/16 5-1/2 8
DXU 3000 thru 3750 11-15/16 7 9
DXU 4000 thru 4750 12-1/8 8 10
DXU 5000 thru 5750 13-1/16 10 12-1/2
DXU 6000 thru 6750 13-1/16 11 13-1/2

14
TXU Thru-hull Adapters
The thru-hull adapter is used for new construction
and for major overhauls or retrofit. Shaft Diameter Adapter Part Number
Diameter
If your size is not listed, please call Duramax Marine at 440-834-5400
3/4" thru 7/8" TXU-0750
1" thru 1-3/4" TXU-1000
2" thru 2-3/4" TXU-2000
3" thru 3-3/4" TXU-3000
4" thru 4-3/4" TXU-4000
5" thru 5-3/4" TXU-5000
6" thru 6-3/4" TXU-6000

D
AFT END OF
FORWARD EDGE OF TRANSMISSION FLANGE
KNEE OR BULKHEAD A

SHAFT SEAL O.D.

CL
INSIDE OF HULL

Shaft Size A B Notes

DXU 0750 thru 0875 8-1/4 3-1/2
DXU 1000 thru 1750 8-11/16 4-1/2
DXU 2000 thru 2750 9-7/16 5-1/2
DXU 3000 thru 3750 11-7/16 7
DXU 4000 thru 4750 11-5/8 8
DXU 5000 thru 5750 12-5/16 10
DXU 6000 thru 6750 12-5/16 11

15
INNOVATION. Duramax Marine® is committed to providing excellence in every product
we manufacture. Our Johnson Cutless® marine and industrial bearings,
EXPERIENCE. heat exchangers, impact protection systems and sealing systems are known
worldwide for their engineered quality and dependable performance. Please contact
RESULTS. the factory for information on any of the following Duramax Marine® products:

JOHNSON CUTLESS® WATER-LUBRICATED BEARING SYSTEMS

Johnson Cutless® Sleeve and Flanged Bearings

DURAMAX® ADVANCED WATER-LUBRICATED BEARING SYSTEMS

Johnson® Demountable Stave Bearings
ROMOR®I Stave Bearings and Segmental Housings
ROMOR® C- Partial Arc Bearings
DMX® Polymer Alloy Bearings
DuraBlue® Bearings, Rudder & Pintle Bushings, Thrust Washers, and Wear Pads
Industrial Pump Bearing Systems

DURAMAX® HEAT EXCHANGE SYSTEMS

DuraCooler® Keel Coolers
Duramax® Demountable Keel Coolers
Duramax® BoxCoolers

DURAMAX® IMPACT PROTECTION SYSTEMS

Johnson® Commercial Dock Bumpers, Fenders & Tow Knees
LINERITE® Composite Batterboard Systems

DURAMAX® SHAFT SEALING SYSTEMS

DryMax® Shaft Seal & Rudder Seal
Duramax® Mechanical Shaft Seal
Johnson® Heavy-Duty Air Seal Stuffing Boxes
Duramax® Ultra-X® High Performance Compression Packing

©2023 Duramax Marine®

17990 Great Lakes Parkway
Hiram, Ohio 44234 U.S.A.
PHONE 440.834.5400
FAX 440.834.4950
info@DuramaxMarine.com
www.DuramaxMarine.com
Duramax Marine® is an ISO 9001:2015 Certified Company

DM-1020.113 MECHSS 05-05-23