Overview
The Dometic SeaStar HC53453 is a front-mount pivoting hydraulic steering cylinder for supported outboard engines. It is the standard cylinder specified for many SeaStar outboard systems in normal-use applications. The -3 cylinder has positionable stainless steel ORB hose fittings, an 8-inch stroke, and an 8.34-cubic-inch fluid volume. Confirm the engine model, year, steering configuration, and available space before selecting a cylinder.
Check before ordering: Engine fitment depends on the exact outboard and whether the boat has one or multiple engines. Some engines require a different cylinder, spacer kit, tiller bolt, or tie bar. A -3 ORB cylinder must not be fitted with older NPT elbows such as HF6145.
What the HC5345-3 does
The cylinder turns the outboard in response to hydraulic pressure from a compatible SeaStar helm and hose system. Dometic describes its improved sealing system and positionable fittings as service and hose-routing features. The number of wheel turns varies with the helm; Dometic gives approximately 4.9 turns lock-to-lock with a typical 1.7-cubic-inch helm in the 2027 guide.
This listing is for the cylinder. For a complete steering system, SeaTech offers HK6400-4 standard helm, HK6400TC-4 Classic Tilt and HK6400TS-4 Sport Tilt kit listings that specify this cylinder. The base Dometic HK6400-4 package contains the HH5271-4 helm and two bottles of fluid but no hoses; check the selected hose option on the SeaTech kit listing.
Replacing an older HC5345
Dometic lists the earlier HC5345 as replaced by HC5345-3. Check the existing hose elbows when updating an older system: the -3 cylinder uses ORB fittings and the old NPT fittings cannot be threaded into its ports. The engine application and mounting clearance still need to be checked against the current guide.
Repair and steering-kit shortcuts
For leaking end glands, the HS5157 seal kit with pin wrench is the manual-listed repair kit. For brackets, fittings, tiller bushings, and straps, use the Parts & Kits tab. The 2027 Guide tab gives the cylinder-specific engine rows and twin tie bars.
Compatibility
System limits for normal use
The 2027 Dometic guide gives these system-configuration limits for SeaStar front-mount HC53XX-3 cylinders. They do not establish engine-specific fitment on their own. The engine application chart, tie bar selection, vessel rating, and operating conditions must also agree.
| Configuration | Guide limit | Additional selection |
|---|---|---|
| Single outboard, one cylinder | Up to 350 HP and 75 mph in normal use | Confirm the exact engine in the single-engine application guide. Engines over 300 HP require the specified high-strength tiller bolt. |
| Twin non-counter-rotating outboards, one cylinder | Up to 450 HP total and 55 mph in normal use | Confirm the twin-engine chart and select the listed tie bar for the engines and center distance. |
| Twin counter-rotating outboards, one cylinder | Up to 600 HP total and 55 mph in normal use | Confirm the twin-engine chart and tie bar. Some engines instead require HC5358-3 or Tournament hardware. |
Boats driven aggressively, with surface-piercing propellers or highly elevated engines, or above the guide's speed limit require a different steering-system review. Triple-engine arrangements are treated separately in the guide; do not assume that one HC5345-3 is the correct setup.
Selected engine examples from the 2027 guide
These are examples, not the complete application chart. Model-year ranges and notes are part of the fitment decision. The 2027 Guide tab reproduces all HC5345-3 rows from the normal-use single- and twin-engine charts, with their applicable notes and tie bars.
| Engine | Guide's HC5345-3 listing | Check before ordering |
|---|---|---|
| Honda 115 HP four-stroke | 2011 onward, single-engine chart; also listed for twin engines | Identify the full model and select the applicable twin tie bar if needed. |
| Mercury 175–225 HP 3.4L V6 four-stroke | 2017 onward | The twin-engine chart specifies HO6001EM for one cylinder or HO6002 for two cylinders; verify the engine and installation notes. |
| Suzuki 150–200 HP four-cylinder | 2013 onward | Do not generalize to Suzuki 115–140 HP models, for which the guide specifies other cylinders. |
| Yamaha 75–115 HP B Series | 2014 onward | Confirm the B-Series designation; earlier A-Series engines can require another cylinder. |
Different cylinder examples: the guide specifies HC6345-3 for many Mercury PRO XS single-engine models, HC5358-3 for Suzuki 115–140 HP four-strokes, and Tournament equipment for some high-power twin applications. Send your engine make, exact model, year, horsepower, number of engines, and engine center spacing through our Tech Support form if the application chart is unclear.
2027 Guide
Find the cylinder listed for your outboard
The 2027 Dometic SeaStar guide covers HC5345-3 and other front-mount cylinders. Use the finder to locate a chart entry, then read its notes and check your steering configuration before ordering.
Find your engine's guide entry
Engine details first; installation checks still apply.
The tables below include every engine row in the guide's single, twin and PRO front-mount application charts.
Open full 2027 selection guide (PDF)Single outboards
58 engine entries, 2027 Dometic guide pp. 3-13 to 3-14.
Cox Marine1 entries
| Year | Engine / model | Cylinder | Guide notes |
|---|---|---|---|
| 2022–DATE | 300–350 HP Diesel | HC5358-3 | — |
Honda10 entries
| Year | Engine / model | Cylinder | Guide notes |
|---|---|---|---|
| 1996–DATE | 60–90 HP 4-Stroke | HC5345-3 | — |
| 1998–2009 | 115–130 HP 4-Stroke | HC5347-3 | — |
| 1998–DATE | 30–50 HP 4-Stroke | HC5345-3 | See note 1 |
| 2003–2022 | 200–250 4-Stroke | HC5445-3 | See note 8 |
| 2003–DATE | 135 HP 4-Stroke | HC5345-3 | — |
| 2004–DATE | 150 HP 4-Stroke | HC5345-3 | See note 4 |
| 2011–DATE | 115HP 4-Stroke | HC5345-3 | — |
| 2015–DATE | 100 HP 4-Stroke | HC5345-3 | — |
| 2023–DATE | 200–250 4-Stroke | HC5345-3 | See note 8 |
| 2023–DATE | 350HP 4-stroke | HC5345-3 | See note 7 |
Johnson/Evinrude6 entries
| Year | Engine / model | Cylinder | Guide notes |
|---|---|---|---|
| 1991–DATE | 40–300 HP 2-Stroke | HC5345-3 | Inc. ETech engines |
| 1997–DATE | 75–300 HP Ficht | HC5345-3 | — |
| 1998–DATE | 40–140 HP 4-Stroke | HC5358-3 | See note 1 |
| 2000–2003 | 115 HP Ficht | HC5358-3 | See note 1 |
| 2002–DATE | 200–225 HP 4-Stroke | HC5345-3 | — |
| 2007–DATE | 3.3L V6 200–250HP | HC5345-3 | Inc. H.O. models |
Mercury11 entries
| Year | Engine / model | Cylinder | Guide notes |
|---|---|---|---|
| 1989–DATE | 75–300 HP 2-Stroke | HC5345-3 | — |
| 1998–2007 | 40–60 HP 4-Stroke | HC5348-3 | See note 1 |
| 2003–DATE | 150–200 HP Verado | HC6345-3 | — |
| 2004–DATE | 115 HP PRO XS | HC5345-3 | — |
| 2004–DATE | 150–300 HP PRO XS | HC6345-3 | — |
| 2008–DATE | 40–60 HP 4-Stroke | HC5345-3 | See note 1 |
| 2017–DATE | 175–225 HP 3.4L V6 4-Stroke | HC5345-3 | See note 3 |
| 2018–DATE | 250–300 HP 4.6L V8 4-Stroke | HC5345-3 | See note 3 |
| 2022–DATE | 60R HP 4-Stroke | HC5345-3 | See note 1 |
| 2022–DATE | 150R HP 4-Stroke | HC5345-3 | — |
| 2022–DATE | 200–300R HP 4-Stroke | HC6345-3 | — |
Oxe2 entries
Selva4 entries
Suzuki8 entries
| Year | Engine / model | Cylinder | Guide notes |
|---|---|---|---|
| 1986–2000 | 100 HP 2-Stroke | HC5345-3 | — |
| 1986–2002 | 115–140 HP 2-Stroke | HC5345-3 | NOT 1996 |
| 1998–DATE | 115–140 HP 4-Stroke inc. A Series | HC5358-3 | See note 1 |
| 2020–DATE | 115–140 HP 4-Stroke inc. B Series | HC5358-3 | See note 1, 7 |
| 1986–2013 | 150–225 HP 2 and 4-Stroke | HC5345-3 | — |
| 2004–DATE | 200–300 HP V6 | HC5358-3 | See note 7 |
| 2013–DATE | 150–200 HP 4 Cylinder | HC5345-3 | — |
| 2017–DATE | 300–350 HP Dual Prop 4.4L | HC5358-3 | See note 5, 7 |
Tohatsu6 entries
| Year | Engine / model | Cylinder | Guide notes |
|---|---|---|---|
| 1990–DATE | 40–140 HP 2-Stroke | HC5345-3 | — |
| 2014–DATE | 60–150 HP 4-Stroke BFT | HC5345-3 | — |
| 2014–2022 | 200–250 HP 4-Stroke BFT | HC5445-3 | See note 8 |
| 2023–DATE | 200–250 HP 4 Stroke BFT | HC5345-3 | — |
| 2023–DATE | 40–60 HP 4-Stroke MFS | HC5348-3 | See note 1 |
| 2023–DATE | 75–150 HP 4-Stroke MFS | HC5345-3 | Tohatsu tiller bolt 3E0-84917-0 |
Yamaha10 entries
| Year | Engine / model | Cylinder | Guide notes |
|---|---|---|---|
| 1990–2003 | 40–90 HP 2-Stroke | HC5345-3 | See note 1 |
| 1986–DATE | 100–300 HP 2-Stroke | HC5345-3 | — |
| 1997–DATE | 80–250 HP 4-Stroke | HC5345-3 | — |
| 2000–DATE | 150–300 HPDI | HC5345-3 | See note 2 |
| 2003–DATE | 25–70 HP 4-Stroke | HC5348-3 | See note 1 |
| 2007–DATE | 200–300 HP 4.2L V6 4-Stroke | HC5345-3 | See note 4, 6 |
| 2007–DATE | 300–350 HP 5.3V8 | HC5345-3 | See note 4, 7 |
| 2011–2014 | 90–115 HP inc. A Series | HC5358-3 | — |
| 2012–DATE | 150–200 HP 2.8L 4 Cylinder | HC5345-3 | — |
| 2014–DATE | 75–115 HP inc. B Series | HC5345-3 | — |
Twin outboards
56 engine entries, 2027 Dometic guide pp. 3-15 to 3-16.
Cox Marine1 entries
| Year | Engine / model | Cylinder | One cylinder tie bar | Two cylinder tie bar | Guide notes |
|---|---|---|---|---|---|
| 2022–DATE | 300–350 HP Diesel | HC5358-3 | N/A | HA5520 | See note 7 |
Honda10 entries
| Year | Engine / model | Cylinder | One cylinder tie bar | Two cylinder tie bar | Guide notes |
|---|---|---|---|---|---|
| 1996–DATE | 60–90 HP 4-Stroke | HC5345-3 | HO6001 | HO6002 | See note 4 |
| 1998–2009 | 115–130 HP 4-Stroke | HC5347-3 | N/A | N/A | — |
| 1998–DATE | 30–50 HP 4-Stroke | HC5345-3 | HO6001 | HO6002 | See note 2 |
| 2001–DATE | 150 HP 4-Stroke | HC5345-3 | HO6001 | HO6002 | See note 6 |
| 2003–DATE | 135 HP 4-Stroke | HC5345-3 | HO6003 | HO6002 | — |
| 2011–DATE | 115HP 4-Stroke | HC5345-3 | HO6003 | HO6002 | — |
| 2015–DATE | 100 HP 4-Stroke | HC5345-3 | HO6003 | HO6002 | See note 5 |
| 2001–2022 | 200–250 HP 4-Stroke | HC5445-3 | HO6001 | HO6002 | See note 9, 10 |
| 2023–DATE | 200–300 HP 4-Stroke | HC5345-3 | HO6001 | HO6002 | See note 9, 10 |
| 2023–DATE | 350 HP 4-Stroke | Tournament review | — | — | Must use Tournament cylinders. Refer to page 3-22. |
Johnson/Evinrude7 entries
| Year | Engine / model | Cylinder | One cylinder tie bar | Two cylinder tie bar | Guide notes |
|---|---|---|---|---|---|
| 1991–DATE | 40–300 HP 2-Stroke | HC5345-3 | HO6003 | HO6002 | Inc. ETech engines |
| 1997–DATE | 75–300HP Ficht | HC5345-3 | HO6003 | HO6002 | — |
| 1998–DATE | 40–140 HP 4-Stroke | HC5358-3 | HO6003 | HO6002 | See note 2 |
| 2000–2003 | 115HP Ficht | HC5358-3 | HO6003 | HO6002 | See note 2 |
| 2002–DATE | 200–225 HP 4-Stroke | HC5345-3 | HO6003 | HO6002 | — |
| 2005–DATE | 250 HP DPX Vindicator | HC5348-3 | HO6003 | HO6002 | — |
| 2007–DATE | 200–250 HP 3.3L V6 | HC5345-3 | HO6003 | HO6002 | Inc. H.O. models |
Mercury15 entries
| Year | Engine / model | Cylinder | One cylinder tie bar | Two cylinder tie bar | Guide notes |
|---|---|---|---|---|---|
| 1989–DATE | 75–300 HP 2-Stroke | HC5345-3 | HO6001 | HO6002 | See note 4 |
| 1996–DATE | 75–200 HP 2 and 4-Stroke | HC5345-3 | HO6001 | HO6002 | See note 6 |
| 1998–2007 | 40–60 HP 2 and 4-Stroke | HC5348-3 | HO6001 | HO6002 | See note 2 |
| 2008–DATE | 40–60 HP 4-Stroke | HC5345-3 | HO6001 | HO6002 | See note 2 |
| 2002–2003 | 225 HP 4-Stroke | HC5358-3 | HO6001 | HO6002 | See note 1 |
| 2004–DATE | 150–200 HP Verado | HC5345-3 | HO6001 | HO6002 | — |
| 2003–DATE | 150–200 HP PRO XS | HC6345-3 | HA5522 | HA5520 | See note 7 |
| 2003–DATE | 250–300 HP PRO XS | Tournament review | — | — | Must use Tournament cylinders. Refer to page 3-22. |
| 2016–DATE | 115–150 HP 2.1/3.0L 4-Stroke | HC5345-3 | HO6001EM | HO6002 | See note 10 |
| 2017–DATE | 175–225 HP 3.4L V6 4-Stroke | HC5345-3 | HO6001EM | HO6002 | See note 10 |
| 2018–DATE | 250–300 HP 4.6L V8 4-Stroke | HC5358-3 | HA5522 | HA5520 | See note 7 |
| 2022–DATE | 60R HP | HC5345-3 | HO6001EM | HO6002 | See note 10 |
| 2022–DATE | 150R HP | HC5345-3 | HO6001EM | HO6002 | See note 10 |
| 2022–DATE | 200R HP | HC6345-3 | HO6001EM | HO6002 | See note 10 |
| 2022–DATE | 250R –300R HP | Tournament review | — | — | Must use Tournament cylinders. Refer to page 3-22. See note 8 |
Oxe2 entries
| Year | Engine / model | Cylinder | One cylinder tie bar | Two cylinder tie bar | Guide notes |
|---|---|---|---|---|---|
| 2017–DATE | 200 HP Diesel l4 2.4L | Tournament review | — | — | Must use Tournament cylinders. Refer to page 3-22. |
| 2020–DATE | 300–350 HP Diesel | Tournament review | — | — | Must use Tournament cylinders. Refer to page 3-22. |
Suzuki5 entries
| Year | Engine / model | Cylinder | One cylinder tie bar | Two cylinder tie bar | Guide notes |
|---|---|---|---|---|---|
| 2002–DATE | 90–140 HP 4-Stroke inc. A Series | HC5358-3 | HO6003 | HO6002 | See note 2 |
| 2013–DATE | 150–200 HP 4-Stroke 4 Cylinder | HC5345-3 | HO6001 | HO6002 | — |
| 2004–DATE | 200–300 HP 3.6 4.0L V6 | HC5345-3 | HO6001 | HO6002 | See note 10, 11 |
| 2017–DATE | 300–350 HP 4.4L V6 | Tournament review | — | — | Must use two Tournament cylinders. Refer to page 3-22. See notes 8, 11. |
| 2020–DATE | 115–140 HP B Series | Tournament review | — | — | Must use two Tournament cylinders. Refer to page 3-22. |
Tohatsu6 entries
| Year | Engine / model | Cylinder | One cylinder tie bar | Two cylinder tie bar | Guide notes |
|---|---|---|---|---|---|
| 1990–DATE | 40–140 HP 2-Stroke | HC5345-3 | N/A | N/A | — |
| 2014–DATE | 60–150 HP 4-Stroke BFT | HC5345-3 | HO6003 | HO6002 | — |
| 2014–2022 | 200–250 HP 4-Stroke BFT | HC5445-3 | HO6001 | HO6002 | See note 9, 10 |
| 2023–DATE | 200–300 HP 4 Stroke BFT | HC5345-3 | HO6001 | HO6002 | See note 10 |
| 2023–DATE | 40–60 HP 4-Stroke MFS | HC5348-3 | Note >> | Note >> | Contact tech. support |
| 2023–DATE | 75–140 HP 4-Stroke MFS | HC5345-3 | Note >> | Note >> | Contact tech. support |
Yamaha10 entries
| Year | Engine / model | Cylinder | One cylinder tie bar | Two cylinder tie bar | Guide notes |
|---|---|---|---|---|---|
| 1990–2007 | 40–90 HP 2 -Stroke | HC5345-3 | HO6003 | HO6002 | — |
| 1986–DATE | 100–300 HP 2-Stroke | HC5345-3 | HO6001 | HO6002 | — |
| 2000–DATE | 150–300 HPDI | HC5345-3 | HO6001 | HO6002 | — |
| 2001–2003 | 80–250 HP 4-Stroke | HC5358-3 | HO6001 | HO6002 | See note 1 |
| 2003–DATE | 150–250 HP 3.3L | HC5358-3 | HO6001 | HO6002 | — |
| 2003–DATE | 25–70 HP 4-Stroke | HC5348-3 | HO6003 | HO6002 | See note 3, 4 |
| 2007–DATE | 200–300 HP 4.2L V6 4-Stroke | HC5345-3 | HO6001 | HO6002 | See note 10 |
| 2007–DATE | 300–350 HP 5.3V8 | Tournament review | — | — | Must use Tournament cylinders. Refer to page 3-22. |
| 2011–2014 | 90–115 HP inc. A Series | HC5358-3 | HO6003 | HO6002 | — |
| 2014–DATE | 75–115HP inc. B Series | HC5345-3 | HO6001 | HO6002 | — |
SeaStar PRO, single outboard
11 engine entries, 2027 Dometic guide pp. 3-19.
Honda1 entries
| Year | Engine / model | Cylinder | Guide notes |
|---|---|---|---|
| 2001–DATE | 150–350 HP 4-Stroke | HC6345-3 | HA5472 stroke limit kit must be installed on 200–250 HP 4-Stroke (pre-2023 only) |
Johnson/Evinrude3 entries
Mercury1 entries
| Year | Engine / model | Cylinder | Guide notes |
|---|---|---|---|
| 1989–DATE | 150–300 HP 2-Stroke, 4-Stroke and XS engines, including 4.6L V8 | HC6345-3 | — |
Suzuki5 entries
Yamaha1 entries
| Year | Engine / model | Cylinder | Guide notes |
|---|---|---|---|
| 1986–DATE | 150–350 HP 2 and 4-Stroke | HC6345-3 | — |
Single chart note definitions
- 1. Spacer kit HO5090 required.
- 2. Spacer kit HP6033 required.
- 3. PRO XS must use HC6345-3.
- 4. HC5358-3 is an optional cylinder; slight interference may occur at full engine tilt.
- 5. Use PA1200-3HP Power Assist and HA5482 Optimus fluid.
- 6. HC5358-3 required when using SeaStar SmartStick.
- 7. Single engine application only. Refer to the twin guide for twins.
- 8. Cylinder revised mid-2022; contact Dometic technical support.
Twin chart note definitions
- 1. HC5345-3 is optional for single engines only; do not use it for this twin entry because interference may occur.
- 2. Spacer kit HO5090 required for each engine.
- 3. Spacer kit HO5090 required for each engine.
- 4. Minimum engine center distance is 27 in.
- 5. Customer-supplied stainless steel washer required beneath rod end.
- 6. Slight interference may occur with HO6001 tie bar; contact Dometic technical support.
- 7. Use the tie bar distance table on guide p. 3-13.
- 8. Use PA1200-3HP Power Assist and HA5482 Optimus fluid.
- 9. Cylinder revised mid-2022; contact Dometic technical support.
- 10. Aggressive-use tie bar and HA5522 kit may be used; see guide p. 3-13.
- 11. HC5345-3 mounts beneath the tiller arm.
When the guide calls for Tournament steering
Tournament cylinder and hardware selection
Several twin-engine chart rows direct you to Tournament steering. The separate configuration table lists HC6845 and, for Honda V6 or where stroke reduction is needed, HC6850. Cylinder quantity, hardware, engine spacing and tie bars depend on the engine and installation. Review guide pp. 3-22 to 3-24.
Integrated steering engines and installations with three or more outboards need their own system-specific guidance.
Specifications
| Brand | Dometic SeaStar |
|---|---|
| Part number | HC5345-3 |
| Type | Front-mount pivot cylinder for supported outboard hydraulic steering systems |
| Stroke | 8 in (203 mm) |
| Shaft diameter | 0.75 in (19 mm) |
| Cylinder fluid volume | 8.34 cu in (136.6 cc) |
| Cylinder hose fittings | Positionable stainless steel ORB elbows; 3/8-inch compression hose connection. Do not use NPT fittings in the -3 cylinder ports. |
| Approximate installed cylinder dimensions | 21.75 in across × 4.875 in deep × 2.625 in high (manual drawing; pivot-plate details vary by cylinder model) |
| Seal service kit | HS5157 (Dometic service-parts list) |
| HS/HTS code | 8412.21.0075 |
| Country of origin | Canada (CA) |
| Supplier unit weight | 9.6 lb |
| Unit dimensions | 22.5 × 5 × 4 in |
Parts & Kits
Repair and replacement parts for the HC5345-3
The items below follow Dometic's front-mount cylinder service-parts diagram (Book 1.3, Revision L, page 34). Select the repair by the worn or damaged component. A seal-kit replacement does not replace an internal center seal or a damaged pivot plate.
| Part | What it supplies | When to use it |
|---|---|---|
| HS5157 seal kit with wrench | Two screw-in end glands, pin wrench and guide tool. | Start here for leaking cylinder end glands. Dometic states the center/internal seal is not included. |
| HS5167 seal kit without wrench | Alternate front-mount gland kit without the pin wrench. | Choose only if you already have the proper wrench; SeaTech's HS5167 page lists HC5345-3 as compatible. |
| HF5548 bleeder fittings | Two bleeder nipples per kit; the manual says covers are not included. | Replace damaged bleeder fittings used when purging the cylinder. |
| HP6014 support bracket kit | Support brackets, support rod and hardware for the standard front-mount cylinder. | Repair damaged support hardware. The PRO-only HP6101/HP6111 parts are not the standard HC5345-3 support kit. |
| HF6004 ORB elbow fittings | Positionable hose elbows for -3 cylinder ORB ports. | Replace damaged hose-side elbows. Do not install an older NPT elbow such as HF6145 in these ports. |
| HA5829 tiller bushing kit | Engine-side tiller bushing and high-strength tiller bolt. | Replace worn bushing or mounting hardware after checking the engine-specific instructions. |
| HP6033 spacer / adjusting-nut kit | Spacer and adjusting-nut components shown in the cylinder service diagram. | For the relevant cylinder support hardware, or engine applications that specifically call for HP6033. |
| HF6005 ORB hose tee | Hose tee fitting shown as an optional service fitting in the manual. | Only for a hose layout that specifies the tee; not a routine replacement for the standard elbows. |
| HA5477 grounding strap | Grounding strap for the cylinder assembly. | Replace a missing or damaged strap and follow the manual's attachment procedure. |
The pivot mount plate has no separately listed service part number. Dometic says to replace the cylinder if that plate is damaged. For a repair you would rather have done professionally, see our SeaStar cylinder rebuild service.
Engine- and configuration-specific hardware
These parts are selected by the 2027 engine application chart and installation, not included with every HC5345-3 order.
| Part | Application |
|---|---|
| HO5090 | Engine spacer kit on guide rows marked note 1 (single) or note 2 (twin); one per engine where specified. |
| HA5822 | High-strength tiller bolt required for engines above 300 HP and the applications described by Dometic. Verify whether the installed cylinder already includes the correct bolt. |
| HO6001 | Single-cylinder twin-engine tie bar where listed in the twin chart. |
| HO6001EM | End-mount single-cylinder tie bar for listed Mercury twin applications. |
| HO6002 | Two-cylinder twin-engine tie bar where listed in the twin chart. |
| HO6003 | Single-cylinder twin-engine tie bar where listed for Honda, Johnson/Evinrude, Tohatsu, or Yamaha. |
| HA5522 | Hardware kit for the selected aggressive-use tie-bar setup; verify guide configuration and center spacing. |
Steering kits that include the HC5345-3
These three SeaTech kit listings explicitly identify the HC5345-3 cylinder. Select the helm style and hose option on the individual kit page; the manufacturer's base HK6400-4 package does not contain a fixed-length hose pair.
| Kit | Helm and listed contents | Hose selection |
|---|---|---|
| HK6400-4 standard front mount | HH5271-4 1.7 cu in helm, HC5345-3 and two quarts of SeaStar steering fluid. | Choose a suitable hose pair separately using SeaTech's kit-page option; the base Dometic kit excludes hoses. |
| HK6400TC-4 Classic Tilt | HH6541-4 1.7 cu in Classic Tilt helm, HC5345-3 and two quarts of SeaStar steering fluid. | SeaTech's listing offers a selectable hose length and fitting upgrade; check the configured kit choice. |
| HK6400TS-4 Sport Tilt | HH6191-4 1.7 cu in Sport Tilt helm, HC5345-3 and two quarts of SeaStar steering fluid. | SeaTech's listing offers a selectable hose length and fitting upgrade; check the configured kit choice. |
Installation
Plan the entire steering system
- Use the 2027 selection guide to confirm the engine's exact application, normal-use limits, and any spacer, tiller-bolt, or tie-bar requirement. Select the helm and SeaStar steering hoses for that configuration.
- Check the splashwell and installation drawing in Book 1.3 before ordering. Its minimum single-engine splashwell dimensions are 22 in across, 6 in fore-aft, and 5 in in the third dimension shown in the diagram; twin-engine installations require a different width. The cylinder's installed dimensions are not the entire clearance envelope.
- Install the positionable ORB fittings and support hardware exactly as the cylinder manual specifies. Do not install an NPT elbow in the -3 ports or apply pipe sealant to an ORB or hose-side connection.
- With the engine tilted both down and up, check steering travel, hose movement, and interference at the transom, splashwell, engine, and any jackplate position. Fill, bleed, and perform the oil-level and system checks in the manual before use.
Dometic's installation manual includes torque values, mounting illustrations, grounding-strap steps, hose routing, fill-and-purge instructions, maintenance, and troubleshooting. Keep the manual with the boat and follow it for the actual engine installation.
FAQs
Does HC5345-3 fit every outboard up to 350 HP?
No. The 350 HP figure is a normal-use system limit for a single-engine configuration. Engine make, model, year, tiller arm, mounting space, and boat use determine the cylinder choice. Dometic specifies different cylinders for some engines within that power range.
Can I use it on twin outboards?
Yes, where Dometic's twin-engine chart specifies HC5345-3 and the correct tie bar and hardware are selected. Engine spacing, rotation, power, and interference affect the choice. Some twin applications use a different cylinder or Tournament setup.
Can I reuse fittings from my older HC5345 cylinder?
Do not reuse an NPT fitting in the HC5345-3 ports. This -3 cylinder uses ORB fittings; threading an NPT fitting into the port can damage the cylinder. Verify the existing hose ends and select the proper ORB fitting arrangement.
Which service parts match this cylinder?
The HS5157 kit includes the pin wrench; HS5167 is the alternate gland kit without one. The Parts & Kits tab lists the service-diagram parts, hardware and purpose of each. The center/internal seal is not included in HS5157.
Does the cylinder include a helm and hoses?
No. This is the cylinder listing. SeaTech also lists three complete steering kits containing HC5345-3 with standard, Classic Tilt or Sport Tilt helms. Hoses are not part of the base Dometic HK6400-4 box; select the hose option on the kit listing or choose a separate hose pair to fit your boat.
Resources
Dometic / SeaStar PDFs
- Dometic Marine Steering Selection Guide 2027 (PDF): front-mount system limits on page 3-9, engine application charts on pages 3-13 to 3-16, cylinder specifications in section 7, and fitting guidance in section 9.
- SeaStar Front Mount Cylinder Installation and Owner's Manual, Book 1.3, Revision L (PDF): fitment figures, splashwell dimensions, installation, bleeding, maintenance, and the HC5345-3 service-parts diagram.
- Dometic SeaStar Outboard Steering Cylinder technical sheet (PDF): HC5345-3 shaft, stroke, volume, seal kit, and system-application overview.
For the complete purchasable service-parts list, engine-specific hardware and steering kits, open the Parts & Kits tab above.
Need help with an engine application or replacement? Send the exact engine model, year, and current cylinder number.
