Hydrive OBKIT2 vs SeaStar Side Mount
Side-mount steering on the tilt tube - the classic cable-to-hydraulic upgrade
Replacing cable steering through the tilt tube is the most common hydraulic upgrade in Australia, and here the two brands aren't even sold the same way: OBKIT2 is a boxed kit; SeaStar's side-mount cylinder HC5370-3 is a component you build a system around, adding helm, hoses and fluid line by line. SeaStar's own catalogue offers no boxed side-mount kit.
Side by side
Published manufacturer figures only. Where a maker doesn't publish a number, the table says so.
How it's sold
Hydrive OBKIT2
Complete kit in one carton
SeaStar HC5370-3 (component build)
Cylinder only - helm, hoses and fluid specified and bought separately
Max power (single)
Hydrive OBKIT2
300 hp
SeaStar HC5370-3 (component build)
300 hp
Max power (twin, counter-rotating)
Hydrive OBKIT2
600 hp total
SeaStar HC5370-3 (component build)
600 hp total
Cylinder balance
Hydrive OBKIT2
Balanced (210T) - same turns both directions
SeaStar HC5370-3 (component build)
Unbalanced - 4.8 turns one way, 5.7 the other (1.7 helm)
Wheel turns lock-to-lock
Hydrive OBKIT2
Equal both directions (401 helm)
SeaStar HC5370-3 (component build)
4.8 / 5.7 (direction-dependent)
Power-assisted engines
Hydrive OBKIT2
Ask us - Hydrive publishes the 212T for power-assisted sterndrives; outboard power-steering fitment confirmed case by case
SeaStar HC5370-3 (component build)
HC5370-3 is SeaStar's only outboard cylinder cleared for engine power steering
Side clearance
Hydrive OBKIT2
540 mm (OBKIT3 single-ended: 330 mm)
SeaStar HC5370-3 (component build)
Set by cylinder and drag link geometry
Commercial use
Hydrive OBKIT2
Commercial-rated (Admiral series)
SeaStar HC5370-3 (component build)
None published
Warranty
Hydrive OBKIT2
2 years, commercial and leisure use alike
SeaStar HC5370-3 (component build)
2 years, limited to 1 year for commercial, rental or income-producing use (Dometic warranty, Form 340124 Rev B)
| Specification | Hydrive OBKIT2 | SeaStar HC5370-3 (component build) |
|---|---|---|
| How it's sold | Complete kit in one carton | Cylinder only - helm, hoses and fluid specified and bought separately |
| Max power (single) | 300 hp | 300 hp |
| Max power (twin, counter-rotating) | 600 hp total | 600 hp total |
| Cylinder balance | Balanced (210T) - same turns both directions | Unbalanced - 4.8 turns one way, 5.7 the other (1.7 helm) |
| Wheel turns lock-to-lock | Equal both directions (401 helm) | 4.8 / 5.7 (direction-dependent) |
| Power-assisted engines | Ask us - Hydrive publishes the 212T for power-assisted sterndrives; outboard power-steering fitment confirmed case by case | HC5370-3 is SeaStar's only outboard cylinder cleared for engine power steering |
| Side clearance | 540 mm (OBKIT3 single-ended: 330 mm) | Set by cylinder and drag link geometry |
| Commercial use | Commercial-rated (Admiral series) | None published |
| Warranty | 2 years, commercial and leisure use alike | 2 years, limited to 1 year for commercial, rental or income-producing use (Dometic warranty, Form 340124 Rev B) |
Whatever the manufacturer's warranty says, both brands also carry Australian Consumer Law guarantees that can't be excluded - and for goods under $100,000 those apply to business buyers too.
Where OBKIT2 wins
- A balanced cylinder: the 210T moves the same volume both directions, so the wheel feels identical port and starboard. SeaStar's side-mount is unbalanced - 4.8 turns one way, 5.7 the other.
- One part number, one box, done. Building the SeaStar equivalent means choosing a helm, a hose kit and fluid separately - and SeaStar's warranty wording warns against mixing in any non-SeaStar component.
- Screws onto the tilt tube where the cable ran, hoses stay stationary - and the commercial rating and 2-year commercial warranty come standard.
Credit where due
- Component buying suits a custom build - and HC5370-3 is SeaStar's cleared cylinder for engines with factory power steering.
- Matching ratings on paper: 300 hp single, 600 hp counter-rotating twins.
Our verdict
Same ratings, very different buying experience. OBKIT2 gives you a balanced cylinder and the whole system in one carton with a commercial warranty; the SeaStar route is a parts list. Unless there's a specific reason to build from components, the kit wins on simplicity, feel and support.
Questions we get asked
My splashwell is really tight - which side mount fits?
Hydrive's OBKIT3 uses the single-ended 210TSE cylinder and needs just 330 mm of side clearance - about 210 mm less than the balanced cylinder. Measure the well, send us a photo, and we'll confirm fit before you order.
Does a side mount work on a sterndrive too?
Yes - the same balanced 210T cylinder bolts to most sterndrive steering-cable brackets, sold as the OBKIT2 sterndrive variant, with Mercruiser- and Volvo-specific cylinders for those drives.
More comparisons
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