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Heavy Duty Suredrive™ Coupling for Borg Warner & ZF 220A Transmissions


We consider the HD Suredrive coupling to be a FOREVER coupling. Barring improper installation and/or salt water damage, this coupling comes with a 5 year / unlimited hours full warranty.

Product Documentation


Shipping Weight

25 lbs

Shipping Dimensions 16 × 16 × 4 in

In stock



Many marine transmissions rely on a floating spline coupling arrangement to transfer power from the engine flywheel to the transmission.

The relatively short spline on the transmission input shaft, coupled with the spline in the drive plate, is the weakest link in your boat’s drive system. This spline arrangement is highly intolerant to poor alignment and is very susceptible to wear from constant changes in engine output (e.g. commercial fishboats operating at low RPM), vibration and inconsistent off-on loading conditions.

The Suredrive™ is designed to eliminate this weak link by locking a female center spline hub onto your existing transmission input shaft.


It is not necessary to replace your input shaft even if the spline is worn. The Suredrive™ centre spline hub will lock onto even the most worn spline surfaces.

“Do not let a salesperson sell you an input shaft if yours is worn, you only need 20% remaining on your spline for a Suredrive™ to engage and lock 100%.”

Don’t let the noise of damper plate failure scare your fish away. Durable elastomers (rubber inserts) are installed at the perimeter of the inner spider drive to aid in dampening engine vibration and torsional forces, thereby providing a much quieter drive system.

Finally, the outer spider drive is bolted onto the engine flywheel. The centre sockets of the outer spider engage the inner spider drive with the rubber inserts effectively cushioning the mating surfaces.


  • ECONOMY – Eliminates high cost, high wear components and downtime related to your drive system.
  • SAFETY – Infinitely stronger than traditional drive plates, the Suredrive™ gets you home every time.
  • QUIET OPERATION – The Suredrive™ dampens noise and vibration that is transmitted along the prop shaft and into the water, particularly in the low R.P.M. range.
  • INSTALLATION – It’s simple & it’s easy! If you can operate a torque wrench you can install your own Suredrive™. See installation instructions here.



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1. Does the Suredrive™ fit my transmission? What is your transmission?
Refer to Specs. or our Compatability chart. 

2. Do the rubber blocks wear out very fast? How long do they last?
It really depends on the application, variables such as extreme misalignment, continuous low rpm operations and/or improper installation. i.e. if rubbers not completely positioned into outer drive receiving pockets can all contribute to premature wear. We recommend that all rubber blocks be changed at your regular transmission service. We have one customer that has 4 Suredrive™ in 2 fishing boats (twin) and has over 28,000 hours on the original set of rubbers and he hasn’t had to change them. 

3. What is the minimum amount of splines need to mount the Suredrive™ to the input shaft?
The Suredrive™ can be mounted with as little as 20% of the splines left. 

4. What is the Suredrive™ made of? 
The inner and outer drives are cast from high quality ductile iron or quality steel. The center spline hub is machined from 4140 high nickel steel so it retains it’s shape upon removal from the inner spider drive assembly (ductile iron is too soft). Therefore the hub would be very difficult to remove from the input shaft as well as lose it’s circumference reducing capabilities upon reinstallation. 

5. The Suredrive™ seems to be heavier than the traditional drive plate that I have been using, is that O.K.?
The design of the Suredrive™ makes it heavier than traditional drive plates. The added weight helps to increase the flywheel mass which helps reduce torsional vibration and permits a much smoother operation at a lower idling rpm. 

6. Why would I spend more money on a Suredrive™ when I can buy a traditional drive plate for 1/2 the price? 
If you look at the cost of replacing a drive plate 1-2 times a year and eventually changing the transmission input shaft, (total cost can be up to $2300) gasket kit, labor for installation, safety factor, (The Suredrive™ always remains engaged) as well as the cost of down time of your vessel and compare it to the cost of a Suredrive™, I think the decision becomes clear. 

7. The Vulcan drive coupling has a better torsional vibration dampening system than the Suredrive™ why should I buy a Suredrive™?
Yes, the Vulcan drive coupling has a greater torsional absorption than the Suredrive™, but it still has the problem of premature spline wear. The only product that you will find that will correct the problem is the Suredrive™.