Lasdrop GEN II Shaft Seal Fits Shaft Diameter 3 1/4"
Lasdrop has been rated “Best” by PowerBoat Reports for good reason. Replacing the old-style stuffing box with the Lasdrop Gen II, Bellows, DrySeal and Elite has become the default for boat owners and marine yards worldwide. Installation is relatively simple. The Lasdrop Gen II maintains the quality that can make replacement a once-a-decade issue according to marine reviews. More than 25 years of experience went into the Gen II, and it shows.
The Lasdrop Shaft Seal offers exclusive features that make it the premier shaft seal on the market. The Gen II offers a unique ball-bearing drive system that allows the seal ring to "float" and remain in constant contact with the carbon graphite seal surface. The result is a seal that's impenetrable to water.
• The Gen II uses a 316-marine grade stainless steel spring to provide pressure to the seal surfaces. Together, the spring and seal ring rotate along with the shaft, and remain secured in the Clamp/Pressure housing.
• The Clamp/Pressure housing is secured to the shaft without the use of set screws preventing galling or damage to the shaft.
• Dual u-cup seals, which also rotate on the shaft, are seated inside of the seal ring and prevent the passage of water to this point.
• The friction ring assembly is constructed of a durable copolymer housing protecting the carbon graphite friction ring and also incorporating a water lubricated bearing maintaining correct alignment to the shaft.
• Each kit includes AWAB hose clamps that are made of 316 stainless steel with rolled band edges to eliminate risk of damage to the hose. The non-perforated band provides twice the tensile strength of a regular clamp.
- A = Shaft Size: 3.250"
- B = Stern Tube O.D. 4.500" thru 6.000"
- C = Seal Length: 7.400"
- D = Overall length Un-Compressed: 12.500 - 14.500""
- E = Pressure Housing: 5.250"
• Do not use oil or grease. During operation on a mechanical face seal, water hydroplanes between the seal surfaces for cooling and lubrication. This will distort the hydroplaning and will cause a spray or mist during operation.
• Be cautious not to scratch, chip or the like to the seal surfaces. This will also cause an interruption in the hydroplaning.
• Use liquid hand soap for ease of assembly.
• When any service is performed, it is recommended the vessel be out of the water.
• Do not exceed recommended compression. Orange (current) bellows model ½”, Black bellows ¾” and Generation II ¼”.
• Do not remove shaft from coupling or removal of engine while vessel is in water. This may lead to seal surfaces opening up.
• Do not tighten factory installed hose clamps on friction ring assembly. If needed contact factory.
• Do not remove or tighten hose barb in seals using OIN (Oil Impregnated Nylon, green in color) as a friction ring assembly. Contact factory.
• Periodically insure water injection is present during engine running at all speeds.
• When vessel is out of the water for any period of time, it is recommended seal is washed down with fresh water.
Q. How long should a seal last?
A. The DrySeal model will last three to five years before the inner lip seal must be changed. If a back-up seal is installed during the original installation, the seal can be easily installed without removing the shaft from the coupling. The “Original” Bellows and Generation II models will last as long as eight to ten years before servicing. Both models would most likely require refurbishing of the seal surfaces. In addition, the bellows on the “Original” model should also be inspected and replaced, if necessary. As in any part, they should be routinely inspected.
Q. Does a Lasdrop seal wear a shaft like the stuffing boxes do?
A. There is absolutely no shaft wear from the "Original" Bellows and Generation II. Because it is a lip-seal design, the "DrySeal" model produces very little wear on the shaft.
Q. How do I mount the unit if I have a flanged stern tube?
A. We offer flange adapters to accommodate any configuration of stern tube. We would need the bolt pattern.
Q. My existing stuffing box is not mounted with a hose.
A. On “rigid-type” stuffing boxes, it is possible to disassemble the front of the unit and turn it around, seal it so that the tube is protruding forward to permit the clamping of the seal.
Q. Does the seal need maintenance?
A. The seal is virtually maintenance-free. Like any part, the seal should be routinely inspected. If the vessel is in dry dock or not operated for a long period of time, it is good idea to wash down the seal with fresh water.
Q Is the seal difficult to install?
A. Installation is easy if you can access the area where the seal is installed. It is necessary to disassemble the shaft from the coupling. The shaft needs to be slid back far enough to remove the old stuffing box.
Q. Do I need water lubrication?
A. At hull speeds of 8 to 10 knots and above, a vacuum is created in the stern tube that draws the seawater used for cooling and lubrication. At slower hull speeds, no water lubrication is necessary. The supply hose can instead be used to purge the air out of the seal when the vessel is put back in the water. If there is no water injection, ensure there is water to the seals at all speeds. Lasdrop does, however, recommend water injection for all seals and speeds.
Q. What do I need for ordering?
A. Shaft size and the outside diameter of the stern tube. Make sure there is adequate clearance between the coupling and the end of the stern tube.