explain transmissions
08-16-2007, 10:45 PM
#11
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There are put basically, some outdrives that have incorporated a shifting device, cone clutch or dog clutch or electric shifting devices and there are the others that have not incorporated them either due to design limitations or the power limitations of the above mentioned shifting methods.
Bravos use a cone clutch
Alpha's use a dog clutch
Merc outboards use a dog clutch
Volvo has cone clutch system
Yamaha had a different take on their shifting
Someone made an electric shift.
Others dives such as Mercury TRS, SSM#1,2,3,4,5,6 and 7 require a transmission to do the shifting for the outdrive.
Sea Power required a transmission. Inboard shaft drives require a transmission.
Arneson's require a transmission etc. etc. etc..
Everything has a power limit. Transmissions, dog clutches, cone clutches, electric shifting devices. Push the power up and you will find a weak link.
Bravos use a cone clutch
Alpha's use a dog clutch
Merc outboards use a dog clutch
Volvo has cone clutch system
Yamaha had a different take on their shifting
Someone made an electric shift.
Others dives such as Mercury TRS, SSM#1,2,3,4,5,6 and 7 require a transmission to do the shifting for the outdrive.
Sea Power required a transmission. Inboard shaft drives require a transmission.
Arneson's require a transmission etc. etc. etc..
Everything has a power limit. Transmissions, dog clutches, cone clutches, electric shifting devices. Push the power up and you will find a weak link.
Offshoreonly Advertiser
08-17-2007, 07:19 AM
#13
Definition of Crash Boxes
Keep in mind that for brevity I am simplyfing the definitions.
Marine transmissions that we are used to seeing, like a Borg Warner C72 for example, have clutch plates built in. The clutch plates are activated by hydraulic pressure to engage and disengage the drivetrain. This is what allows you to shift while the engines are running.
Crash boxes are similar to a manual automotive transmission much like a Muncie M21 in that they do not have internal clutches. (Although most marine transmissions only have one forward gear, although some have two) So if you try to shift your old SS 396 Chevelle into gear without using the clutch while the engine is running, you are going to hear some nasty grinding noises because you didn't use the clutch. So just as shifting without using the clutch is not feasible (someone is probably going to argue about speed shifting a car, but I'm just making a simple analogy), you can't shift a crashbox without shutting the engine off.
Although if you do shift and hurt your crash box, John Klumpian at Doller Offshore is excellent at rebuilding crashboxes, drives, and transmissions.
Barry
Marine transmissions that we are used to seeing, like a Borg Warner C72 for example, have clutch plates built in. The clutch plates are activated by hydraulic pressure to engage and disengage the drivetrain. This is what allows you to shift while the engines are running.
Crash boxes are similar to a manual automotive transmission much like a Muncie M21 in that they do not have internal clutches. (Although most marine transmissions only have one forward gear, although some have two) So if you try to shift your old SS 396 Chevelle into gear without using the clutch while the engine is running, you are going to hear some nasty grinding noises because you didn't use the clutch. So just as shifting without using the clutch is not feasible (someone is probably going to argue about speed shifting a car, but I'm just making a simple analogy), you can't shift a crashbox without shutting the engine off.
Although if you do shift and hurt your crash box, John Klumpian at Doller Offshore is excellent at rebuilding crashboxes, drives, and transmissions.
Barry
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Thanks, Barry
Driver - High's Fuel Your Journey Cigarette Racing Team #598
Thanks, Barry
Driver - High's Fuel Your Journey Cigarette Racing Team #598
08-17-2007, 07:25 AM
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A transmission with no means of smoothly engaging into gear, and no clutch to disengage it. Imagine you have a standard transmission in your car and you are trying to shift into reverse. Without a clutch you'd have to turn the engine off, shift it into gear, the start the engine again, and you're off and rolling. Crash boxes work the same way - no clutch, no synchros.
08-17-2007, 07:37 AM
#15
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is there a difference in the cone clutch trannie in the NXT drive vs their bravo drive set up. What makes the NXT handle more power vs the Bravo's. Thanks Jeff
08-17-2007, 08:19 AM
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We used to have an old sea-ray with an electric shift OMC. I'll never forget when it malfunctioned leaving us only with reverse and we had to back across the bay in 4ft seas and through the middle of a sailboat race.
08-17-2007, 10:11 AM
#18
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Thanks, but go ahead.. Im just trying to understand it better. This is whats on my next 4300, NXT drive and transom assembly with a #6 drive vs the nxt drive. I know there is 2 shafts vs 1, any other diferences, or tollerances. Thanks Jeff
