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Velvet drive ignorance

Printed From: CorrectCraftFan.com
Category: General Correct Craft Discussion
Forum Name: General Discussion
Forum Discription: Anything Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=6070
Printed Date: May-29-2024 at 7:56pm


Topic: Velvet drive ignorance
Posted By: Justin131313
Subject: Velvet drive ignorance
Date Posted: March-20-2007 at 6:33pm
O.K. here goes an attempt at the stupid question of the week award. I am just very curious about how the velvet drive works in my 85 nautique. It works so much better than other old boats Ive driven. No clunking into gear, smooth and solid. Does anyone know where I could see an expanded view of all of the parts. Or does anyone have a pic of the inside of one, or a disassembled one. Obviously there is a gearbox that engages an extra gear or something for reverse, but the smoothness? It feels like it has a torque converter similar to an automatic transmission. Does it? I am new.

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http://www.correctcraftfan.com/diaries/details.asp?ID=1807&sort=&pagenum=2&yrstart=1985&yrend=1985 - My 85 SN



Replies:
Posted By: Justin131313
Date Posted: March-20-2007 at 6:44pm
nevermind, found it in the reference section.

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http://www.correctcraftfan.com/diaries/details.asp?ID=1807&sort=&pagenum=2&yrstart=1985&yrend=1985 - My 85 SN


Posted By: eric lavine
Date Posted: March-21-2007 at 7:48am
Now you know why they call it a velvet drive...
it does not have a converter the prop more or less in a way is the converter, a converter is a hydraulic connection on cars.
a converter acts like a clutch as it does on a stick shift car, the reason you dont need a converter on a boat is that that the prop turns unhindered when put into gear and will not stall the engine.
reverse goes through a set of planetaries,(a set of gears inside of a sun gear) which allows it to reverse, the whine you hear in reverse are the planetary gears spinning aproximately 5 times engine speed and the helical cut on the gears cause the whine

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"the things you own will start to own you"


Posted By: backfoot100
Date Posted: March-21-2007 at 9:14am
Eric, thanks for that explanation. I've been wondering why most tranny's have that whine in reverse ever since I first heard it.

I have to agree with Justin131313 about my tranny. It's so smooth, never a hint of a slip, no clunks, grinding, or whining(in forward anyway). It seems to just keep going effortlessly and all I do is change the fluid and when I do that, the fluid looks like it was just changed yesterday. Yet I hear horror stories from others about the problems that they seem to have constantly with their tranny's. I know from other posts that the alignment has a lot to do with that. Is that the only reason for these issues from others or is there something else that can cause problems? Of course, assuming that they change the fluid regularly. Some others I've seen seem to run fine but they're noisy as hell. They have a terrible whine in forward and even worse in reverse. Do I just have a good one with exceptional alignment (I've never checked my alignment) or am I just good at dodging bullets?



Posted By: 8122pbrainard
Date Posted: March-21-2007 at 9:23am
100, I think allot has to do with who's transmission it is. I seem to get the idea from Eric that if it isn't a B/W then there are more problems. I think you should take the time and check your alignment.

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/diaries/details.asp?ID=1622" rel="nofollow -

54 Atom

/diaries/details.asp?ID=2179" rel="nofollow - 77 Tique

64 X55 Dunphy

Keep it original, Pete
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Posted By: David F
Date Posted: March-21-2007 at 10:16am
Originally posted by eric lavine eric lavine wrote:


reverse goes through a set of planetaries,(a set of gears inside of a sun gear) which allows it to reverse, the whine you hear in reverse are the planetary gears spinning aproximately 5 times engine speed and the helical cut on the gears cause the whine


I once had a BMW with a V-12 engine. The starter motor gave out and I opened it up to see what was wrong. I was surprised to find a planetary gear set, but then understood why it was there. The gear set multiplied the torque of the very small starter motor(small to fit in a very tight space) which made it possible to spin the 5.0L V-12 engine. It also explained the very unusual noise that the starter motor makes on all BMW V-12's...sounds like a chain saw cutting through a tree (whine).

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Posted By: eric lavine
Date Posted: March-21-2007 at 10:25am
Paragons use spur cut gears (straight teeth) which makes the planetary very noisey, if you notice on older cars(manual transmission) when you put them in reverse and back up you'll hear them whine, this is due to spur cut gears and also they will grind when shifted because of no synchros on the gear

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"the things you own will start to own you"


Posted By: hspore
Date Posted: March-21-2007 at 10:48am
Eric, with your service hat taken off, in reality, after how many hours should you change the tranny fluid in the velvet drive?
I was told 50-75 unless you do a lot of forward/reverse aggressive driving/skiing.

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Heath


Posted By: JoeinNY
Date Posted: March-21-2007 at 10:49am
The smoothness of the velvet drive once I got my first inboard was a massive surprise to me and all my fellow skiers who were raised on outboards and i/os. We have replaced our old "In Gear" shout to the skier/boarder with the somewhat longer but much more fun "Velvet Drive Engaged". I am sure there are people all along the shores of owasco lake that wonder what the heck that means....
-Joe.

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http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001
1967 Mustang 302 "Decoy"
http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video


Posted By: eric lavine
Date Posted: March-21-2007 at 11:50am
Heath, once a season is a good routine, there are guys out there that never change it and those are the guys i like. during winter along with winterizing I recommend filling the trans to the very top, doing this keeps the seals oiled and prevents a rust line inside the case, of coarse drain it completely in the spring and add fresh. there is no reason the transmission shoulnt last 25 years if maintained properly and this includes alignment

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"the things you own will start to own you"


Posted By: fixitjim
Date Posted: April-18-2007 at 3:08pm
I have been inspired to change my transmission fluid this weekend. I have a 93 Ski Nautique and have never changed the fluid. I have only about 400 hours and it runs perfectly but as you say Eric, you love people like me. I never knew it was so important until reading all this information here! I guess I have been very lucky. Thanks for all the great, helpful information on this site.


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fixitjim


Posted By: eric lavine
Date Posted: April-18-2007 at 4:19pm
im putting myself right out of business....lol   eric

Dont worry, for every one guy on this site there is about 1000 other guys with these trannies, those are the ones I prey on

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"the things you own will start to own you"



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