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rjrendemd · 05-01-2009, 15:59

I spoke to a new boat agent who was extolling the virtues of a v drive over both a shaft drive and a sail drive. Excuse my ignorance but I had never heard of it. How do they work, are they reliable and what are the pros and cons of a v drive? I had no problems with my shaft drive and I did not care for my sail drive. Do I want to consider one (or 2 if I buy a cat)?

Chief Engineer · 05-01-2009, 16:27

Vee Drives are used to conserve space The stuffing box is ususally under the transmission....There are no "virtues" to be extolled...if they aren't accessible
i.e. to tighten stuffing box they are a real liability. I have had a couple that have requires me to use 3 different wrenches to tighten stuffing boxes because there is no room to turn the packing nut.

"Boat agent extolling", around these here parts we call that Bravo Sierra

**skipmac** · 05-01-2009, 16:59

Second that reply on access limitations. Also as they have an additional gear in the V that transmits the full power of the motor so you have an additional, potential failure point.

Maine Sail · 05-01-2009, 17:17

A v-drive is nothing more than a transmission that allows the reversal of the engine in a boat for better interior room. There are no virtues and they are quite different from sail drives and very similar to a standard transmission.

V-drive installed find the stuffing box! (picture taken looking towards stern):

Here it is with the v-drive/transmission removed:

If you own a v-drive you should invest in a dripless shaft seal like the PSS!! Clearly your broker has no idea what he's talking about.v-drive = transmission that's all...

never monday · 05-01-2009, 17:37

V drives are a service nightmare

cal40john · 05-01-2009, 18:14

I've heard bad things about vdrives, but personally have had few problems. I sailed on a friends Cal 34 for 20 years and we never had to do anything to the vdrive. On the Cal 34 the vdrive is attached to the engine as in the above photos. Access to the shaft seal is poor on the 34 but can be accomplished.

Here's a remote vdrive that is found on Cal 40s. Access to the shaft seal is good. Thrust is taken by the remote vdrive instead of the engine. Vdrive is mounted on the boat so prop shaft alignment isn't dependent on engine movement. There is a U joint on the drive shaft and a CV joint in the input of the drive so my Yanmar on its soft mounts can bounce around up to +/- 3 degrees. Engine isn't in the middle of the cabin. No problems yet with my vdrive, 6 years with this boat.

As mentioned above, more mechanical stuff to fail, robs you of a little horsepower, more cooling hoses to route/fail.

I guess I wouldn't extoll a vdrive, but obviously I didn't walk away from a boat that had a vdrive in it. A vdrive's virtue is being able to place the engine in a more favorable spot, like not having to sit on the engine in the middle of the galley to prepare food, that only had a narrow walkway around it to get from one end of the boat to the other as I saw on one boat I was looking at buying that didn't have a vdrive.

John

This Cal 40 isn't my boat or web page.
From:
A Brief History… » The Restoration of a Cal 40

onestepcsy37 · 05-01-2009, 18:24

it's on a csy 37. perkins 4-108 with a borg warner transmission and then the walther v drive. given the design of my boat i don't think they could have done it any other way - unless they put in the engine in the middle of the galley.

i've had no problems with it, and the shaft seal is actually accessible enough that i can change and adjust the packing without getting too many cuts and scratches on my hands.

i found some paperwork on the boat that shows the p.o. had it rebuilt by walther in new jersey for one thousand dollars. that was sometime in the 1990's. i have heard that walther is very closefisted and won't supply parts to mechanics to fix their drives - they have to be sent to walther for rebuild. but it's only what i've heard so don't know if it's true or not.

we met a gulfstar 37 in the bahamas that had the exact same setup we have - perkins/borg warner/walther. but they had a problem. where the two shafts meet there is a bearing and the bearing had worn excessively and was coming through the casing. they couldn't run it above a low idle as it kept spitting out fluid. they were sailing it back to nassau to try to get it repaired. i wished them well but think they would be better advised to sail it straight back to fort lauderdale....

**David M** · 05-01-2009, 18:47

V-drives are nothing new. I saw them on a few Sea Scout boats back in the seventies. Some of these boats were from WW2. Its an old idea being rehashed as something new.

SkiprJohn · 05-01-2009, 20:28

Velvet Drive transmissions have a built in V-drive in some cases but mainly it is made to drive larger unit. Walther makes a good v-drive unit and I have an old Kassel v-drive here at the house. Of these three the best is the Velvet v-drive and the worst is the Kassel. Its noisy and shakes that's why I removed it.
Kind regards,
JohnL

SkiprJohn · 05-01-2009, 20:29

I think the velvet drive v-drive transmission unit weighs about 380lbs if I remember right.
JohnL

Chief Engineer · 05-01-2009, 20:38

Wow!!!!! If it weight 380 pounds....I must be SUPERMAN!!!!!!!!!!!!!!!!!!!!!!

That is well over twice my weight

always be wary of BIG sailboat mechanics HA HA HA

rjrendemd · 05-01-2009, 21:21

Gentleman,
Thank you for the replies and the pictures and the advice. Let me be the devil's advocate for a moment. Shaft drives excluded, is it better to have a packing nut that is difficult to service or have a large piece of aluminum hanging under your boat? I really don't want a saildrive but I don't care for a hot engine lying under the aft bunks of my cat.

cal40john · 05-01-2009, 22:10

Quote:

Originally Posted by rjrendemd

Gentleman,
Thank you for the replies and the pictures and the advice. Let me be the devil's advocate for a moment. Shaft drives excluded, is it better to have a packing nut that is difficult to service or have a large piece of aluminum hanging under your boat? I really don't want a saildrive but I don't care for a hot engine lying under the aft bunks of my cat.

Aluminum to corrode, rubber boots to tear, yearly servicing of the lower unit requiring haulouts every year (some brands), seals going bad on the lower unit getting water in the oil. Those are some of the complaints I've seen on this forum.

I've never sailed with a saildrive, so I don't know. Interesting, as some say vdrives are bad, I wonder how much I'm influenced by the familiarity of something (vdrives) that has been in the boats I've sailed since nearly the beginning of my sailing career, compared to something I've never seen close up, so being strange to me I consider a bad idea.

John