Saildrive or Not to Saildrive?

[Sid22]

We are currently looking for a cat in the 38-42 foot range and was wondering about drives. Is there a type of drive I should be looking for or a type I should run from? We plan on doing the Bahama/Carib thing and then maybe some extended cruising. I know nothing about cat drives so any info such as ease of maintenance, reliability, cost of service/parts, availability of said parts, etc. that makes one drive more desirable than another would be helpful. Thank you....Sid

[delmarrey]

Personally, I'd go shaft drive on anything over 40'. Saildrive's are like having an outboard in the water 100% of the time, lots of maintenance.

The only advantage I can see is engine room space or hull design. They can fit in where a shaft can not.

One of the things I don't like about small cat inboards is they are really hard to work on. One has to lay on their belly or stand on their head to do any bottom side or shaft log work.

[svcattales]

Originally Posted by Sid22

We are currently looking for a cat in the 38-42 foot range and was wondering about drives. Is there a type of drive I should be looking for or a type I should run from? We plan on doing the Bahama/Carib thing and then maybe some extended cruising. I know nothing about cat drives so any info such as ease of maintenance, reliability, cost of service/parts, availability of said parts, etc. that makes one drive more desirable than another would be helpful. Thank you....Sid

Sid, I have Volvo 120SD drives and after 4 years, I haven't had any problems. The book says to change the drive oil every 12 months which would normally mean a haulout, but after talking to many others, nobody does that. I can change about 60% of the oil by sucking it out the dip stick hole and I do that about once a year or more often if I'm putting a lot of hours on them. I went over 3 years between haulouts and the oil was very clean when I finally drained all of it.

The other maintenance item is to change the seals around the propeller shaft which I do at each haulout. That takes about 2 hrs each and you can make your own "special tools" to remove and replace seals. Not a big deal.

The major maintenance deal is to replace the large rubber "donuts" that seal the drive to the hull. This is an every 7 year change cycle and the job is pretty involved. I just changed mine for the first time and it involved separating the drive from the engine and moving the engine forward about 2 inches. The drive must be removed from the boat to install the new donuts. It took me 2 days to do the first one and 1 day to do the second one. These donuts are really important since they keep the ocean out of your boat. Make sure you ask how old the donuts are when buying a boat. If they "don't know" the donuts have a manufacture date on them which will be probably be within a year of installation.

I haven't had any problems getting parts, but they are expensive. For example, the "kit" to change the rubber donuts was over $300 each. The price on propeller seals wasn't too bad, but I don't remember what i paid.

Saildrives do have some nice advantages. You have no stuffing box so the bilge stays dry and there is no engine alignment to the drive shaft procedure which was a royal pain on my monohull.

Good luck with your boat shopping.

[jrd22]

I don't have a cat, but I do have a lot of experience with outdrives on power boats. They require a lot of maintenance and if you don't do it you can expect a short life. There is a magnet in the drain plug that collects the little pieces of metal in the oil, if you don't drain the oil you can't clean this plug and monitor how much metal there is. Also, the little Orings that seal the drain plug need to be replaced each time you change the oil or they can become brittle and crack, which can let seawater into the drive housing destroying all the bearings. I don't know what a saildrive costs, but the one on our power boat is 9K. There are also zincs that need to be replaced quite often because the housing of the drive is aluminum, and the shafts are stainless, so any electrolysis will attack the housing. I agree with Delmarrey, shaft drive is the way to go and it will be much cheaper in the long run.

[cal40john]

There's been some good discussion previously.


Following link provided by clicking on the Search button in the toolbar between New Posts and Quicklinks, then typing in saildrives in the Google Custom Search box.


saildrives - Google Search


John

[colemj]

It probably won't be a matter of which you prefer, but more a case of which types are available in that size range. 90% of models will be saildrives.

Personally, I wouldn't let the type of drive make the decision on the boat given all other important factors to consider.

Mark

[Antares]

I have had both shaft and a saildrive. Given a choice, I would consider how I would use the boat. Here in the NW, we can motor a lot. Summer, nice weather equals light to no wind. In use is where I really like my saildrive. It is quiter and smoother than the shaft drive in the previous boat. The maintenance is more time comsuming and expensive. Maintaining zincs is critical. Mine is a 120 Volvo of late 80s vintage and the prop has to come off to change the zinc. I haul to do it. I don't want to drop one of the many parts of the folding prop while diving. If it had a split zinc that could be serviced with the prop on I'd love it.

All in all for how I use a boat and where I go, I would not hesitate to go saildrive again.

[svcattales]

Originally Posted by colemj

It probably won't be a matter of which you prefer, but more a case of which types are available in that size range. 90% of models will be saildrives.

Personally, I wouldn't let the type of drive make the decision on the boat given all other important factors to consider.

Mark

I concur. It is much better to live with a saildrive than buy the wrong boat just because it has shaft drive.

[Firehoser75]

Sid,
I have a Volvo 120 (2004) saildrive. The zinc on the newer models are split, so they can be changed out in the water. Saildrives do have some advantages over shafts. With a saildrive the prop is at an angle of 90 degrees to the surface of the water (not so with a shaft drive) and this gives a more efficient thrust and allows for a reduction of prop walk in reverse and often better backing performance. They are often quieter, and usually have less vibration than do shafts. They also allow for a different engine placement in the boat than that required for a shaft set up (often allowing more internal usable space) and they don't leak sea water into the bilge allowing for a dry bilge with less smell. Like everything mechanical, they do require maintenance as many have already described. I have over 700 hours on mine so far, and no problems or concerns, but I am aware of the need to stay on top of the required maintenance.

Don't get me wrong, I am not saying everyone would be better off with a saildrive. The main reason boat builders install them is to save money, and to increase the space available to them inside the boat for "other purposes".
My main point is this: pick out the boat you like based on other considerations, and if it has a saildrive (or 2) don't let that alone deter you from your purchase. Just be well aware of the required maintenance. After all, you will have to maintain your engine(s) as well or else you will have big problems with them
Just my opinion,
Tom

[bene343]

if i were going offshore on a long cruise, my preference would be a shaft drive

[Kiwikat]

Not sure if I should admit this here or not but we have just had the saildrive on our Volvo30 serviced for the first time in 19 years of trouble free motoring (saildrive,that is). We have always had the engine serviced and regularly replace the zincs (which are hideously expensive for what they are) but never really gave a thought to the saildrive maintenance. The mechanic did not seem terribly surprised about this and commented that all was in good order.

Just my 2 cents worth
Cheers

[colemj]

Originally Posted by Antares

I If it had a split zinc that could be serviced with the prop on I'd love it.

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Mark

[svcattales]

Originally Posted by colemj

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Mark

What a great idea. I wish I saw this before my haulout a week ago... I would have put on the adaptors on both sides. The split zincs aren't cheap, but better to pay more for the zincs than paying for lost folding prop components.

[Sid22]

Thanks everyone for taking the time to express your opinions. I can now worry less about the drive system a particular boat might have. Next question on the list will be the age old comfort verses speed. Got a feeling that might open a can of worms!...I will post it in the proper forum here...Sid