how big a problem is sd 50 cone clutch

[sowwaninii]

In light that virtually all entries in this discussion address problems encountered with the sd 50 cone clutch, we can't determine the extent of the overall problem because sampling bias. I'd like to hear from people who have had no problems with their sd 50. Would also be nice to know how many of these units were manufactutured.
Thanks

[Bean Counter]

We have two SD50's. 2200 hrs on each since new in 2011. Clutch cones have been lapped twice in 6 years DIY, at 900 hrs and 2100 hrs. Top drive shaft oil seal is another item, shafts replaced under warranty at 700 hrs. Top seals leaked again in mid 2016 (trapped dirt/grit causes a groove on the shaft at the sealing point) . At 1600 hrs, inserted high wear speedy sleeves on shafts and new seals, no further leaks (so far), again DIY. Apart from normal periodic maintenance no other issues.

[arsenelupiga]

2 sd 50, lapped at 500 hrs each - sent cone assembly to qualified mechanic. Now 700 hrs each and going strong. have all tools to do it myself when slipping comes up again. no leaks, no other issues.

[AB808]

Not that big Really. The sampling while interesting won't be conclusive. Perhaps if the responses are just from original owners, then only if also included is how the drive was maintained and operated. Otherwise, the responses are going to be random, or mostly negative- no one enjoys broken gear.
I'm a second owner, I re-lapped both when one began slipping at 1k hours. Since then no problem. The procedure wasn't difficult and there is an aftermarket improvement to replace the thrust washers with bearings to help maintain the clutch tolerance. I'll probably buy and install these if mine begins to slip again. I know lots more about how the clutch works, so I make sure I give it a chance to disengage from forward completely before shifting to reverse (by waiting a second or so in neutral). Certainly everything is a consideration, but I don't feel like it's a deal breaker for buying a particular boat.

[Cat White House]

The above lapping and maintenance advice is great. Add to that you should purchase a spare cone, ... and never let a mechanic keep the removed cone. Get it re-lapped until after nine lives.

[Timreyn]

I have a SD50 that is slipping. Starboard side of my Cat. I planned on trying to repair myself but ran out of time and had to return to the US. The guy who looks after our boat had the local Yanmar guy look at it and they intend to replace the cone with a new one when he hauls the boat in February. They said their was evidence of seawater in the outdrive, I did not observe a problem, and required seals replacing. This 2006 engine has 1358 hours on it. No prior problems I am told by the previous owner. I am a DIY always and a reasonably good mechanic so I will take the advice to keep the old cone, resurfaced, as a spare. Thanks

[meirriba]

Another issue us the oil change, that has to be done when boat is out of the water. So your sailing plans should align the haulout for maintenance/antifouling with the number of hours of the engine. At least roughly.

[Dulcesuenos]

Can't you buy the fix kits from Sv Panache that eliminates the slippage issue and other problems?
Post from them here with email info
http://www.cruisersforum.com/forums/...d.php?t=192693

[boom23]

I had one of the SD50s slipping on my ex Lagoon 450. I was in Tonga and there were no techs around. Another cruiser helped me lap the clutch cone. I would recommend you have the necessary tools and learn how to do it yourself. Do it when you get the first sign of slipping.

My next boat will not have saildrives. In my opinion, they are not good for serious cruising.

[kcj]

Originally Posted by boom23

I had one of the SD50s slipping on my ex Lagoon 450. I was in Tonga and there were no techs around. Another cruiser helped me lap the clutch cone. I would recommend you have the necessary tools and learn how to do it yourself. Do it when you get the first sign of slipping.

My next boat will not have saildrives. In my opinion, they are not good for serious cruising.

It’s not saildrives, it’s yanmar SDs. Never heard of Volvo SDs having this issue.
I have SD40s in my cat. At 4400hrs stb went from fine to useless in a snorkel stop...

Bought one of panache’s upgrade kits. What he said about tolerances made sense. And after installing it it makes more sense. He had responsive support and it Worked great, real solid engagement. (Btw we have to wait 500 hrs for the real answer ....)

What yanmar says about lapping cones being routine maintenance is bs—never heard of routine maintenance requiring a Dremel to cut a nut off.

The UK requires a few extra hours of filing and dremeling (in addition to the basic lapping) but appears to be a rock solid solution.

With or without the UK, I no longer fear the SD slippage. I just hope it doesn’t happen approaching hard objects......

[boom23]

Originally Posted by kcj

It’s not saildrives, it’s yanmar SDs. Never heard of Volvo SDs having this issue.

Not to change the topic but with a quick search about Volvo Saildrive Problems I found this: http://www.cruisersforum.com/forums/...se-143219.html

I still prefer boats with shaft drives for serious cruising.

[KeithB]

The SD50s on our Lagoon 420 had 2400hrs on clock when we purchased and are now approaching 4000hrs. We have replaced oil seals and change oil as often as possible.
No cone clutch issues - are we sitting on a ticking timebomb?

[kcj]

Originally Posted by KeithB

The SD50s on our Lagoon 420 had 2400hrs on clock when we purchased and are now approaching 4000hrs. We have replaced oil seals and change oil as often as possible.
No cone clutch issues - are we sitting on a ticking timebomb?

I was in a similar position—2003 lagoon 470. No issues thru 4400 hours. And I never identified any slippage until total loss of thrust— motored onto snorkel site fine, no thrust leaving...


But I had the 27mm socket, breaker bar and extension on board. As well as a Dremel with cutting wheels and lapping paste. And I’d gather the instructions on how to do it.

Some never have an issue, others seem to have it often. Your call. I opted to leave sleeping dogs lie. And lived to tell about it ... kow.

Cheers

[MartinR]

This summer I bought a boat with an SD50 with about 1800 hours on it. I was a little worried about it. So far no problem. The saildrive shifts very smoothly and is perfectly reliable. I have the upgrade kit onboard, though, and will install it this winter.

Oil changes can be made in the water, only need to buy two cheap hose fittings for this.

I think running hours are completely uninteresting for the clutches, it is more the amount of shifting you do (and how you do i)t that wears them down. Also, catamarans manoeuvre more using there (twin) engines, which will probably result in fewer hours between service.

Cone clutches are not very tolerant to abuse, so shifting distinctly and giving the propeller the time to stop in neutral and to engage in the new gear before throttling up will lengthen their life considerably.

The only problem I am seeing with the sail drive is oil level fluctuations - the upgrade kit with external venting will hopefully take care of it.

[Tornadosailing]

Can someone elaborate on the need for a Dremel and cutting wheel? What exactly needs to be cut?