Losing Prop on Volvo Penta MD2030 Saildrive

[Pieter]

Hello,

Believe it or not, yesterday was the third (!) time i lost the prop on my motor (Catamaran, FP 40 ft), this time the port side motor. Earlier i had to manouver the boat in a canal with a lot of current and had to reach a slip 90 degrees to the current, so that took some quick ahead and revers motor movements. I believe it is this handling that makes the prop come loose? But, i actualy find it hard to believe, i mean, i am checking regularly the props etc and so, a little manouvering and the props come off???
Anyway, will have to order new prop, washer, cone, screw etc.. (at Volvo this doesnt come cheap).. but i am thinking of changing this system: why could i not just lock the prop to the axis with two sturdy nuts instead of using a flimsy cone that apparently is not cut out to do the job..
Any (multihull) cruiser out there that can shed some light on this?
In advance, thanks a lot...
(It is not easy to manouvre a sailing Cat with only one motor... at the other hand, thanks god it is a cat, as i have at least a one motor with a prop...)

Best rgds
Pieter
SV Onda Boa

[hugosalt]

Not familiar with Volvo saildrive/prop...so don't know is applicable but when I installed expensive folding prop on my Yanmar saildrive was very happy to see "tab washer" provided with prop to keep installation from backing off shaft.
"tab washer"...washer with tab/ears that get folded over nut
and locks nut in.
If possible maybe can work as part of belt and suspenders set up.
Best, Hugo

[Ram]

I also had this happen about a 1000 miles after picking up the new yacht at the factory- after i lost the prop I jumped in and checked the other one and it was ready to come off also- So I fixed this by using lock tite and not had any trouble since 6 years strong

[Pieter]

Originally Posted by hugosalt

Not familiar with Volvo saildrive/prop...so don't know is applicable but when I installed expensive folding prop on my Yanmar saildrive was very happy to see "tab washer" provided with prop to keep installation from backing off shaft.
"tab washer"...washer with tab/ears that get folded over nut
and locks nut in.
If possible maybe can work as part of belt and suspenders set up.
Best, Hugo

Ok, thanks Hugo... I get what you mean... I wonder, could i install a new prop and just lock the whole on the shaft?.. What is the purpose of the cone that is originally used.. I mean when i wont use the cone (and just nuts) would that have impact on the performance of the prop??

Thanks again for yr comments.
Best rgds
Pieter
SV Onda Boa

[hugosalt]

Also...don't know if recommended or not but I also used
much to much "red Loctite" to keep things from backing off.

Still always fear of prop backing off when must give a burst of power in reverse!

[Pieter]

Originally Posted by Ram

I also had this happen about a 1000 miles after picking up the new yacht at the factory- after i lost the prop I jumped in and checked the other one and it was ready to come off also- So I fixed this by using lock tite and not had any trouble since 6 years strong

Hi Ram, yeah i immediately checked the other prop, and this one was ok... In fact everytime i take the props of for cleaning and tightening the anodes, i wind a silicone type tape on the screw, and so far (untill yesterday) this worked well....

Dont you find it hard to believe that Volvo Penta has this kind lame prop/cone thing on their saildrives?

Best rgds
Pieter
SV Onda Boa

[belizesailor]

I have MD2020's with sail drives in my boat. Mine has a threaded cone that screws over the prop shaft and an allen head bolt that runs through the cone and into the center of the prop shaft. This forms an effective locking mechanism that has never cause me any problems.

Does yours have the center "locking bolt"?

[Pieter]

Originally Posted by belizesailor

I have MD2020's with sail drives in my boat. Mine has a threaded cone that screws over the prop shaft and an allen head bolt that runs through the cone and into the center of the prop shaft. This forms an effective locking mechanism that has never cause me any problems.

Does yours have the center "locking bolt"?

Hi BelizeSailor,
Thanks for your info... Yes, mine is the exactly the same system... In fact, i even wrap a kind of silicon locking tape around the thread of the locking bolt... all of this to none avail... the whole thing came off anyways... I am thinking of eliminating the cone and just put two nuts and locking split pen or so through the prop shaft..... Does the cone have another function?
Thanks again..and best rgds
Pieter

[belizesailor]

Fortunately I've never had this problem, although I have seen posts by others who have. I have also noticed some boats in the charter fleet here in Belize with seizing wire run through the holes in the cone and wrapped around the base of a blade on the prob -- not a very good solution. Based on posts, and the boats on which I have seen the above jury-rig, this problem occurs on both Volvo and Yanmar saildrives.

The cone helps with the hydrodynamics of the prop (because it does form a nice smooth tapper) so I would suggest keeping that as part of the set-up. I found an interesting post where they machined a longer locking bolt and put a spacer and nylock nut on the end of it. Seems like a reasonable and clean alternative to me.

See First Choice Marine Technical Group.

I don't use any kind of lock-tite like solution or tape on mine. I just grease all parts with a good quality marine grease and re-assemble. Never had a problem in 10 years of running this configuration. I do check-it occasionally just to make sure it is all secure and have never found it loose.

[bobconnie]

I would never use teflon tape on threads for a prop ! to slippery, and lock tite would work but your asking for some trouble maybe when ya try to take it off someday ! possible to strip threads from use of locktite, if you really want it to stay put, drill through the whole thing and insert either a taperd pin or through bolt it with stainless bolt and nut ! finished for ever. just a thought from an old timer who likes things to stay put !! Bob and Connie

[Ex-Calif]

MD2030 is an engine model. What model is your saildrive?

I have the md2010 and 120s saildrive. My system does use two nuts and one is a cone nut although I have changed the original folding prop to a feathering maxprop. The maxprop is a split housing that when installed will not allow the nut to back off. The two shells are held on together with 8 bolts and cotter pins.

I forget what the original system looked like.

I agree with others that a mechanical locking of some kind is necessary. I would not even trust double nuts without a cotter key, safety wire or the mechanical shell of my maxprop blocking the nut from backing inside.

I also would not put any locktite or teflon tape on the threads. I grease the threads to avoid seizure, not to hold the nut on!

[Pieter]

Originally Posted by belizesailor

Fortunately I've never had this problem, although I have seen posts by others who have. I have also noticed some boats in the charter fleet here in Belize with seizing wire run through the holes in the cone and wrapped around the base of a blade on the prob -- not a very good solution. Based on posts, and the boats on which I have seen the above jury-rig, this problem occurs on both Volvo and Yanmar saildrives.

The cone helps with the hydrodynamics of the prop (because it does form a nice smooth tapper) so I would suggest keeping that as part of the set-up. I found an interesting post where they machined a longer locking bolt and put a spacer and nylock nut on the end of it. Seems like a reasonable and clean alternative to me.

See First Choice Marine Technical Group.

I don't use any kind of lock-tite like solution or tape on mine. I just grease all parts with a good quality marine grease and re-assemble. Never had a problem in 10 years of running this configuration. I do check-it occasionally just to make sure it is all secure and have never found it loose.

Hi BelizeSailor,

Thanks again for yr comments and the link (solution) you mentioned. I will look into that...
Best rgds
Pieter Kommerij
SV Onda Boa

[Pieter]

Originally Posted by bobconnie

I would never use teflon tape on threads for a prop ! to slippery, and lock tite would work but your asking for some trouble maybe when ya try to take it off someday ! possible to strip threads from use of locktite, if you really want it to stay put, drill through the whole thing and insert either a taperd pin or through bolt it with stainless bolt and nut ! finished for ever. just a thought from an old timer who likes things to stay put !! Bob and Connie

Hi Bob and Connie,
Thanks for yr comments. However yr suggestion, allthough simpel and sturdy, wont work on the way Volvo has things set up (due to the bolt/pin that goes right into the centre of the shaft... I am thinking of púrchasing shares of Volvo Penta, as i did spent a nice amount on ordering a new prop, cone, washer and screw...

But, hey that is what it is...

Best rgds
Pieter Kommerij
SV Onda Boa

[Pieter]

Originally Posted by Ex-Calif

MD2030 is an engine model. What model is your saildrive?

I have the md2010 and 120s saildrive. My system does use two nuts and one is a cone nut although I have changed the original folding prop to a feathering maxprop. The maxprop is a split housing that when installed will not allow the nut to back off. The two shells are held on together with 8 bolts and cotter pins.

I forget what the original system looked like.

I agree with others that a mechanical locking of some kind is necessary. I would not even trust double nuts without a cotter key, safety wire or the mechanical shell of my maxprop blocking the nut from backing inside.

I also would not put any locktite or teflon tape on the threads. I grease the threads to avoid seizure, not to hold the nut on!

Thank you for yr comments Ex Calif.. You are right abt the motor vs saildrive...
I continue to use the original two blade fixed prop. I will get with Volvo, because i feel they should have all the ins and outs on this subject.. If (and that is a big if... i learn something from our Volvo friends, i will certainly post it here).. All the best
Pieter Kommerij
SV Onda Boa

[Cotemar]

I received two reports of Volvo Penta folding props falling off the sail drives.
One prop on a Mahe 36 and the other on a Lipari 41.
Please make sure that you have a good stainless steel locking tab and that you make sure it’s folded tight up against the bolt when you install your folding props. Put Blue Loctite on all threads and bolts. These props have a three way safety lock on them. If the first one is not properly done over time the two other locks loosen up and fall off.