DPH drive help needed

[jimmy_the_builder]

So the list of post-refit teething troubles continues to grow...

While ambling away from the islands this morning, the port drive suddenly developed a slight but noticeable rubbing noise. After about 30s it got markedly worse, so at that point I shut the engine down. I then bimbled at 4kts to the cap, where I am now anchored just off Port Gallice.

I've had a look at the drive, and in the diagram below, bolt 27 has worked its way loose and the head of the bolt is rubbing against the hub of the forward prop.

So my questions are:
1. What are the implications of this bolt coming undone - could water have got into the drive?
2. If that is a possibility, what's the way to figure out if this has happened - drain off some drive oil and see if it's milky?
3. If it is, then would an oil change be sufficient or would some other work relating to seals be required?

 

[Geoffs]

I had this once, but mine was so bad both bolts 27 and 28 were bent, and bearing carrier 21 was distorted. Water entered the oil, milky, so all seals bearing and carrier had to be replaced. Volvo accepted as a warranty claim so don't know cost, a lot I suspect.

Yours probably not as bad, but I had no noise or any other indication. I didn't notice anything until boat lifted out of water, I dry berth, and saw everything bent and distorted.

I'm no expert, but if oil clear, maybe ok. If milky the seals probably need replacing, 4 I think. Check bolts 27 and 28, if distorted, there maybe more damage. I hope helps a bit.

 

[Andyroonot]

Bolt 27 is just holding on the end cover, which is just a piece of plastic. Bolt(s) #28 are the ones that keep the bearing carrier in place, and the o-rings around this that keep the oil in & the water out. So you 'should' be ok in terms of not having emulsified oil. I would imagine you'd need to take the props off to tighten/replace that bolt though

 

[A_8]

You should be ok from a water in the oil perspective but I would not want that bolt loose on my drives so the props need to come off. I've taken mine off several times with the boat still in the water but one need a beach safe from waves and wind, stable tide I guess where you are and some way to secure the boat. Clear water helps obviously. Perhaps you could back up one against of those ramps people use to put their boat trolleys on.

 

[jimmy_the_builder]

Thanks for the replies; I'm not going to attempt to take the props off in the water (I've never removed the props before myself, although I do keep the tools on board to do so, just in case); I'm going to go round to the yard in Port Vauban in the morning and arrange a lift out for next week.

I don't think I'll be able to see if it's just bolt 27 or worse until I've got the props off. Fingers crossed.

The other question is obviously how come it is loose in the first place. Not done up enough at last service? Vibrated loose during road transport? Any other ideas on this? (Should I be taking the props off tye other drive to check the bolt on that side as well?)

 

[benjenbav]

Thanks for the replies; I'm not going to attempt to take the props off in the water (I've never removed the props before myself, although I do keep the tools on board to do so, just in case); I'm going to go round to the yard in Port Vauban in the morning and arrange a lift out for next week.

I don't think I'll be able to see if it's just bolt 27 or worse until I've got the props off. Fingers crossed.

The other question is obviously how come it is loose in the first place. Not done up enough at last service? Vibrated loose during road transport? Any other ideas on this? (Should I be taking the props off tye other drive to check the bolt on that side as well?)

You're having some rotten luck. I would definitely want to find out why that bolt had worked loose and to check the other side for piece of mind.

 

[volvopaul]

Hi Jimmy, what work did you have done? New seals in the bearing housing? I've never seen one come undone before , I'd say it wasn't tightened up fully before props went on, as said it only holds the cover on, it's the two further in that hold the main housing in. It's not metal more a composite material. Oil should be ok unless the prop has pulled the thread out the housing, in that case you will need a new housing and the bearing preload set up.

 

[jimmy_the_builder]

Hi Jimmy, what work did you have done? New seals in the bearing housing? I've never seen one come undone before , I'd say it wasn't tightened up fully before props went on, as said it only holds the cover on, it's the two further in that hold the main housing in. It's not metal more a composite material. Oil should be ok unless the prop has pulled the thread out the housing, in that case you will need a new housing and the bearing preload set up.

Evening Paul, thanks for chipping in.

I think I did have new seals in one of the drives but honestly I can't remember which one (my notes are at home so I will know the answer when I get back).

Is the bolt supposed to be torqued up, or threadlocked, or just properly tightened?

 

[volvopaul]

Properly tightened up on service unless thread is stripped it should not come undone.

 

[jimmy_the_builder]

Cheers Paul. As it happens my assistant has been rather unfortunately checking his email this evening, so he's just sent me the service notes - and apparently it was the stbd drive that had new seals. Port just had oil change and "propshaft inspection".

Would it be possible to swap the drives over ie could port be installed on stbd shield? (Sorry if this is a really stupid question).

 

[GrahamHR]

Cheers Paul. As it happens my assistant has been rather unfortunately checking his email this evening, so he's just sent me the service notes - and apparently it was the stbd drive that had new seals. Port just had oil change and "propshaft inspection".

Would it be possible to swap the drives over ie could port be installed on stbd shield? (Sorry if this is a really stupid question).

The drives will be identical, so the answer is yes.

 

[jimmy_the_builder]

The drives will be identical, so the answer is yes.

Aha thanks for this. We had to change a bunch of parts on the supposed-to-be stbd drive, so it'll be very easy to establish which drive is which when the boat is lifted.

 

[rafiki_]

Jimmy, sorry to hear of further frustrations. Have you resolved the engine power issue?

 

[jimmy_the_builder]

Jimmy, sorry to hear of further frustrations. Have you resolved the engine power issue?

No; was expecting to have a person with vodia tool on the boat this trip but that isn't now going to happen given this latest fault. Rain/pours, etc.

 

[rafiki_]

No; was expecting to have a person with vodia tool on the boat this trip but that isn't now going to happen given this latest fault. Rain/pours, etc.

Yes, poor run of fortune given your great efforts over the winter. However, as things go in threes, is that not the third issue? Platform strut, engine power, and dph bolt? Should be fine now?

 

[jimmy_the_builder]

Yes, poor run of fortune given your great efforts over the winter. However, as things go in threes, is that not the third issue? Platform strut, engine power, and dph bolt? Should be fine now?

I like your thinking. Third issue is the autopilot, but that's another story.

 

[aquatom]

If it was the side that was resealed or not makes no difference as the cover would have needed to be removed to access the oil drain plug if you had the oil changed. So they would have both been off.
Check the gaps between the props as a bushed prop can move forward and toutch these bolts which then bends them and loosens them.
Is this on the opposite side to the engine with the lack of power? As a slipping bush can cause one engine to rev higher than the other causing you to think the problem is with the engine that has lower revs.

 

[jimmy_the_builder]

If it was the side that was resealed or not makes no difference as the cover would have needed to be removed to access the oil drain plug if you had the oil changed. So they would have both been off.
Check the gaps between the props as a bushed prop can move forward and toutch these bolts which then bends them and loosens them.
Is this on the opposite side to the engine with the lack of power? As a slipping bush can cause one engine to rev higher than the other causing you to think the problem is with the engine that has lower revs.

Wow. Yes, this is the opposite side to the engine that was down on rpm. Yes, both drives had oil changed. And yes again, I had suspected a bushed prop because I had noticed that the gap between the props on the port drive had opened up to about 10mm (instead of the usual 1-2mm). Funnily enough I had mentioned all of this in detail to one of the two dealers who worked extensively on the boat, but they didn't make the link between bushed prop and opposite side power loss (or the risk to this bolt).

As a slight tangent, why would a prop that was previously working completely correctly start slipping after six months off the boat?

 

[rafiki_]

As a slight tangent, why would a prop that was previously working completely correctly start slipping after six months off the boat?

Bushes etc drying out?

 

[volvopaul]

All this work done and still faults , did you carry out a sea trial in the Solent after launch jimmy ?