volvo duo prop problem.. help please

[mikemcgregor]

I noticed some excessive vibration from port engine when throttling up from tickover. Vibrations increased as revs built up to around 2800. Then seemed to dissappear when up on the plane and pulling 3500. The boat was new back in the water after I had the props off and had them cleaned and antifouled. The engineer I use had the props removed and checked and he said one of the blades on the smaller prop was slightly bent and he had them sent away and reset. He then carried out a trial and has now told me the leg is still wobbling!! He suggests a new set of props!...Any ideas of best way to sort it? Thanks
PS. (Boat is in Spain and I am in the uk at the moment)

 

[Nat]

Hi Mike
If the vibration started before the prop was bent I would be looking elsewhere for the problem eg duff bearing or u/j, if after, then most likely the props. I have just brought mine back today for refurbishment at Steel developments as I did not think the spanish were up to balancing them...............Nat

 

[ians]

Mike
Agree with Nat. slighest dent or chip on prop will cause vibration, if its not the props I would look at the UJs which may be on the way out

Ians

 

[mikemcgregor]

Hi Nat... how is everything with you?
Vibrations started after boat back in water following liftout to antifoul. The engineer said one port prop blade was slightly out of line and was re set. he has not done a speed trial yet...only told me this morning that he "sensed" that the leg was wobbling when he motored slowly back to the mooring and that a new set of props would solve it!!!

 

[spannerman]

How did the smaller prop get its dent?, if you have had a propstrike it could be that the shaft is out of true, the longer shaft which drives the rearmost prop is the most vulnerable, could be worth having it checked.
If its OK then as Nat says it could be the U\J's, normally they will rumble on full lock when in neutral if they are on the way out, how long since the bellows were changed or inspected as you could have water in one causing the U\J to fail. Just checked my mates boat, the bellows were new last year he said so should be fine, lets take a look I said, and one had water in it, just a 1\2" in the bottom so we caught it in time before it rusted the U\J

 

[mikemcgregor]

legs were serviced in March. Dont know if/when propstrike happened as was only trolling around on last trip (before liftout) at slow speed and vibrations only happen once you get up to 2500 to 2800 revs. Dont notice vibs once pulling at 3800. Will invetstigate shaft alignment and u/j's. thanks

 

[Nat]

Hello Mike
Much better now ive finally got my props sorted after the gas bottle incident. just fitted one new set to worst (port) damaged side last week & everything seems ok. sent damaged ones to steel developments yesterday & they said they could do nothing with the larger of the 2 so I said sod it & bought a new one. Hoping to be back out on the 5th of July for Ibiza trip.
If you need any info on prices pm me.............Nat