Forums » Ask a Question

Use this forum to post your questions to our experts – you need to be logged on to do it (you can register here ), then scroll down to the bottom of this page and click the blue Post Thread words

If you can help answer the question, feel free to post a reply – you need to be logged on to do it (you can register here ), then hit the reply button on the thread.

 

To go back to the experts page click here>>

AuthorMessage
Trevormary
Trevormary

Posted: Sat Jun 15, 2013 8:47pm

Post Subject: Noisy prop

Dear sir,our narrow boat has a Lister LPW4 with a prm150 gearbox, we've just developed a noise which starts after about an hours running.When in neutral with the engine ticking over, if I turn the prop half a turn by hand the noise disappears,a further half a turn and it comes back,and so on. Any ideas will be appreciated.Thanks.

Tony-B
Tony-B

Posted: Sun Jun 16, 2013 8:58am

Post Subject: Noisy prop

"A noise" - what sort of noise? Check the engine mounts are tight. That is the bolts that hold them to the bed plus the big nuts holding the engine. Check that any flexible coupling you have is not braking up and is secure. Check the shaft is not bent and also try slightly tightening the stern gland - it could be the shaft banging about in the gland assembly and hitting metal rather than packing (assuming it is a conventional gland) - you do use the greaser enthusiastically don't you. make sure the gearbox has the correct amount and type of oil in it. Tony Brooks PS - if you find out what it is please let us know.

Woodycorne
Woodycorne

Posted: Mon Jun 17, 2013 5:27pm

Post Subject: Noisy prop

Mine is a slightly different situation but similar problem. I have a Barrus Shire engine with a PRM 150 gearbox. I have just returned from a couple of weeks cruising during which time the boat developed a deep resonating vibration mainly while in gear at low revs but also occasionally at tick over. Checking for loose deck boards and loose engine mounts did not resolve the problem.After reading your reply this morning I popped over to the marina and tried giving the stern gland greaser an 'enthusiastic' turn and the noise almost ceased. I tightened the stern gland slightly and hey presto, problem solved. Thanks for the tip, I don't think I would have thought of that!

Tony-B
Tony-B

Posted: Mon Jun 17, 2013 5:41pm

Post Subject: Noisy prop

Many thanks for that feedback. I based my reply on theory rather than any practical experience so its good to know it worked for you. The thing that is common to both situations is the low speed. At higher speeds I would assume it was a singing prop but that normally only happens at higher speeds. For information I usually give my greaser between 5 and 110 turns at the end of each day. That is until it goes stiff, plus one turn. That is the only way I know of ensuring the shaft is well supplied with grease. I have a suspicion that both boats may use one of those hard plastic R&D "flexible" couplings, except I do not think they give sufficient compliance for radial movement. Tony Brooks

Tony-B
Tony-B

Posted: Mon Jun 17, 2013 5:43pm

Post Subject: Noisy prop

PS that 110 should read 10. TB

Trevormary
Trevormary

Posted: Wed Jun 19, 2013 4:15pm

Post Subject: Noisy prop

Hi Tony, thanks for your reply,I checked the engine mounting bolts and every other nut and bolt I could see,no improvement! I next (while the engine was ticking over) disconnected the propshaft and the noise disappeared,(turned the engine off) then turned the gear box,nice and smooth,likewise the prop. On removing the plastic coupling I saw that the key in the brass prop flange was sticking out,it had been touching the plastic coupling.I loosened the bolts, knocked the key back in,connected the prop back to the engine,then ran it in gear for an hour,no noise!!. Have travelled for four hours today,still no noise. Thanks again

Tony-B
Tony-B

Posted: Wed Jun 19, 2013 4:49pm

Post Subject: Noisy prop

Thanks, pleased you found it. Cheers TB

Most Read

Newsletter Sign Up

Canal Boat monthly newsletter
Sign up to receive our regular email newsletter

Our Privacy Policy

Like us on Facebook



Follow us on Twitter

Cache: Disabled for this object  Total Queries: 44.  Total Objects: 163.  Total Unserialized: 4. Total Runtime: 0.52 seconds.