Noisey PRM 150

[ROBDEN]

Asking this for a friend.

 

A noisey prm 150 gearbox. About 12 years old and 3000 hours.

 

Changed the drive-plate a while ago which made it quieter (it was really knackered)

but it’s still quite noisey.

I can only describe the noise as a fast ‘chattering’ sound. Don’t know the condition of the

gearbox drive/input(?) shaft.

 

Wondering about having the box reconditioned.

Any recomendations as to who would do this please or would it be better to get a new one?

 

Any help or advice will be much appreciated.

 

Rob….

[Tony Brooks]

Any chance a bit of drive plate debris has been left in the flywheel housing?

 

Chattering does not immediately make a gearbox fault come to mind but I am not saying it is not within the box, especially if it chatters across a wide rev band. But I hear there has been some instances of PRMs suffering gear chatter at certain speed if a drive plate with the wrong degree of stiffness has been fitted.

 

Again worn input shaft splines can chatter in the drive plate.

[ROBDEN]

Thanks Tony.

 

The flywheel housing was cleaned.

Maybe chattering was the wrong description. maybe 'rattling' is better.

 

 

 

Rob....

[bizzard]

It might be worth checking your starter motor, it might be loose or the pinion may be worn and floppy and become too close to the ring gear rattling teeth with it.

[Tony Brooks]

Chatter and rattle both indicate a degree of percussion where as I would expect noise from gearboxes to be mainly whines or whirs from rotating parts. I know some early (huge) PRMs had a problem with rivets in the multiplate clutches but I have never heard of that for years.

 

But was the cavity in the noise of the starter cleaned out? It would not be the first time a bit of broken drive plate was left there and later moved.

Edited September 13, 2015 by Tony Brooks

[Bee]

I think I would separate the box from the engine and have a look, if it is across a wide rev band it sounds like loose stuff, whilst you are there see if the splined shaft wobbles. Before you do that though just have a look at the couplings along the shaft, they were tightened properly weren't they??

[RLWP]

I suspect that that this is worn clutch plates. The splines on the inside wear

 

I think I have some pictures somewhere

 

Richard

 

MORE: Thought so: http://www.canalworld.net/forums/index.php?showtopic=62999

Edited September 13, 2015 by RLWP

[ROBDEN]

Thanks Richard.

 

If the the box is to be stripped to examine the clutch plates, then I think that they may as well be replaced along with any other bits that may be worn.

Do you know if these parts are readily available? Or should it just be handed over to the professionals? If so, any recommendations?

 

Rob….

[RLWP]

ASAP have them: http://www.asap-supplies.com/marine/prm-150-parts-for-layshaft-assembly/prm-clutch-repair-kit-prm-150

 

That's for one clutch, you may get away with that. Reverse is usually OK

 

You'll need the seal kit too: http://www.asap-supplies.com/marine/prm-150-parts-for-layshaft-assembly/prm-seal-gasket-and-o-ring-kit-prm-150

 

And the manual is on their website: http://www.asap-supplies.com/marine/spares-and-accessories-for-prm-150-gearboxes

 

Richard

 

MORE: Looks like the workshop manual isn't, so it's here instead: http://www.dintra.com/download/PRM%20150D%20Workshop%20manual.pdf

Edited September 13, 2015 by RLWP

[ROBDEN]

Thanks all, I'll pass all this info' on.

 

Rob....

[adrianh]

I have a low hours prm150 box for sale, what ratio is the faulty one?

[ROBDEN]

I have a low hours prm150 box for sale, what ratio is the faulty one?

Sorry I've been out.

I'll find out ratio tomorrow morning.

 

Rob....

[dor]

ASAP have them: http://www.asap-supplies.com/marine/prm-150-parts-for-layshaft-assembly/prm-clutch-repair-kit-prm-150

 

That's for one clutch, you may get away with that. Reverse is usually OK

 

You'll need the seal kit too: http://www.asap-supplies.com/marine/prm-150-parts-for-layshaft-assembly/prm-seal-gasket-and-o-ring-kit-prm-150

 

And the manual is on their website: http://www.asap-supplies.com/marine/spares-and-accessories-for-prm-150-gearboxes

 

Richard

 

MORE: Looks like the workshop manual isn't, so it's here instead: http://www.dintra.com/download/PRM%20150D%20Workshop%20manual.pdf

 

Useful links. Thanks.

[craftycarper]

Thanks all, I'll pass all this info' on.

 

Rob....

. I know it's not a fix, but as the owner of a 40 year old landrover, which have a lot of noise issues in the box and are the week link in the chain, it's not uncommon to slap a pot of slick50 oil treatment in the box, does wonders for quietening them down and makes them a bit smoother

[ROBDEN]

. I know it's not a fix, but as the owner of a 40 year old landrover, which have a lot of noise issues in the box and are the week link in the chain, it's not uncommon to slap a pot of slick50 oil treatment in the box, does wonders for quietening them down and makes them a bit smoother

Thanks. I was wondering about that myself. Or even a heavier oil.

I have a low hours prm150 box for sale, what ratio is the faulty one?

PM sent.

[Tony Brooks]

I think Slick50 contains PTFE and I can see no way that is going to help the wet multi-plate clutches in the box. Like wise Molyslip is likely to have a detrimental effect. In any case I do not see how worn splines can be corrected by an additive or thicker oil, but it might cushion the wear.

 

Please do not extrapolate from automotive practice and give advice unless you are well versed in marine technology. I know such advice is often ment well but can all too easily cause more problems.

[ROBDEN]

I think Slick50 contains PTFE and I can see no way that is going to help the wet multi-plate clutches in the box. Like wise Molyslip is likely to have a detrimental effect. In any case I do not see how worn splines can be corrected by an additive or thicker oil, but it might cushion the wear.

 

Please do not extrapolate from automotive practice and give advice unless you are well versed in marine technology. I know such advice is often ment well but can all too easily cause more problems.

Thanks Tony, sounds like good advice.

 

While you're there, in the workshop manual it says that excessive noise through the operating range could be due

to a defective input coupling.....Do they mean the drive plate?

 

Also another reason could be prop shaft misalignment. Is it worth detatching the prop shaft then running in gear to see or will

it need to have some pressure applied to the gearbox?

 

Your thoughts would be much appreciated.

 

Rob....

[RLWP]

.Do they mean the drive plate?

 

Yes

 

Richard

[ROBDEN]

Thanks again Richard.

[Tony Brooks]

Anything that you can do for free is worth a try so Yes, by all means try it with the coupling bolts out. However if it is chatter on the clutch splines with most of the load removed the oil film might be strong enough to cushion the chattering faces.

 

The chattering is caused by the engine speeding up and slowing down twice in every revolution and that is unavoidable with reciprocating engines.