PRM 150 Gerabox

[steelaway]

Hi everybody

 

Having had my gearbox for 4 years and 2000 hours, I started to wonder what wears out in these hydraulic 'box's

Can any one point to a detailed description or drawings of how they work?

 

Whats a bloody GERABOX? - a Clown with a keyboard. Mods please change

 

Alex

Edited October 4, 2009 by steelaway

[Bob the welder]

Hi everybody

 

Having had my gearbox for 4 years and 2000 hours, I started to wonder what wears out in these hydraulic 'box's

Can any one point to a detailed description or drawings of how they work?

 

Alex

hi. they did have a web site .may still have .BOB

[RobinJ]

Having had my gearbox for 4 years and 2000 hours, I started to wonder what wears out in these hydraulic 'box's

Can any one point to a detailed description or drawings of how they work?

The 150 (delta) round type PRM gearboxes are the lower torque end of the hydralic type scale and are on the whole reliable and simple!

They do not like getting hot and detiriorate rapidly if they do, otherwise they will last between 6 - 10 years with regular oil changes without any problems.

They consist of three shafts (input, output and lay) and the drive is selected by means of clutch plates which lock up the drive from one shaft to the other (selecting froward, neutral and reverse). These plates are operated by hydralic pressure from the pump at the rear through the selector valve.

Taking them apart to repair is a messy and tricky job, but instructions and details are available as were parts (I obtained some recently from ASAP).

Generally they will work for years until either the drive starts to slip (worn plates) or the seals start to leak (overheating).

You should find details herePRM 150

[blackrose]

Regular oil changes (about every 250 hours) are very important. An idiot in my marina has wrecked his PRM150 because he didn't even do the first change for 500 hours! It. Gets hot very quickly now and he loses power.

Edited October 5, 2009 by blackrose

[alan_fincher]

Worth noting that they say......

 

Gearbox oil should routinely be changed annually or at intervals corresponding with engine oil changes, whichever occurs first.

 

Many people appear to do it far less frequently, which seems a false economy, given how little oil is used at each change.

 

also

 

It is recommended that all Newage gearboxes be run for 15minutes before the oil is drained and replaced.

 

Which is something I was not initially made aware of.

 

You are also supposed to run the gearbox, and recheck the level again following a change. This is because running it may result in refilling the external oil cooler, and hence lowering the level in the box. They say over-filling can cause problems, as well as under-filling.

Edited October 5, 2009 by alan_fincher

[nb Innisfree]

When I asked Newage about oil change intervals they said every engine oil change, when I pointed out we have a L/Petter Alpha with 100 hr changes they said that was ok but when I mentioned that some engines change at 500 hrs they said that also was ok. In the end they said once a year! (I have mentioned all this in a previous post) It's all very flexible, changing same as engine is just a very rough datum. Same with type of oil, any good quality mono or multigrade will do.

[blackrose]

When I asked Newage about oil change intervals they said every engine oil change, when I pointed out we have a L/Petter Alpha with 100 hr changes they said that was ok but when I mentioned that some engines change at 500 hrs they said that also was ok. In the end they said once a year! (I have mentioned all this in a previous post) It's all very flexible, changing same as engine is just a very rough datum. Same with type of oil, any good quality mono or multigrade will do.

I think the first 50 hour service from new is important though. At least it seems to have been a factor in my neighbour's wrecked gearbox.

 

Also to add that the dipstick on the 150 should be screwed right down to check the level.

Edited October 5, 2009 by blackrose

[alan_fincher]

When I asked Newage about oil change intervals they said every engine oil change, when I pointed out we have a L/Petter Alpha with 100 hr changes they said that was ok but when I mentioned that some engines change at 500 hrs they said that also was ok.

Yes, been there, had that conversation!

 

I think if my engine required 100 hour oil changes, I'd only do the gearbox alternate times. It seems unlikely the gearbox needs more frequest changes coupled to a Lister than it does (say) coupled to a Beta, doesn't it!

[Bobbybass]

Hmmmm.....

 

My engine and gearbox has done 6200 hours....

The Beta 43 manual I have shows engine services 250 hours/ one year and PRM150 gearbox oil change at 750 hours or two years ....

Which is what I have always stuck to...

No power loss and no blue smoke from engine.

 

Maybe the Halfords 15/40 mineral enhanced oil is particularly hard wearing ?

 

Bob

[Keeping Up]

Mine was running too warm because the oil cooler was in the wrong part of the water circuit and the seals kept starting to leak It is not uncommon for the small O-ring around the selector lever to start leaking, but it is quite easy to replace.

 

On the old Delta the splines on the input shaft tended to wear, but they are much bigger on the 150 so hopefully that shouldn't be a problem.

[RobinJ]

On the old Delta the splines on the input shaft tended to wear, but they are much bigger on the 150 so hopefully that shouldn't be a problem.

The input shafts should be the same (I get confused with the change in numbering, the small one may have been different). Does it have 10 or 17 teeth?

It may be the wrong drive plate, there are two very similar ones with slightly different sizes one is SAE standard the other DIN standard (only about 1mm difference), this can cause the teeth to get worn.

[steelaway]

The 150 (delta) round type PRM gearboxes are the lower torque end of the hydralic type scale and are on the whole reliable and simple!

They do not like getting hot and detiriorate rapidly if they do, otherwise they will last between 6 - 10 years with regular oil changes without any problems.

They consist of three shafts (input, output and lay) and the drive is selected by means of clutch plates which lock up the drive from one shaft to the other (selecting froward, neutral and reverse). These plates are operated by hydralic pressure from the pump at the rear through the selector valve.

Taking them apart to repair is a messy and tricky job, but instructions and details are available as were parts (I obtained some recently from ASAP).

Generally they will work for years until either the drive starts to slip (worn plates) or the seals start to leak (overheating).

You should find details herePRM 150

 

 

 

 

Thanks Guys

 

Everthing you need to know about a gerabox within 8 hours - what great forum.

 

One last question Robin - do the clutch plates fail totaly or will they 'slip abit' before that? And would you notice?

 

Alex

[RobinJ]

Everthing you need to know about a gerabox within 8 hours - what great forum.

 

One last question Robin - do the clutch plates fail totaly or will they 'slip abit' before that? And would you notice?

They consist of 'plates' which should wear evenly (reverse presumably lasts longer?). So you should find 'slippage' developing slowly, initially at high power (i.e. when the props clogged) and then getting gradually worse!

[Keeping Up]

The input shafts should be the same (I get confused with the change in numbering, the small one may have been different). Does it have 10 or 17 teeth?

It may be the wrong drive plate, there are two very similar ones with slightly different sizes one is SAE standard the other DIN standard (only about 1mm difference), this can cause the teeth to get worn.

I was given to understand that the shaft on the Delta was a smaller diameter than that on the 150, hence the smaller splines and hence the wear.

 

When my old Delta started spraying oil out of the rear seal, I was told the cheapest option was a new box because my old one needed a new input shaft as well as everything else, and the total cost of parts and labour was only a few poounds less than the cost of a new £150. Given that my Delta was always a problem, leaking oil from the strangest places (such as between the two halves of the casing) right from the start, I was quite happy to take that advice at face value.

 

The 150 that replaced it leaked oil from its input seal, its output seal, and its selector seal. They were all changed under warrantee, without question; apparently sometimes these seals get age-hardened when the gearbox is stored dry before being sold.

[Paul & Julia]

Good evening sailors

 

Would anybody be able to advise if they know of any time limit for running the Prm150 in reverse. I was in a position this evening (would be when it was more than a tad wet) of dragging a boat off the bank after his rudder failed on high power taking him up the bank and finishing up like a ice breaker.

 

I know what you are thinking "to late now" but if I have exceeded some limit then I can possibly carry out remedial inspections or whatever is required.

 

Thanks

 

Paul

[nicknorman]

Good evening sailors

Would anybody be able to advise if they know of any time limit for running the Prm150 in reverse. I was in a position this evening (would be when it was more than a tad wet) of dragging a boat off the bank after his rudder failed on high power taking him up the bank and finishing up like a ice breaker.

I know what you are thinking "to late now" but if I have exceeded some limit then I can possibly carry out remedial inspections or whatever is required.

Thanks

Paul

Pretty sure the PRM150 is happy running either way so no time limit or damage potential.

[RLWP]

Honestly? If it isn't making significantly more noise than it did before - it's probably OK

 

Forward and reverse are identical, except that there is an extra shaft involved for reverse. So, the only different parts that might be vulnerable are the extra gear and it's bearings. If you have somehow damaged either one, then it will be a lot noisier in reverse than before. And I mean a lot, not 'Oooh, do you think that's a tiny bit louder?'

 

Richard

[Paul & Julia]

Thanks Richard and Nick

 

I feel better now

 

Paul

[Ricco1]

I'm glad I read this thread. More than one person has told me not to bother changing the gearbox oil on my PRM 150. This is now my next job.

[nebulae]

As we did not change the left hand prop. when we changed from SR2 to Isuzu,we have run the P.R.M.150 "in reverse for" 2,500 hours.Acording to the instalation instructions,this is not a problem,experience seems to prove this correct.

[Richard T]

As the dipstick is awkward to use and difficult to read I simply did this transferring the markings from one to the other The enlarged top will not allow it to accidentally end up in the box!! Even RWLP likes this!! The spanner is a dedicated 18mm which saves grovelling in the tool box to find one that fits.

Edited July 24, 2015 by Richard T

[luggsy]

First oil change should be 25hrs

[Boat&Bikes]

As the dipstick is awkward to use and difficult to read I simply did this transferring the markings from one to the other The enlarged top will not allow it to accidentally end up in the box!!IMG_3601.JPG Even RWLP likes this!! The spanner is a dedicated 18mm which saves grovelling in the tool box to find one that fits.

Clever, making one tomorrow.

 

Ian.

[tosher]

Are there not any thrust bearings to worry about?

[RichardN]

As the dipstick is awkward to use and difficult to read I simply did this transferring the markings from one to the other The enlarged top will not allow it to accidentally end up in the box!!IMG_3601.JPG Even RWLP likes this!! The spanner is a dedicated 18mm which saves grovelling in the tool box to find one that fits.

Oh I like that idea. Checking the oil level is a nightmare, I only mange it by rolling the dip stick on a glove but since been told put a bit of chalk on the dip stick.

 

Our PRM 150 just went as we were coming into a lock, I think we are circa 3500 hours, engine only run when we are moving. Our engine had been given a good going over by Isuzu engine guru Neil Coventry last Autumn, there were a few things that needed sorting but the gear box was fine, he was very surprised to hear that it had gone. Replaced with a refurb very smoothly by RCR / Bronte Boats. Sounds like clutches had gone but also there was a sliver of metal caught somewhere but not had the full story.