Isuzu IM4LC38 Engine/PRM 150 Gearbox oils

[Ewan123]

Hi folks, it's time for an oil change and I'm hoping for some reassurance/advice please.

 

Engine: Isuzu IM4LC38

Gearbox: Newage PRM 150

 

The gearbox has Granville Hypalube Plus 15W/40 in it (because that's what the previous owner used). I'm not certain what exactly we have in the engine (the other empty bottle sat in the engine bay is Cooper TransFlow SD 15W-40, could be that or we may have disposed of the old oil with the bottle that came from the new oil - I don't recall. Bad me, lesson learned). 

 

As per the manuals the gearbox wants mineral API CD 15W/40 and the engine wants API CC 15W/40 (or CD if CC is not available, mineral/synthetic not mentioned).

 

1) The oils used so far appear to be... wrong? The Hypalube is CG and the Transflow is CI if I'm reading correctly.

2) That being the case, I want to replace with the Proper Stuff as specified. How thorough do I need to be in draining and flushing the old oils (and what's the best way to flush it out)?

3) Any recommendations for affordable (or otherwise) API CC and CD?

 

Thanks in advance.

[LadyG]

I have a PRM 150, the advice on fluid was changed after manufacture, ie after original manual. I phoned the company, they advised ATF Dextron 2 by Westway Lubricants.

I have an Isuzu LB33 and currently using oil from Morris, it's Classic. 15 40 for older marine diesels  £35 delivered pre war. There is more choice of oils. 

 I tried to get  API CC   it has to be non synthetic, which is for modern diesels. Others will advise. Did you try search?  It has been discussed before.

There is a magnetic sump plug under the gearbox, use long arms, I just drained it, I think it had never been changed, there was only 0.6 l of black oil in it, rep!aced with about 1l ATF as I recall.

I don't think you can economise on the oil or the fluid, Morris deliver, next day, I've never seen any suitable ATF in a chandlery, though a larger marina might stock suitable engine oil, about £30 pre war.

I change fluids after a good run in gear, make sure it's not too hot!

I change the ATF once a year whether it needs it or not, lol, and engine twice a year, I'm not doing long hours, 500 per annum I think.

I change fuel filter annually, and oil filter as engine. I use OEM filters, it costs £7 per annum more.

Others will be more knowledgeable,  I'm sure they will advise!

Tony Brooks has a website with lots of valuable training information

 

Edited May 1, 2022 by LadyG

[Tony Brooks]

40 minutes ago, LadyG said:

I have a PRM 150, the advice on fluid was changed after manufacture, ie after original manual. I phoned the company, they advised ATF Dextron 2 by Westway Lubricants.

I have an Isuzu LB33 and currently using oil from Morris, it's Classic. 15 40 for older marine diesels  £35 delivered pre war. There is more choice of oils. 

 I tried to get  API CC   it has to be non synthetic, which is for modern diesels. Others will advise. Did you try search?  It has been discussed before.

There is a magnetic sump plug under the gearbox, use long arms, I just drained it, I think it had never been changed, there was only 0.6 l of black oil in it, rep!aced with about 1l ATF as I recall.

I don't think you can economise on the oil or the fluid, Morris deliver, next day, I've never seen any suitable ATF in a chandlery, though a larger marina might stock suitable engine oil, about £30 pre war.

I change fluids after a good run in gear, make sure it's not too hot!

I change the ATF once a year whether it needs it or not, lol, and engine twice a year, I'm not doing long hours, 500 per annum I think

Others will be more knowledgeable,  I'm sure they will advise!

 

 

I think this is incorrect advice. The hydraulic PRM boxes use engine oil so your 15W40 is fine.  I think the 150 is hydraulic.

 

For the engine try to get mineral oil. You may have difficulty finding CD at a decent price so i would accept CE as long as the engine is well run in.

[LadyG]

35 minutes ago, Tony Brooks said:

 

I think this is incorrect advice. The hydraulic PRM boxes use engine oil so your 15W40 is fine.  I think the 150 is hydraulic.

 

For the engine try to get mineral oil. You may have difficulty finding CD at a decent price so i would accept CE as long as the engine is well run in.

OK, I was thrown by the hydraulic bit, my. PRM150 is presumably just a gearbox? I contacted Newage who made the gearbox, I understood they had problems.

UPDATE just realised I've got a prm120, sorry about giving wrong info!

Edited May 1, 2022 by LadyG

[Slim]

Just now, Tony Brooks said:

 

I think this is incorrect advice. The hydraulic PRM boxes use engine oil so your 15W40 is fine.  I think the 150 is hydraulic.

 

For the engine try to get mineral oil. You may have difficulty finding CD at a decent price so i would accept CE as long as the engine is well run in.

I can confirm that PRM Newage current recommendation is for 15w40 Mineral Oil.  I have just come off their website where the handbook is downloadable  .

1 minute ago, LadyG said:

OK, I was thrown by the hydraulic bit, my. PRM150 is presumably just a gearbox? 

PRM 150s are hydraulic. Your PRM150 gearbox is the same as all others !! (ratios excepted)

[Tracy D'arth]

A 15W40 oil, CD or CE or CG will be fine for both. They are not fussy. The old CC grade is now harder to find.

Not synthetic or semi synthetic, just plain multigrade oil.

 

*************Do NOT put Dextron or any other automatic gear box fluid in a PRM150, it takes engine oil only. The PRM mechanical boxes take auto fluid, the hydraulics all take engine oil.

[Tony Brooks]

1 minute ago, LadyG said:

OK, I was thrown by the hydraulic bit, my. PRM150 is presumably just a gearbox? 

 

I think that your 150 is a hydraulic gearbox. A large sort of oval think that has been mounted on the engine looking all lopsided. Luckily the duty in an automatic automotive box means it is good oil so you are unlikely to have done any damage.

 

Are you sure that yours is not a 120 mechanical box?

[LadyG]

28 minutes ago, Tracy D'arth said:

A 15W40 oil, CD or CE or CG will be fine for both. They are not fussy. The old CC grade is now harder to find.

Not synthetic or semi synthetic, just plain multigrade oil.

 

*************Do NOT put Dextron or any other automatic gear box fluid in a PRM150, it takes engine oil only. The PRM mechanical boxes take auto fluid, the hydraulics all take engine oil.

I got this advice direct from Newage, so I'm not sure why they would give the wrong advice, confused now.

Eeks, mine is a PRM120

 

Edited May 1, 2022 by LadyG

[Tony Brooks]

2 minutes ago, LadyG said:

I got this advice direct from Newage

 

Maybe, but were you clear which gearbox you have? I can't see PRM advising ATF for any of their hydraulic boxes. I think someone either gave bad information or got hold of the wrong end of the stick. Who, I have no idea.

Edited May 1, 2022 by Tony Brooks

[Ewan123]

Righto, mineral 15W/40, then CC, CD, CE or CG  in order of preference. It is well run in at 15 years old.

 

I did read on another thread that API CC is particularly recommended to help prevent glazing (over winter we are charging batteries with the engine but do cruise most weekends) - does that ring true?

[Tracy D'arth]

23 minutes ago, Ewan123 said:

Righto, mineral 15W/40, then CC, CD, CE or CG  in order of preference. It is well run in at 15 years old.

 

I did read on another thread that API CC is particularly recommended to help prevent glazing (over winter we are charging batteries with the engine but do cruise most weekends) - does that ring true?

A bit of ash in the oil seems to help avoid bore glazing. For this, many use recycled oils working on the theory that there may be a bit of debris still in the oil, unlikely I would think.

 

I buy the cheapest tractor 15W40 I can find, usually CG.

[Tony Brooks]

29 minutes ago, Ewan123 said:

I did read on another thread that API CC is particularly recommended to help prevent glazing (over winter we are charging batteries with the engine but do cruise most weekends) - does that ring true?

 

Well, sort of. If you always charge at idle then maybe, especially if the engine is not well run in. However if you charge at the speed that gives maximum  charging amps then the alternator load nowadays is probably larger than when cruising.  As the charge drops reduce the revs to stay at maximum amps. Try to find a river or rives section every year   where you can open it up and really load the engine for a good while.

[Alan de Enfield]

1 hour ago, LadyG said:

I got this advice direct from Newage, so I'm not sure why they would give the wrong advice, confused now.

Eeks, mine is a PRM120

 

 

That is why you should avoid giving advice when you do not know what you are talking about.

[Ewan123]

55 minutes ago, Tony Brooks said:

 

Well, sort of. If you always charge at idle then maybe, especially if the engine is not well run in. However if you charge at the speed that gives maximum  charging amps then the alternator load nowadays is probably larger than when cruising.  As the charge drops reduce the revs to stay at maximum amps. Try to find a river or rives section every year   where you can open it up and really load the engine for a good while.

 

Ah grand, should probably be alright then. We've got two 70A alternators and I do just that, only going down as far as idle when the amps into the leisure drop below about 25A (which is about what idle gives us).

 

We've only had short river stretches in the last year or so but we're aiming for Limehouse to Brentford in a few months so that should do the trick!

 

Thanks to you and all for the advice.

[Tony Brooks]

1 hour ago, LadyG said:

I got this advice direct from Newage, so I'm not sure why they would give the wrong advice, confused now.

Eeks, mine is a PRM120

 

 

So ATF is the correct gearbox oil for your gearbox.

 

At one time PRM only made hydraulic boxes, then they introduced the smaller mechanical boxes and kept the engine oil recommendation for them as well. it seems they had some clutch problems and changed the recommendation for the mechanical boxes to ATF. That seems to have caused a degree of confusion amongst boaters.

[Steve56]

This is what PRM publish.

[john.k]

Never use any engine oil that says "Friction Modified" in the spec in a wet clutch gearbox or transmission.........these modern engine oils will certainly make wet  clutches slip.