Gearbox oil

[JasB]

Just thought I had better check the gearbox oil before mounting my engine, Yuk! Cream coloured, rotton onion smell, droplets of water....might be time for a change. I undid the drain plug, and a black toothpaste textured goo emerges followed by the creamy onion soup. The question is how do I flush the rest of this muck out? I am considering petrol, but perhaps parrafin might me a more suitable medium? and once the flushing solutin is in, should it be aggitated to clear the old oil out? if so how?...to cut a long question short: how do I flush the gearbox?

 

[bdsweeting]

Having your tried engine flushing oil ?

 

[JasB]

How does One use it? and what is the cost

actually, I can probably check it out on the web

I did check it out, and the problem is most require the engine to be run, and this is not an option yet, perhaps just replace the oil until the engine is fitted and running and then flush?

 

[sailorman]

http://search.ebay.co.uk/oil-flush_W0QQfcclZ1QQfclZ4QQfnuZ1QQfsooZ1QQfsopZ1

 

[Norman_E]

From your post I presume that the engine is out of the boat. If so then you are lucky because that gives you the possibility of draining it completely, which is often impossible once installed. It looks as if your gearbox oil has been contaminated with water. You do not say what type it is, or what lubricant it uses. If it is the type with wet multiplate clutches, and uses automatic transmission fluid, then using anything else might leave residues that will promote clutch slip. In that case simply wash it out a couple of times with the correct lubricant. If it is a small and fairly light gearbox then separating it from the engine and putting the fluid in, and shaking it, might work, but if it is really bad I would bite the bullet and strip it down to clean it..
For a gearbox that uses ordinary oil, washing with paraffin, or diesel fuel, then a change of oil to get rid of the paraffin or diesel, might work.
You do need however to find out how the oil became contaminated. If the gearbox is cooled by the engine coolant, is there a leak? Unless you cure any leak, the problem will recur.

 

[JasB]

[ QUOTE ]
You do not say what type it is

[/ QUOTE ]
Engine is a Vire 7, but the gearbox:-

[ QUOTE ]
The reversing gear is coupled directly to the rear part of the engine. The propellor thrust is taken up within the gear; forward and reverse action being provided by two cone clutches on a splined shaft.

[/ QUOTE ]

...erm...you tell me! /forums/images/graemlins/shocked.gif

It takes SAE90 but has been stood for 2 or 3 years so the water (not a lot) is probably condensation

 

[VicS]

[ QUOTE ]
It takes SAE90

[/ QUOTE ] The rotten onion smell is normal for an EP gear oil.

I would let it drain thoroughly to begin with.

I would consider flushing with paraffin if I could be sure that most of it will drain out or maybe a flushing oil or even something like "gunk"

After draining throughly I would then fill with engine oil and give that a brief run of a few minutes under no load once the engine is back in commission then drain and refill with the correct oil.

 

[Norman_E]

Good advice from VicS. When I asked what type it was I was thinking of the distinction between wet multiplate clutch gearboxes which use Automatic transmission fluid, and cone clutch types which use engine oil, or gear oil, as in your case. The latter seem to be more forgiving regarding what you can put in them. If the amount of water was very small then a flush out with a lighter oil, followed by refilling with the correct thick stuff should sort it out.

 

[nordic_ranger]

If I remember correctly from my Vire 7 days water gets into the Gearbox because a seal ('o' ring) in the back of the water pump needs replacing.

 

[JasB]

Job for tomorrow sorted then...thanks all

 

[Csail]

Glad you reminded me.....my sterngland went a few months ago and the gearbox was onder water... would water have got into my oil?

 

[Birdseye]

Gearboxes arent designed to be immersion proof so the answer is probably yes. However, seems a bit pointless to ask us when we havent seen it / cant check it - the best answer is to check it yourself. /forums/images/graemlins/smile.gif Drain and re- fill.

 

[RobBrown]

Supplementary query to this thread, if I may.

I have a Bukh DV 20 with what I believe is a Hurth (HBW?) or ZF gearbox.(No manual). The nameplate model no is BW7, which on internet searches comes up as a probable old ZF model. I believe it takes ATF, but would be grateful if anyone could confirm? Even better if someone can point to a manual (tried ZF & Hurth websites, but no trace of this model in the download docs).

 

[Norman_E]

If the oil in it is quite thin, and red in colour it is probably ATF.
Unfortunately I am unfamiliar with those makes, so can only suggest that you take a sample of the oil in it and compare with ATF, which is pretty thin stuff. If your oil is thicker than car engine oil, then it is probably gear oil.

 

[Norman_E]

A bit of research has shown that the BW7 gearbox is an old ZF model, which was fitted to bukh engines among others. I suggest you ask a bukh dealer, who may remember what was used in them.

 

[RobBrown]

Norman

Thanks for your replies. I have found a handbock for an HBW 50 transmission system on that Dutch engine etc manuals site and that is specced for ATF & it looks quite similar to the box on my engine, so I strongly suspect it is ATF, but will take up your suggestion of contacting Bukh UK- I have done so in past re the engine & found them very helpful.