Gearbox losing ‘oil’ (ATF)

[skip50]

Had a replacement Beta30 with TMC60A gearbox fitted over the winter. Very pleased with everything except for one problem.

The gearbox is losing ‘oil’ (actually Automatic Transmission Fluid). It is blowing out of the breather on the top of the gearbox. Not in massive quantities, but it shouldn’t be happening at all!

My engineer has looked at it and is at a loss. He has spoken to Beta and the gearbox agent, and they say they have never heard of this before.

Has anybody come across a similar problem? Any solutions, other than a replacement gearbox?

TIA

 

[doug748]

Has it been overfilled? Is it actually losing enough to be showing on the dipstick? If not I would get the level down to a mid point and see what happens.
It is often very difficult to read the oil level. Best to take the thing right out, into good light and then look for the tell tale red on the nicks in the rod; the lower one should have a red smear the upper should be clean.. Holding it against dry newspaper can also help to judge what is going on.

Are you sure it is the breather? Again it can be very difficult to judge. If the dipstick is not tight and pushed fully home it will leak in a lot use, as will the filler if the washer is missing or it is loose. Outsiders would be the rear oil seal and the drain plug but I guess you have eliminated those.

 

[Boater Sam]

If the oil level is higher than it should be it will leak out, I have seen this before.

The dip stick is not the best fitting item, it has to be properly pushed in with a seal on it.

 

[Refueler]

The TMC has an optional cooling system fed from engine system ... do you have such ?

Reason I ask is that my gearbox ... OK - I accept it is not same .... the cooling system developed a leak and it caused oil loss .... mine being raw system - the oil went out the exhaust - but if it had been a closed system - then it would have pressurised ...

Just thinking ..

 

[skip50]

The TMC has an optional cooling system fed from engine system ... do you have such ?

Reason I ask is that my gearbox ... OK - I accept it is not same .... the cooling system developed a leak and it caused oil loss .... mine being raw system - the oil went out the exhaust - but if it had been a closed system - then it would have pressurised ...

Just thinking ..

Thanks for the thought, but I do not have the gearbox cooling system you mention.

 

[skip50]

Has it been overfilled? Is it actually losing enough to be showing on the dipstick? If not I would get the level down to a mid point and see what happens.
It is often very difficult to read the oil level. Best to take the thing right out, into good light and then look for the tell tale red on the nicks in the rod; the lower one should have a red smear the upper should be clean.. Holding it against dry newspaper can also help to judge what is going on.

Are you sure it is the breather? Again it can be very difficult to judge. If the dipstick is not tight and pushed fully home it will leak in a lot use, as will the filler if the washer is missing or it is loose. Outsiders would be the rear oil seal and the drain plug but I guess you have eliminated those.

My engineer saw it coming out of the breather when we ran it in gear, I didn’t see it myself. Might check it next time I am on board. Never knowingly overfilled, and yes, I know about the difficulty in reading the dipstick, I use kitchen paper! Yes, you can tell the level is dropping on the dipstick.

 

[alahol2]

You can make the dip stick more readable. Heat it to cherry red and dip it into some engine oil. You end up with a matt black surface that shows the ATF much more clearly.

 

[QBhoy]

Hi. Is the engineer aware of warm and cold levels ? Just a thought. Quite often the reading on the dip stick is advised to be read in either/or condition. Fairly common for such a thing to end up with too much oil, if this is not considered.

 

[ChromeDome]

No personal experience, unfortunately, but have you checked the breather itself? There is a valve inside it, wonder if that could be the culprit..

The ATF volume is only 0,6 liter, so not a big problem to drain it for a closer look (fluid and plug should be clean) and refill with new.

In a similar situation (auto tranny) I fitted a piece of clear plastic tube over the breather to get a clearer picture of what was going on.

 

[skip50]

Just for future reference for anyone else with the same problem.

To recap, the ATF was getting aerated and coming out of the breather. This is on a TMC60A, with the 7degree down angle. To cut a long story short, a new gearbox seems to have sorted the problem, albeit only two hours running but I did a sea trail yesterday running at all revs, tick over to full revs and all is looking good.

This despite everybody saying they had never had such a thing before!

This may help somebody.

 

[Plum]

Just for future reference for anyone else with the same problem.

To recap, the ATF was getting aerated and coming out of the breather. This is on a TMC60A, with the 7degree down angle. To cut a long story short, a new gearbox seems to have sorted the problem, albeit only two hours running but I did a sea trail yesterday running at all revs, tick over to full revs and all is looking good.

This despite everybody saying they had never had such a thing before!

This may help somebody.

Glad to hear you now have a usable gearbox and can use your boat again.

www.solocoastalsailing.co.uk

 

[skip50]

Glad to hear you now have a usable gearbox and can use your boat again.

www.solocoastalsailing.co.uk

Thanks

 

[Spirit (of Glenans)]

My engineer saw it coming out of the breather when we ran it in gear, I didn’t see it myself. Might check it next time I am on board. Never knowingly overfilled, and yes, I know about the difficulty in reading the dipstick, I use kitchen paper! Yes, you can tell the level is dropping on the dipstick.

Blue paper towel is the best telltale for fluids, as it shows up dark when dampened.