Gear oil leaking from top of lower unit

Especially if you notice this oil when laying the motor on its side. If there was any water in the lower unit when it went into storage then the water and gear oil eventually separated.

Find out where the oil is coming from.

Gear oil leaking from top of lower unit. Gear oil leaking out of the water intakes can only be coming from the gear housing seal below the water pump base. Remove the drive from the boat split the drive. Remove the water pump and impeller then the base plate.

There youll see the seal carrier. Gear Oil coming out of weep hole in lower unit You all have to drop your lowers check the shift shaft seal. The seal has been the same since 1963 since 91 been pushed into a plastic bushing.

Replacement seals push back out usually. Replace the whole bushing shaft assembly. The oil is leaking between the machined surfaces where the lower unit mates up with the mid section.

And it is leaking from a hole at the under side of the anti-ventilation plate above the oil level plug. If pressure was that high it would blow a seal first. The prop shaft seal is only rated for low pressure.

It should test good up to 12psi. 99 times out of 100 its just exhaust oil or fuel leak migrating to the plug recess. No water and its def leaking from the screwI used the boat a few times before i check the lower unit oil at that time it.

First of all the Honda 75 and 90s use Mercury 4 14 lower units. Honda buys them from Mercury so if necessary any Mercury dealer can easily service those lower units. Since youve got gear oil leaking out of the WATER intakes youve got a problem that needs immediate attention.

An engine stand also works wonders for holding the drive. Spread the mounting fingers wider and use longer bolts to bolt the upper to the fingers. Oil leaking from the weep hole in the front of the case is most likely a worn shift shaft seal.

They are a common failed seal that I have seen. It is a drain hole to drain water out of the midsection no exhaust comes out of this hoseto keep from freezing you have a seal leaking on the top end a drive shaft or shift rod seal. It needs to be fixed before using or it will lock up the lower unit.

Probally around 20000 with new water pump kit while the lower unit is off. Drop the lower tilt it up like it would if it was still attached. Note where it leaks from.

Reseal and replace gear oil. Drive shaftshift rod seal. As your under warranty DO NOT remove the plug or the evidence of an issue is gone.

New oil is pumped in from the lowest drain plug top plug out till it trickles out the top. Once up to level the TOP plug is put back in the pump tool removed from the LU and the drain plug. My lower unit is leaking oil.

I thought it was from either the fill plug or drain plug but those screws are purty friggin tight. And there didnt seem to be any oil. The lower unit oil was milky so I changed it.

I suppose it could be leaking around the plugs as I havent been real good about changing the o rings when changing that oil and I didnt put in new o rings in this time either. Was heading out to work and noticed that there was a decent amount of oil or gear lube that has leaked from my lower unit in the driveway. Last nigh got down to 28 just enough for the water to freeze in the dogs water bowl.

At first I thought that the lower unit had cracked. But upon further inspection I noticed that there are two pre drilled holes that the fluid is coming from. If your lower unit seals are bad enough to let gearcase lube leak out you will very likely see A SIGNIFICANT AMOUNT of water in your lower unit lube when you drain and change it.

A few drops of water is normal due to condensation so dont go nuts here. Its a drain hole for the exh housing. Its just unburt oilgas mixture coming out.

That is a drain hole as stated. If it is a black gooey mess it is unburnt fueloilwater mix that is draining from the gearcase. If it looks like gear oil your ds seal or shift rod seal may be leaking.

Especially if you notice this oil when laying the motor on its side. Install drain plug TIGHT with a new gasket and let the fluid drip drain out of the top plug until it stops. This is the correct fill level for most lower units.

Install upper plug with a new gasket TIGHT use the right tool and never worry about it until your next service or prop shaft seal leak or things start clunking or grinding. IF it really is gear oil it can only leak via the prop shaft seals which it clearly isnt the drive shaft seals below the water pump the shift rod seal boot or the gasket on the top of the gearcase not sure about this last one though. Replace the water pump and 2.

Find out where the oil is coming from. After getting it off the oil seems to be coming from the exhaust so I cleaners it all out of the chamber flushed the lower unit replaced all seals and gaskets put it all back together and still doing it. It only happens after running the boat and leaks for about a day then is done.

Providing that the pressure test shows no leakage in the lower unit remove the gauge fill the lower unit with fresh oil and move on to the real cause of the black oil. I have removed the lower unit and during the process of replacing the impeller I laid the unit on its side gear oil started to leak out of the holes on either sided of the case these holes are about 332nd round and apear to be vent holes Question is how and through what passage would alow oil. Brown lower unit oil is a sign of rust and is usually found in a gear case that has been sitting for awhile.

For example in a boat that is put in storage and left for a season or a year or two. If there was any water in the lower unit when it went into storage then the water and gear oil eventually separated. Is it leaking from the reservoir or overflowing from the top.

The latter is likely from the drive overheating. Watch over clamping the tube as its just plastic you are squeezing.