Lower unit leak

[irishflies]

I own a 1998 150 carb merc outboard. Inspected boat today and found a puddle of lower unit oil on the ground. I pulled the prop. The fluid is leaking from the seal. Is it possible to replace the seal easily? Are there specialty tools needed? Please help.

 

[JUSTINTIME]

Re: Lower unit leak

u will need a slide hammer
get the factory manual and read it over

 

[irishflies]

Re: Lower unit leak

I own a 1998 150 carb merc outboard. Inspected boat today and found a puddle of lower unit oil on the ground. I pulled the prop. The fluid is leaking from the seal. Is it possible to replace the seal easily? Are there specialty tools needed? Please help.

 

[irishflies]

Re: Lower unit leak

Thanks for the help Justintime. Does anyone know the difficulty of this job? I had the lower unit rebuilt a year and a half ago. I don' want to damage it. Does anyone have any good advice?

 

[JUSTINTIME]

Re: Lower unit leak

very easy
i would pressure test the unit first with vacuum and psi before ripping it apart8)

 

[Smig]

Re: Lower unit leak

Are you sure it's the prop seal that is leaking?

The pressure test will point you in the right direction, but don't forget to check the shaft and water pump base seal also. If it is leaking from up there, the oil can drip down the exhaust tube and come out at the prop.

 

[irishflies]

Re: Lower unit leak

Thanks Smig. That's great advice.Just the info I needed. Since I had my unit rebuilt about 18 months ago,Do you think it is more likely to be the lower prop shaft seal? There was no fishing line found when I removed the prop? Will the pressure test identify if it is the upper or lower seal? Thanks.

 

[JUSTINTIME]

Re: Lower unit leak

pressure test and put it in water
if u see bubbles coming out that is the problem
u only have 5 seals for gear case
pressure for gear oil out
vacuum for water in

drive shaft
prop shaft
bearing carrier
shift shaft
fill/drain o-rings

 

[irishflies]

Re: Lower unit leak

Great advice Thanks again. Will post the results.

 

[irishflies]

Re: Lower unit leak

I got my lower unit back last week. The propshaft seal was damaged,causing the lower unit gear oil leak. My mechanic replaced all of the seals in the lower unit again. I Had them done about a year and a half ago. He also replaced The water pump impeller. No telling what caused the seal damage. There was no fishing line found on shaft. Thanks for the help. I decided to pay the price for piece of mind. $500. luckily I have a partner. $250 is not as painful. Does $500 seem fair for this work?

 

[JUSTINTIME]

Re: Lower unit leak


how many hrs of labor

 

[j_martin]

Re: Lower unit leak

Several things can kill a seal.
1. Mechanical injury, on install, fishline, etc.
2. Heat
3. Excessive pressure (overfilling the gear case)
4. Shaft not smooth
5. Excessive runout (side play) in the shaft.

Keep an eye on it. If it happens again, find out why.

 

[irishflies]

Re: Lower unit leak

3.5 hrs. at $95/hr.

 

[JUSTINTIME]

Re: Lower unit leak

seems right to me