1998 OX66 250 Gear Case Leak

[jwbergeron]

Had some water in the gear case, I was hoping it was bad gasket at the fill or vent plug. Vacuum and pressure tested it and turned the prop and drive shafts during both. Vacuum tested to 15psi, it dropped to 9 psi almost immediately, and held steady for quite awhile. Pressure test couldn't get above 10psi as it blew past the prop seal (I could hear it), but then that stabilized at about 4 psi.

Any thoughts on what I've got or suggestions on addl tests would be greatly appreciated.

Also, I noticed a grease fitting underneath the prop. I couldn't push any grease into it. Is this a point that should be greased regularly? I'm guessing mine hasn't been in 12 years!

Thanks fellas.

 

[robert graham]

Re: 1998 OX66 250 Gear Case Leak

Sounds like a bad prop shaft seal. Remove grease fitting, clean out old, hard grease with a piece of wire, clean fitting in solvent, replace, fill it with grease gun. Good Luck!

 

[rodbolt]

Re: 1998 OX66 250 Gear Case Leak

trust me, replace all the seals.
DO NOT buy a lower seal kit.
just buy all the seals and orings individually.
takes about 2.5 to 3 hours to reseal a standard rotation 3.1L gearcase.

 

[jwbergeron]

Re: 1998 OX66 250 Gear Case Leak

Sadly...this is the counter-rotating motor. Can the prop seals be replaced without pulling the bearing carrier?

How much pressure on the pressure & vacuum tests should be used? I can't seem find a consistent answer.

Many thanks!

 

[rodbolt]

Re: 1998 OX66 250 Gear Case Leak

no reccomendation from yamaha on vacum testing.
the spec for pressure testing your unit is about 14 PSI.
left hand case sucks big time.
its way out of what you can do at home.
takes me about 4 hours on a good day to reseal that left hand case.
also takes some special tools and a press or its simply not gonna happen
that grease fitting is simply to aide in bearing carrier removal if ever required, but thats why I have oxy/actyleyne.
what area of the world is this gearcase in?

 

[jwbergeron]

Re: 1998 OX66 250 Gear Case Leak

Old Saybrook, CT.

I'm about to go check the starboard motor...gear oil in this one was a bit milky too, but not as bad

Thanks Rodbolt.

 

[rodbolt]

Re: 1998 OX66 250 Gear Case Leak

if you wish to have it repaired, please use the yamaha dealer locator function, find a dealer that employs a master tech and make sure that tech does the work.

most likly the drive shaft seals are bad as well.

 

[jwbergeron]

Re: 1998 OX66 250 Gear Case Leak

Rodbolt, I'm friggin retarded! I just submergerd the port gear case and found out that the leak I heard was coming from the gage on the pressure testor. The prop seal on this one is fine. There is a big leak at the water pump, which looks pretty straight forward to replace.

On the standard gear case, the prop seal is leaking at about 10psi, as well as the seal around the shift rod. So, can I handle this prop seal at home? Should I replace anything else (i.e. orings) at the prop? Any special tools?

Thanks for your help.

 

[rodbolt]

Re: 1998 OX66 250 Gear Case Leak

on the standard case,you will need 2 carrier orings,2 propshaft seals,two drive shaft seals the drive shaft carrier oring the shifter cover oring and the shift shaft seal.
all easy.
the best puller to use is a harmonic balancer puller and the OMC v4/v6 puller legs.
on the left habd case, replace the drive shaft seals and the driveshaft carrier oring.
go play.
do a forum search on water pump replacement on the 1995 and up v4 v6 lower units for the water pump assy.

 

[jwbergeron]

Re: 1998 OX66 250 Gear Case Leak

Rodbolt, I can't get the bearing carrier out of the standard case. I made a puller with a piece of 1/2" plate and 2 threaded rods. Plate bears against the prop shaft, threaded rod in the bolt holes in the carrier body. I've tried heat between carrier and gearcase housing (inside and out, as the gearcase was sandblasted). I'm able to get a lot of force on the puller, but inevitably the rods break. Its soaking in PB now, Any thoughts? Am I doing something wrong?

Many thanks.

 

[rodbolt]

Re: 1998 OX66 250 Gear Case Leak

NO
the bolt holes are NOT for pulling.
go buy the puller legs from BRP or the slide hammer adapter from yamaha.
if you use the slide hammer you have to remove the shift shaft BEFORE trying to pull it.
then fire up the oxy/acetelyne, propane simply aint hot enough in the salt pond.
only thing PB will do is stink and make your eyes water when you reheat it.

 

[jwbergeron]

Re: 1998 OX66 250 Gear Case Leak

Thanks Rodbolt. The oxy/acetylene did the trick...it popped right out once I got it hot enough.

It was pretty straightforward after that.

 

[rodbolt]

Re: 1998 OX66 250 Gear Case Leak

I am almost 6 ft tall now,with my mag lite and my buck 110 and my DR sholls frankenstien shoes, I wiegh about 149.
I am a special scarecrow, I aint afraid of fire.
just wish I could spell.
last year I was at 141 so its all good .
graduated high school more years ago than I care to remember at 6ft2.
gravity and artheritis kinda sux.