Orientation of seals on lower unit

[Throttles Down]

I have a pair of 1999 150 OX66 EFIs that need the lower unit seals replaced.When cleaning the area to replace water pump noticed that the spring on the seal under the water pump was in pieces. The question I have is what direction is the seal under the outer seal? are the seals back to back or are both faces[side with spring] looking out away from the unit and are the prop shaft seals installed the same?
Thanks for you time
Don

[Sequoiha]

Well, this is a question that brings lots of responses and lots of arguments, the book says to have both springs down, toward the center, i have however been taught in school and other technicians and it is what i do, I place the seals back to back. and never had an issue, hope this helps.

[Aquasportfisher]

The parts microfiche shows both seals with the springs UP. I always thought this was backwards. Any other oil seal I've ever seen has the open end( spring side) of the seal toward the oil side of the application. That said, I have found it does not matter which way they ae installed as long as they are both facing the same way. I always pack the spring side with grease to keep the spring from rusting.

[Throttles Down]

Thanks
I was thinking back to back also, to keep pressure/oil in and water out
thanks again for your time
Don

[rodbolt17]

no factory Yamaha school EVER taught one in one out.
Both springs face out.
always has.
works well.
allows just enough seepage of oil out to lubricate the seal lips and shaft surface.
there is a reason.
instead of trying to reengineer something thats worked well simply fix it and enjoy.

[Mycarsucks]

I have a 1997 50HP

I had the lower seals replaced last year by a service tech. He explained to me that the seals failed because they were installed wrong. This was a surprise to me since the seals were never replaced.

Needless to say they failed again this year. My guess is that they were installed wrong.

My question is two fold.

1. Can I replace the seals myself with some basic tools? I am somewhat mechanically versed.
2. What is the proper way the seals should be installed on this lower unit? Factory pics would be appreciated.

[seahorse5]

I have a 1997 50HP


2. What is the proper way the seals should be installed on this lower unit? Factory pics would be appreciated.

Listen to Rodbolt and if you do not believe his previous post, then study a factory service manual. They both give you the correct answer that you seek.

[TownsendsFJR1300]

My Yamaha manual for my F150, as Rodbolt posted, does indeed show BOTH the prop shaft seals with the springs facing outward.

The purchase of a shop manual, IMHO, would save you a bit of aggravation and have the pictures to help.

[99yam40]

depth of the installation could make a difference also

[TownsendsFJR1300]

depth of the installation could make a difference also

+1 on the above.

I believe my F150 manual also showed (I believe), .2" in between seals as well. As stated earlier, a shop manual would save you a bunch of grief...