Rebuilding a 1986 350 cid Mercruiser inboard

[batexp]

So what we are working with here is a 1986 5.7 Mercruiser, reverse rotation with a one piece rear main seal . Just got my block back from the machine shop and spent most of the weekend installing it. The machine shop provided me with the full rebuild gasket set, new lifters and pushrods.

So about 3:am I snapped out of a dead sleep with a horrific thought....The gasket kit was a standard automotive (standard rotation) kit. Which means the crank seals (rear main, and timing gear cover) are for standard rotation. I called the shop and they assured me that because the cranks contact area is smooth rather than knurled it would not cause leaking.

My question is has anyone out there run across this situation, and if so what was the outcome?

 

[Bondo]

Re: Rebuilding a 1986 350 cid Mercruiser inboard

Ayuh,... I donno for Sure,...
but,..
I believe there are swirl marks on the Seals, depending on rotation, rather than on the crank...
If So,...
You'll have an Unstoppable leak...

 

[Don S]

Re: Rebuilding a 1986 350 cid Mercruiser inboard

There are differences in the rear carrier(retainer) and the seal, when using parts from Mercruiser. The front seal doesn't change. Just the rear seal and retainer.

 

[batexp]

Re: Rebuilding a 1986 350 cid Mercruiser inboard

Since I cant type my true feelings right now (due to the "no foul language" policy here) you guys will just have to use your imagination. @#$%^&

So with what you guys have indicated (and since 7 out of the 10 block shops have said it will be a huge problem), I now have a proper seal in will call at the local Mercruiser parts dealer. Looks like I'll be jerking the transmission off for the rear seal and the harmonic balancer for the front one (yes there is a different seal for that one also).

Sure wish I'd of had that revelation the morning before I started installing the engine (or that the block shop had mentioned the issue when I picked it up).

 

[RicardoMarine]

Re: Rebuilding a 1986 350 cid Mercruiser inboard

Agree...... There will be a difference in rear seals in-that the tiny little sirations are aiming opposite.
Two schools of thought regarding front seals...... older ones for reverse rotation were directional years ago. Probably a non-issue today!

Long shot: could you finagle a bore scope into the area to check color? Seems to me that these were colored differently to denote intended direction.

Now, since the engine is installed, why not just run it and see what developes?
Either way, if a seal replacement is necessary, the transmisson comes out.... Yes/No?
Or, it's do it now to avoid doing it later (probably a wiser choice!).

Tough call...... your call!

 

[Bondo]

Re: Rebuilding a 1986 350 cid Mercruiser inboard

Sure wish I'd of had that revelation the morning before I started installing the engine (or that the block shop had mentioned the issue when I picked it up).

Ayuh,... I forgot to mention,.... Welcome Aboard to the forums here at iboats.com.....

 

[littlebookworm]

Re: Rebuilding a 1986 350 cid Mercruiser inboard

I hate to add to you problems; but, if I remember correctly, you can't pull the front seal without pulling the timing cover. You can't pull the timing cover without dropping the pan. Therefore, I hate to say, I'm fairly certain you're going to have to pull the engine to drop the pan, to pull the timing cover, to change the front seal. I do hope I'm wrong; but I don't think so. I'm sure Don or Bond-o or someone else will jump in to either back me up or remind me of where I went wrong. Sorry. Hy

 

[Alpheus]

Re: Rebuilding a 1986 350 cid Mercruiser inboard

That is correct about the front seal. You can get the timing chain cover off without dropping the pan, but you will never get it back on. But the rear seal is what is in question...