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SG Boater

Drive to Bell Housing Gasket

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Took the boat out for first time Sunday since doing an engine alignment.  When doing a lookover afterwards I noticed the Drive to Bell Housing Gasket was pooched out on both sides where the gasket and mating surface is only about 1/8" wide, ie. next to the big water supply o-ring on the port side, next to the shift lever on the starboard.  I drained the drive unit oil, it looks perfect with no sign of water contamination so nothing happened to the lower unit.  Gasket was pooched out enough that the entire orange bead is out on the starboard side so pretty sure some water made it's way in.  Tonight I'll pull the drive, inspect and hopefully put all back together with a new gasket.  My thinking is, since the drive unit oil checked out fine, potential issues would be water got past the big square o-ring and into the u-joint bellows, and into the shift cable.  Shift cable is stainless so will try to blow some compressed air through it from engine side, but even if can't the water should evaporate and no issues down the road.  If water got into the bellow, drain/dry everything and pump some fresh grease into the gimbal bearing.  Are there any potential issues I'm missing and is there anything else I should do to address?  2nd question, any suggestions how to keep this from happening again.  I've probably pulled alpha's off 15 or 20 times, never had this happen before.  This time I was thinking what a poor design this is with that 1/8" wide or so area that has to seal so I put a dab of bellows adhesive to hold the gasket in place.  I'm thinking that was the issue?

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On an Alpha, the big o-ring at the input shaft jam nut is there to keep the castle nut from turning, not to seal the bellows chamber. You should expect to see water in the bellows void, gimbel bearing, and both U-joints. Dry her out, grease her up, and hope for the best.  Depending on how high the water level got, your transom plate sump may also be full of water too, which means your coupler splines may have gotten wet as the gimbel bearing seal seldom is totally water-tite.  W

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Thx Wingnut.  No water was in the bilge that I saw so hopefully not much water made it in.  Open it all up and let air dry?  Am I right with my thoughts on the shift cable.  Finally, install the new gasket without any sealant or bellows adhesive?  I'm not familiar with the transom plate sump.  It isn't something I can access on a 210 with the engine in it.

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3 hours ago, SG Boater said:

Thx Wingnut.  No water was in the bilge that I saw so hopefully not much water made it in.  Open it all up and let air dry?  Am I right with my thoughts on the shift cable.  Finally, install the new gasket without any sealant or bellows adhesive?  I'm not familiar with the transom plate sump.  It isn't something I can access on a 210 with the engine in it.

If you lay on top of the engine AND LOOK STRAIGHT DOWN BEHIND THE BELL HOUSING, YOU WILL SEE THE DRIVE SHAFT EXIT THE ENGINE COUPLER. JUST BEHIND THAT IS A LOW SPOT IN THE TRANSOM PLATE THAT CAN COLLECT WATER. ALSO, WHEN YOU SET THE DRIVE GASKET, i ALWAYS SPRAY ON SOME ADHESIVE TO THE GASKET SURFACE SO IT STAYS EXACTLY WHERE i PUT IT. cAN'T SEAL IF IT'S DISPLACED AS YOU ALREADY KNOW. 

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Can't lay on top of engine, have a 210ssi.  But fortunately all the worry was for naught.  Just pulled the drive and 4 or 5 drops is all that came out.  Not even a single drop in the bellows.  Big sigh of relief, avoided a problem.  For some reason the orange bead split, some stayed in the seam, about 3/4 pooched out, both sides, port and starboard.  I had it where it was supposed to be when installed, not sure how or why moved.  So using a little bellows adhesive is ok?

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In 15 or 20 drive removals, only used adhesive the last 2 and this is the 1st time this happened.

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15 hours ago, SG Boater said:

Can't lay on top of engine, have a 210ssi.  But fortunately all the worry was for naught.  Just pulled the drive and 4 or 5 drops is all that came out.  Not even a single drop in the bellows.  Big sigh of relief, avoided a problem.  For some reason the orange bead split, some stayed in the seam, about 3/4 pooched out, both sides, port and starboard.  I had it where it was supposed to be when installed, not sure how or why moved.  So using a little bellows adhesive is ok?

As I said, I use 3M spray adhesive as I'm just trying to hold it in place, not seal it. Too thick of a bead of anything will cause it to hydraulic out of position when tightened. Less is more in this case, and torque to spec, and not beyond. W

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Any trick to keep the gasket from pooching out on the port side due to expansion of the water passage oring when the drive is drawn up tight?  I used 3m spray adhesive, just enough to hold in place during assembly.   It isn't strong enough bond to overcome pressure from the oring.  I can just see the edge of the orange bead for about 3/4 inch just outboard of the oring.

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PS, my assumption is that it's due to the oring expansion.  Gasket was in perfect position prior to drawing down the final bit.  And the pooch is right next to it.

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1 hour ago, SG Boater said:

Any trick to keep the gasket from pooching out on the port side due to expansion of the water passage oring when the drive is drawn up tight?  I used 3m spray adhesive, just enough to hold in place during assembly.   It isn't strong enough bond to overcome pressure from the oring.  I can just see the edge of the orange bead for about 3/4 inch just outboard of the oring.

Are you using an OEM Merc gasket set of an aftermarket?  Are you over-torquing the retaining nuts, or has it been done in the past so that the gimbel is distorted? Check surfaces with a straight edge, as I've never had this happen.  W

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Quicksilver gasket, 27-94996Q 2, new nuts torqued to 50 ft lbs, and checked with a straightedge before installing last night to ensure I didn't have a low spot that wasn't compressing and holding the seal in.  Surface was nice and flat as far as I could check by eye with a steel ruler (carpenters square).  Starboard side is perfect, but not port.  It had been a couple years but I didn't remember the water passage o-ring completely filling the recess like these do now, and they're thick.  There's a fair amount of rubber to displace somewhere.  the other thing I noticed is the drive appears to be about 1/16" narrower than bell when installed.  It all lines up on starboard side flush, but you can see the port side is in farther, ie. a lip if you move your hand from the back of the drive to the bell housing.  With this I'd expect if the seal was installed flush with the bell housing, you'd always see a little gasket on port, but it's visibly pooched a little so that as I said above, I can see a bit of the orange bead.

I've got extra gasket sets, I'll try again tonight.  Any thoughts would be appreciated. 

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1 hour ago, SG Boater said:

Quicksilver gasket, 27-94996Q 2, new nuts torqued to 50 ft lbs, and checked with a straightedge before installing last night to ensure I didn't have a low spot that wasn't compressing and holding the seal in.  Surface was nice and flat as far as I could check by eye with a steel ruler (carpenters square).  Starboard side is perfect, but not port.  It had been a couple years but I didn't remember the water passage o-ring completely filling the recess like these do now, and they're thick.  There's a fair amount of rubber to displace somewhere.  the other thing I noticed is the drive appears to be about 1/16" narrower than bell when installed.  It all lines up on starboard side flush, but you can see the port side is in farther, ie. a lip if you move your hand from the back of the drive to the bell housing.  With this I'd expect if the seal was installed flush with the bell housing, you'd always see a little gasket on port, but it's visibly pooched a little so that as I said above, I can see a bit of the orange bead.

I've got extra gasket sets, I'll try again tonight.  Any thoughts would be appreciated. 

This one really has me stumped.   W

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I just took some pics but too large to add.  They don't really show anything anyhow, just a sliver of orange next to the drive adjacent to that oring.  Isn't visibly pooched so much as by feel.  Can definitely feel it sticks out more at the oring.

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Redid tonight, made sure everything was perfectly aligned and gasket glued in place.  Even shaved off the gasket edge next to the oring.  Torqued to 25 foot lbs and everything still perfect.  Then 40 and started to pooch out.  At 50 foot lbs almost the entire orange bead is showing.  Going to get an oring tomorrow of slightly smaller circumference so it can displace in the bell housing recess rather than pushing the gasket.

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Had a Sierra gasket set on the boat as a spare.  Oring is 1/16" smaller OD.  Worked perfect.  Oring size is 1 5/16 x 1/8.  Mercruiser is 1 3/8.

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