Volvo Penta SX-M Sterndrive Gasket?

[Space Goast]

I bought a new to me boat a month or two ago, as part of getting it ready, I pulled the stern drive and checked/greased everything. I followed a volvo workshop manual, and just applied grease where the stern drive separates from the transom shield assembly. I took the boat out a couple times, and I believe I have a gimbal bearing going bad (growling/vibration felt when trimmed all the way down or turning, seems worse when turning starboard). I remember spinning the bearing and u-joints by hand and they all felt nice and smooth.

I had a thought hit me that maybe I made a mistake on using grease instead of some sort of gasket or sealant where the case halves separate. Shouldn't this area be waterproofed/sealed? I can't find any reference to a gasket or applying sealant to this area in the manual, it just says to apply sealant to the studs themselves, not the face. When I removed the drive there was no sealant or gasket that I saw so I thought just greasing it was sufficient. Did I make a big mistake?

 

[cnotecherry]

No there is no gasket or sealant needed your bellows seals up to your pinion gear housing to seal up your u-joint however I do sometimes put some rtv gasket maker on the outer part of the bellows if I don't replace the bellows for peace of mind but it's not needed and there is an o ring type gasket to seal up the water pickup if you have taken off the leg again and there was no water in the bellows then you were sealed up

sometimes when you turn hard over one way or the other your power stearing will give you a hum or slight chatter I just don't go hard over if I can help it it is hard on everything

as far as being trimmed all the way down and having a vibration that's weird trimmed all down and steering straight is the least amount of stress on your gimbal and u-joints does it stop if you trim a bit up?

 

[Space Goast]

If I trim up a tiny bit then the feeling/noise goes away. From what I've read that points to a gimbal bearing...

I did have a big power steering leak at the steering rack, and am in the process of rebuilding that. Maybe the noise is related to the pump running dry. I found a couple other threads also saying no sealant is required, so good to know I didn't ruin the sterndrive by not sealing it. I'll do another water test after I get it back together and report on the trim down noise.

 

[cnotecherry]

Are you going to replace the gimbal? I would definitely do that anyway its relatively cheap and easy

 

[BRICH1260]

There is a rubber gasket that separates the water chamber from the exhaust chamber that fits in grove shaped like the gasket. You also need to add a liberal amount of grease on the nose of the drive where it enters the bellows and lube up the mating surfaces so they do not become seized together.

 

[Space Goast]

When I pulled the drive I put new orings on the driveshaft and the weird shaped one that I believe was for the water intake. I wire brushed both sides to get all the old gunk off and put grease all along the mounting area and the studs.

I am not 100% sure on the gimbal bearing yet. I put new fluid in the trim system and power steering, in two outings the power steering was empty and the trim fluid was milkshake from water intrusion. I have those apart and am replacing all the seals. I'm leaning towards getting the steering and trim cylinders rebuilt and listening again just to be sure it's still making the noise I believe is the gimbal bearing before I pull the sterndrive again.