I have two new HP transom assemblies that I am installing on my boat (Formula 353). The rubber gasket needs some type of gasket to hold it in place. I am seeing that Mercury recommends perfect seal and that seems to cross reference to permatex "aviation form a gasket". Anyone have any worries about using this? Seems to be the exact same thing. Next I am wondering if you would put any sealer on the studs that go through the transom or the flat part of the transom assembly at all. No I will not use 5200 or even 4200 as I know I would never be able to remove the parts with out lots of damage. I am seeming to see that the bolts torque to 25 ftlbs?

Thanks
Jon

Studs are inside of the gasket, if the gasket doesn't leak the studs wont. Perfect seal, bellows adhesive or the aviation sealant.

I still seall the studs in case water runs down the transom from the inside if you are spraying motor down.


But but I think it was over kill.

Definitely overkill if the transom cut out wasn't sealed, 90% aren't

Ok thanks guys am I correct on the torque spec? The transom is very well sealed (now anyhow). All bolt holes have been sealed as well.

yes 25 ft/lbs

I have used bellows adhesive before, forget the torque spec but its pretty low... over crank it you will usually crack something

book #1 of service manual #39, page 2a-8 and i quote,

tighten the transom assembly fasteners using an x pattern torque sequence starting from the middle fasteners.
tighten in small increments and go around the pattern several times until the proper torque is achieved.

so facing the inner transom plate; from left to right and from the top down, the x pattern toque sequence is,
5----7
3----2
1----4
8----6

Thank you. I did not see that on my book last night but I would have probably done something like that anyhow. Now I will for sure do it to that pattern.

+ 1 for bellows adhesive. All Ive ever used.