Reassembly 90hp gearbox seals with RED loctite

[Sparkinator]

I’m replacing all the seals in the lower unit and the manual states reassembling with red loctite 271. Red is permanent, right? I’m a little concerned about being able to get those screws out of that aluminum housing with red loctite.

I hate not following the service manual, but I’ve got a red flag going up on this one. Anybody here use use blue loctite instead? Anybody have any suggestions? Thanks.

This is a 2000 Mercury 90hp ELPTO.

 

[Texasmark]

I’m replacing all the seals in the lower unit and the manual states reassembling with red loctite 271. Red is permanent, right? I’m a little concerned about being able to get those screws out of that aluminum housing with red loctite.

I hate not following the service manual, but I’ve got a red flag going up on this one. Anybody here use use blue loctite instead? Anybody have any suggestions? Thanks.

This is a 2000 Mercury 90hp ELPTO.

I have said this before and will say it again. Red is NOT your friend. I spent 36 years in the aerospace industry where reworks and mistakes weren't allowed, and Red was never used. In my 50+ years of boating and doing all my own work including what you are doing and beyond, Red was never used, nor did I ever see it used by others in the repair business.

Blue was the thread locker of choice as it held the fastener as was required and when required, the fastener could be removed without heat, damage to the fastener, damage to the threads, nor damage to surrounding items not part of the fastening process....like rubber O rings and such that you may have just put in as a new part.

You made a wise decision. Use Blue. I too see it referenced in the SMs but for the life of me I can't understand why unless the tech writers that wrote the manuals didn't know any better....and that happens. Ive been a tech writer too.

 

[jbuote]

Use Blue. I too see it referenced in the SMs but for the life of me I can't understand why unless the tech writers that wrote the manuals didn't know any better....and that happens. Ive been a tech writer too.

Just to add a little, Service manuals are indeed the best reference, but are not immune to mistakes/typos/errors..
As an example, my SM for a 1971 Johnson 50hp said to adjust WOT Timing at 3,500 rpm in neutral or in gear.
Didn't believe the "In Neutral" part, and asked here about that..
Some couldn't believe the manual said that, but it was confirmed it said "In Neutral" in their copy of the manual too!
Was advised that is a misprint or error, and should never rev that high in Neutral. (Confirmed what I already believed.)

Point really is, while service manuals are best, if you doubt what it's saying, ask here like you did.
Those "Red Flags" are worth paying attention to. Even in a service manual..

For what it's worth..

 

[Sparkinator]

Thanks guys. I’m not a fan of the red on anything im gonna rebuild. Especially on an inherently weak housing like aluminum.

When disassembling it, I saw some kind of thread adhesive in there, but it wasn’t red or blue. They call for red loctite on all the fasteners and on the O.D. of all the seals as well. Couldn’t believe it when I read it.

Ill just use the blue.