Mercury old style tnt cylinder disassembly 1977

ruddy mudder

Seaman Apprentice
Joined
Oct 1, 2009
Messages
45
Trying to remove the bolt on the inner ram plate inside the sleeve of the cylinder so I can slide off the end cap to replace the rod seal. It is very tight and am wondering if it is a left hand thread. Anyone got some info on this? Would appreciate some help from you vintage outboard guys out there, thanks! - Ron
 

merc850

Commander
Joined
Jul 7, 2010
Messages
2,046
Is it the 2 ram external type? If so here's the manual page:
trimcylrepair.jpg work in a clean dirt free environment!
 

ruddy mudder

Seaman Apprentice
Joined
Oct 1, 2009
Messages
45
Thanks LT, but the bolt will not turn out of the rod, I can't break with a 1/2" drive. Any ideas? Don't want to strip, snap or break anything (my knuckles). This is an 85 hp with the 1" rod.
 
Last edited:

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,950
That is the bolt that holds the piston to the rod? Item "i" in the drawing? It is not left handed. I also never found it to be very tight, either.
 

ruddy mudder

Seaman Apprentice
Joined
Oct 1, 2009
Messages
45
Yes, it is the bolt that holds the piston to the rod. Impact gun won't budge it, even at WOT. Somebody had to of rebuilt this thing and put a generous coat of thread locker on it? Unless it got stripped going back in. Only thing left that I can see would be to put heat to the top of the piston and hope it will expand enough to make clearance to loosen and use the impact again. Any other ideas?
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
Are you sure that O-ring "p" needs replaced? It isn't a wear item and is locked in place with bolt "i" unlike the rest which rub and wear on the liner and retainer.
 

ruddy mudder

Seaman Apprentice
Joined
Oct 1, 2009
Messages
45
Fluid is leaking out the end cap so I want to replace all the O rings while I'm in there. I just pulled the other cylinder apart and was able to remove the bolt with a 1/2" drive and a hammer on the rachet. Low and behold, there was red thread locker on the bolt and threads. This can't be factory could it? I can only imagine that the other bolt had the red stuff spread all over it like mustard on a carnival hot dog! Any suggestions how to loosen up this stuff so I can turn this bolt out? Thanks for all the input from all of you, I'm not a Mercury guy so this is all new to me, the engine came with the boat and runs too nice to remove and replace it with something else.
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
I would leave it alone. With no movement and the thread locker, the chances of the o-ring going bad is remote. If you keep trying to break the bolt loose you're risking breaking the bolt head off, breaking the rod or the eyelet.
 

ruddy mudder

Seaman Apprentice
Joined
Oct 1, 2009
Messages
45
Got the bolt out, used a heat gun to soften the thread locker and put the air impact on it. Problem solved! Thank you all for your input, especially Merc 850 for the diagram!
 
Top