Twin Disc – black rubber pieces in the engine room?

[David B]

ENGINES = MAKE / MODEL – CUMMINS 6CTA8.3-M3, 450 HP – Age 2/23/00 (17.5 years)

TRANSMISSION – 506A 1.75:1 TWIN DISC #P8413

I am noticing small black 1/8″ size pieces of black soft plastic. It almost looks like off a belt. It is coming from the vents on my Twin Disc transmissions. A few pieces on the stb. engine (find 3 – 5 pieces) and port more ( find 5 – 10) after each run of the engines. I wash and clean the engine room after each trip and engine room is painted bright white.

Is this something I need to address asap? What is the course of action – pull the boat, shafts or can repairs be made in the water? I have PSS shaft seals.

Thanks!

Topic

[brian.brandler]

New to HB

Who did the repair for you? I had one side done right after I bought the boat, but the starboard side was supposedly on back order. I since then moved my boat from San Diego to HB and looking for a good mechanic to complete this starboard side for me. Any suggestions?

 

thanks in advance

[Tony Athens]

Torsional Coupling replacement Costs

Without knowing the exact gear model & engine, access to do the job, your capabilities, local labor costs per hour, etc etc etc, that would be an impossible question to answer……….

Most types of torsional coupling cost in the in the $400-$1000 Range . for mid-range sized engine & gears—-Then, you have the labor which can be the big one.

1 user thanked author for this post.

Greg Weaver

[Greg Weaver]

So I to have noticed these rubber pieces around my port engine, I also have a bit of rattle when i put it in gear briefly

If this is the torsional coupling going bad, whats is a rough guess on the repair for this if you have an idea

Thank you

Greg

[Tony Athens]

You have a MG5061A, not a MG506A..

Most likely your torsional coupling is like the one in the picture.. This particular design does this all to often……… Once it starts “falling apart”, things progress quite rapidly……Only solution is to replace it of have it rebuilt (Centa has a “program”for this–under $300.. They will not sell you any of the parts…

Depending on access, usually a good mechanic can do it in the boat by just removing the gear.

Tony

[Corey Schmidt]

Torsional coupling

I would be willing to bet that what you’re seeing are bits and pieces of rubber from your torsional coupling that is bolted to the engine flywheel and coupled to your gear… if this is the case, then at some point, you’ll need to pull the gear and replace the bad pucks and/or coupling entirely depending on the style of coupling you have…

[Philip]

It’s worth pulling the fan cover and inspecting the belt. Pull it off and give it a good visual. Also worth spinning everything and making sure it’s all smooth and quiet. Anything suspect change.

Most likely the peices are from the torsional coupling, so you will end up having to pull the transmission back at least 6 inches and change out the torsional coupling. Depending on access can take some time and creativity.

Any rattling at idle in gear?

[Author]

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