Replace KM2A

[jackmace]

Well... I couldn't separate the ailing trany from my 2gm... so I pulled them both for a little trip & now Mack Boring has pronounced the transmission kaput! The price on a new km2a from a cold storage cave under the factory is way out there.
Looking about, it would seem that KM2c, KM2p, KBW10 have all been on various 2gm***. I even note a striking resemblence on the TuffTorq.com page under marine for the TTMC2P-1.
(TuffTorq, like Kanzaki, is a Yanmar holding Co.)

I have to call back soon and be sure that I am not forced to order a km2a special from the orient... Any & all input on trany swaps appreciated. It is almost worth rebedding for a 'new to me' upgrade for what they want on a special order *exact* replacement... I would think that a new prop (for a slight change in ratios) would be much easier with a bolt-up-sister transmission would be the easier route to take!

Of course, any suggestions for locating parts welcomed! I am in the Hudson Valley / New York area. Thanks in advance! -Jack

[Boracay]

As your transmission is kaput and your engine is very old (28yrs?) have you considered a total repower?

It may work out much cheaper in the long run.

[Alan Wheeler]

Jack, what exactly is wrong with the trany. Anything can be rebuilt as long as parts are available. Is the finding of parts the issue?

[Tropic Cat]

I guess it depends on what kind of failure it has. When they 'slip' in gear, it could be caused by glazing of the internal cone. There's a guy who wrote a short internet how-to on tearing the tranny down, resurfacing the cone (basically roughing it up with sand paper) and reassembling the unit. It worked fine.

[stickybeak]

Rick, do you have a link to the tranny tear-down site?

I've had the same problem with my 2gm20- with a frozen shaft so I have to pull the whole engine out to fix it. That'll be a first for me. I agree that at a certain point repowering sounds very attractive.

b

[never monday]

KM2's are reasonable to rebuild. Get it back with a detailed diagnosis.

[Tropic Cat]

Originally Posted by stickybeak

Rick, do you have a link to the tranny tear-down site?

It's here Catalac Engine Bits

Scroll down the page as it's the 2nd article. Although he doesn't specifically name the tranny. It's bolted to a 1GM and it's the same as the 2GM's tranny according to Yanmar.

[never monday]

1&2 Gm used the same variant of the KM2. The bell housing is shaped different. Internals look the same.

[Inlet Marine Services]

We are installing a 2YM15 today because of the age of the motor. Yanmar are great motors but they dont last forever.

[jackmace]

All Good & valid...

I have said many times that I wish I was a Checkbook Sailor. BOAT and all that. I'm a Nurse Married to a Teacher... with 1 in College & 1 in the wings. I can barely keep a slip. Have you *priced* engines???

This engine *is* my repower... I pulled an old YSM-12 out... thing would knock out your fillings! It is still awaiting adoption up at Marine Consignment of Wickford... This was from a 'light useage' wreck. I now wonder if the Trans took water...

I changed the engine bed to take the 2gm family... made sure that I can reposition for the 2gm 20... so that in 10 or 15 yrs I could get another Good ol' Engine for my Good ol' boat! This engine is a nice fit for my old Cherubini Hunter. It starts & runs like a demon... something I didn't have with the YSM 1-lunger... so I think the engine is worth holding on to. I would just like to have forward as well as reverse. I'm fickle that way.

I tried all the in place de-glazing tricks you will find on the net without success. In my service manual the process is outlined for completely breaking down the trans... and that is what you have to do to get to the cone for replacement. I couldn't get past the first lines... 'Loosen the mounting flange bolts & remove the clutch assembly' !!!

Anything is rebuildable.... and Mack Boring is willing to do that... but they say that a new transmission is cheaper than to rebuild my trany. (That is a new KM2A 3 weeks from the Orient at $1383.66 plus new damper $230 and 2 hours labor $250 plus tax...) You can see why I am interested in alternatives!

I will be getting back to them shortly to see just what is out-of-whack so bad that she should be reduced to razorblades.... I'll share what I learn...

The search continues! -Jack

[K38bob]

Can a KM2P replace a KM2a on a 2gm?
thanks
bob