transmission repair

[rbtpfe9]

Is it possible to pull transmission (Kanzaki KM2A - attached to Yanmar 2GM) in water or is it necessary to haul out to drop shaft, etc?

[p32]

Given enough room to work the shaft away from the transmission flange there is no reason you should not be able to remove the transmission in the water. On some boats there may be hull structure that prevents such movement, but even then it is not required to remove the shaft completely from the boat for this job and technically anything you could do on the hard, short of removing the shaft, can be accomplished with a diver in the water.

I've twice in the last 28 years removed the transmission from a Yanmar 3qm30 while in the water. Never had any issues. I just loosened the retaining nut on the stuffing box, disconnected the two flanges, moved the shaft back far enough for clearance and unbolted the transmission at the bell housing. I did have to lift the rear of the engine for access to the lower bolts. The transmission (for the 3qm30) is not unmanageably heavy but it was very awkward with the large bell housing and poor leverage angles available in the engine room(box). We were able to use a line from the boom to aid in the handling. Make sure the shaft is clean before you push it into the stuffing box and I also was careful to keep it fairly well aligned while it was unbolted from the engine. Obviously if your boat has a configuration where the shaft COULD come out (ours can't, it's in an aperture) you would want to take precautions to prevent such an occurrence. In most cases I would imagine the shaft coupling would remain on the shaft and losing the shaft would be next to impossible.

After removal, we had it rebuilt and reversed the process to install. Don't forget to realign the shaft/engine even if you did not have to lift it as I did to get to the transmission bolts. I also replaced the packing in the stuffing box upon reinstall. Also don't assume the rebuilder has filled the trans with oil, check it yourself even if he says he did.

While the trans was out I did some cleanup and maint on the engine. There was MUCH better access with the trans and bell housing out of the way.
Good luck.

[rbtpfe9]

Is there an alignment tool? I've got one for a Merc stern drive but would doubt it would work here - any recommendations?

Thanks for relaying your experiences.

[p32]

Alignment tools simply consist of a feeler gauge that allows measurements to 1000's of an inch and the appropriately sized wrenches for the nuts on the engine mounts, oh yeah, and lots of patience.

If you've not had much experience working on a marine engines (I'm guessing from your question) in confined spaces both the trans removal/reinstall and re-alignment process may be pretty big jobs for a beginning DIY'er. Both also would be much easier with two people.

I'm sure you could find a number of books that describe the processes in detail. I'd start with the service manual for your engine. A Yanmar deal should have that. In FL, I happen to live near Mastry (http://www.mastry.com/) so that is where I got my manual.

Brian

[rbtpfe9]

I got the tranny out the other night, was not all that difficult - shaft slid back into stuffing box remarkably easy. I tightened everything back up to prevent water leakage. Our regional Yanmar rep is Mack Boring and have had no luck as of yet in obtaining schematic of tranny which has been promised now over several days. Unfortunately, the closest location to me is a 4+hour drive, so I can't "just go" and get it. Mastry does not cover my area. I think I've located the problem with my existing unit but without a parts catalog I'm dead in the water, both literally and figuratively! We'll keep on trying though.

[p32]

I just called Mastry. They told me they have parts and service manuals in stock for the 2gm engine and the Kanzaki KM2A trans. He did ask me if the engine was a 2gm or a 2gm-20. He also said the serial number would identify the engine as a European or US configured engine and that would ensure the manual matched the engine as close as possible.

He said the parts/service manuals for the engine were approx $30-$60 each. The trans service and parts manuals would be about half that-each. Seems like a lot of money for manuals but I can tell you after 28 years with my 3qm30, mine have been well used.

If you don't have any luck with Mack Boring, I could personally pick these items up from Mastry(I'd need the additional info noted above) and mail them to you.

Good luck
Brian

[rbtpfe9]

Thanks for the offer - specs finally arrived late this morning and hopefully parts are now on the way. I think Yanmar really does like their manuals but I do agree they are worth their weight in gold. Had to change out engine in my other boat last year due to hard freeze and cracked block but I saved over 4 grand from what my local Merc dealer was going to change it out for - made me think about changing lines of business but I don't think my knuckles and fingernails would last very long.

Thanks again for the suggestions - hopefully I can put everything back together again - I did get service manual although somewhat pricey.

[Faster]

As seen in the above exchange removing the gear with the boat in the water is certainly do-able - obviously saving the cost of a haulout on top of a likely costly repair.
HOWEVER - A word of warning for those with the increasingly popular dripless shaft seals. Attempting such a task then gets more complex.

These rely on the pressure on the seal from the shaft collar, and if the gear is removed there is no more seal. If you loosen the collar to move the shaft back, again you lose your seal.

It can be done if you can tape up the seal during the repair, but it's a dicy thing.

It's downright scary how much water can pour in there.

[bernard50]

Can you please direct me to a dealer with reasonable prices for Kanzaki KM2A parts.

Thanks,...Bernard

[Northeaster]

RBT - If you don't mi d me asking, what type of problems were you experiencing with your transmission? I had mine apart, and put it back together about a month ago. I lapped the inside of the drive gears with a bit of valve lapping compound, so that the drive cones made better (non slip) contact with them. I am not recommending this, I don't have much experience with it. Some members have voice concerns with possible cone wear, in doing this. However a member on Yamar.com swears by it, if your trannie is slipping out of gear. Obviously, there would be a point where the parts are worn too much, and this doesn't help. I will be trying mine in a couple of weeks, so we will see!!