Lost forward gear just now

Hey Ken,

Why would you have two reverse gears in the same boat? With neither engine being a contra-rotating engine, shouldn't one be a CR2 and the other a standard 72C?

Out of curiosity, I called my mechanic and asked about the price tag for the rebuild. He told me that it is what the shop charged, and that it is pretty typical for what he has seen recently. He said they have all come back $1900 - $2500.

When I asked him if the 72C would be cheaper than the 72C-CR2 he said that he didn't think so, at least by much, but that he didn't really know for sure because the last 72s he sent their way were all CR2s.

He did confirm that the control valve was rebuilt. He also reiterated that in my case it was a full rebuilding including the valve, all clutches and bearings, all seals, etc, and that it was now like new.

He said that his rebuilder might be more expensive than some because he does a lot of post-rebuild testing with a real motor and jig post-rebuild. And that he uses him because they come back on time and perfect 100% of the time and, he just doesn't want to mess with anything else.

So, from what I gather, the actual rebuilder was probably not the least expensive out there, but has served this mechanic well and the price wasn't the most compelling factor in his selection.

And, as I mentioned in other posts, after working with or interviewing half a dozen or so folks who were reportedly mechanics (but often lacked any discernible understanding of how motors work), I feel like I've won the lottery with this guy. He seems to go beyond basic understanding to having genuine intuition from experience, gets things done, gets them done right, his labor bills seem accurate, he answers my calls, and gets things done in a timely way.

...so, I'm not too worried about what his rebuilder charges, either. I was thrilled to get to enjoy the boat over labor day!

gkesden said:

Why would you have two reverse gears in the same boat? With neither engine being a contra-rotating engine, shouldn't one be a CR2 and the other a standard 72C?

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The CR2 can be set up to output same as engine or opposite, so you'd use one CR2 set up each way for counter rotating outputs. The ratio options are slightly different than the standard 72C and the output is lower than the input on the CR2 rather than in line, so you wouldn't want to use a 72C on one side and a CR2 on the other.

The CR2's come both ways. Reverse and non reverse. I have one of each which is normal. They have a "dropped" output shaft - on the order of 1.6" lower than the input. So while you certainly could use a CR2 for the reverse and something else for the non-reverse, they would have the engines in a different location, height and/or angle. So one has the reverse idler gear in it and the other doesn't.


Funny so much talk about the control valve, they are very simple.


Ken

CR2 manual.

Hey ken,

Thanks so much!

Somehow I totally missed that. I'd assumed the other one was a 72C. But, I am apparently totally wrong about that. I need to take a look at how it next time I am at the boat!

I guess I was looking more at the rebuild parts than the gear configuration when i was looking at the manuals and totally missed the difference in shaft configuration. I just somehow assumed that the "R" in CR2 was reverse.

My two gears do look alike to a casual observer, so I'm betting they are both CR2s. (Neither still has a plate).


My other gear is running well, reasonable smoothly and quietly, etc. Like I said, I think the reason the starboard one died was that chronic leak and low fluid situation. But, I am thinking of having it rebuilt in the early spring (after my winter break), just to have them both done. Right now the boat has 2 rebuilt engines and a reasonably new genset -- but only one rebuilt transmission. 20 years from now no one will expect only one to have been done. I was hoping to catch a break on the cost of the next rebuild -- but I guess not!

Another option is just, well, not to rebuild a perfectly good transmission. But, somehow, the asymmetry is bothering me. Maybe if I get the $4k in small bills and stack it on top of the perfectly good port transmission, it'll seem more symmetric and I can won't feel the need to spend it on rebuilding?

Thanks again!

-Greg

I had a transmission cooler fail last year. But instead of just losing all the ATF, the damn thing filled up with seawater. My understanding is if the cooler fails, ATF and raw sea water will mix, just as it did on mine.

My amateur suggestion would be to fill the tranny first and test it out in gear. Watch your wet exhaust on the water. If there's a sheen then the ATF is indeed leaking out.

Of course, as many suggest changing coolers every few years it certainly won't hurt to do just that! Good luck.

I would go ahead and change out the coolers unless you know how old they are. If the age is unknown then swap them out just in case, they are not that expensive compared to a transmission. I just painted the 2 new coolers I bought since I have no idea how old the ones in my boat are. Unfortunately the new coolers look beautiful and when I put them on the engines they will make the engines look bad...

What is the problem reaching the transmission ??

Greetings,
Have you lost your propeller?

What he said. That is way, way out of alignment. If it were my boat, I would run it only as far to a yard to have it aligned or not run till I did it myself. The standard is .001 per inch of flange diameter. So, if you have a six inch flange, best alignment is no more than .006 all around. Bad alignment stresses the entire drive train.

kchace said:

So are you saying that from top to bottom you have between .002 and .003 between the two flanges but the sides have a difference of almost 1mm? 1mm is almost .040" which is a lot to be out of alignment. That much could easily cause issues including noises and vibration.


Ken

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UPDATE - I got the new coolers, installed the one for the trans today, topped up the ATF, and started her up. Forward gear engages, reverse engages. Did not do a sea trial today, but hope to tomorrow.


When removing the old cooler, one of the female fittings on the side popped completely off when I went to loosen the hose! Damn, did not take much at all to pop it off. These coolers were top of list for replacement, but I figured I could at least get the old girl to her new home before I HAD to do them.


Many huge thanks to you all for your advice! I just got my TF burgee a day or two ago and will be flying it proudly on the bow!!!

Hopefully you caught it before any major damage happened. Good luck.

It’s possible that with no ATF you were unable to build the pressure needed to shift into forward. I would have thought the same would be true for reverse but hopefully the problem is solved.

CTP said:

When removing the old cooler, one of the female fittings on the side popped completely off when I went to loosen the hose! Damn, did not take much at all to pop it off. These coolers were top of list for replacement,

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When I rebuilt mine due to leaking port cooler, I completely rebuilt the port CR2 to include all new bearings. They were severely pitted. The starboard CR2 just needed clutches, gaskets and seals. Bearings looked good. I replaced both oil pumps because they are inexpensive. Probably wasn't necessary.

I replaced all coolers, hoses, and both heat exchangers. I also installed new damper plates while transmissions were off. I purchased a bunch of spare zincs for the exchangers to add to my spare parts tote.

If you have a good mechanic and he subs out the transmission work, expect him to markup the cost 20%. It's the nature of business. I have no problem with supporting a good mechanic.

rslifkin said:

The CR2 can be set up to output same as engine or opposite, so you'd use one CR2 set up each way for counter rotating outputs. The ratio options are slightly different than the standard 72C and the output is lower than the input on the CR2 rather than in line, so you wouldn't want to use a 72C on one side and a CR2 on the other.

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Exactly what I have, with slightly different ratios P and S. IIRC, 1.9P (72C) 2.0S (CR2) or close. My boat came originally with an engine sync gizmo that counted revolutions on the shafts and fed that info to a gauge on the dash, so trying to match shaft revs could never match engine revs. I scratched my head over that logic for a few years, then when it failed, I never tried to fix it. Far better to match through harmonics.

No reason I know of to worry about small difference in gear ratios.

CTP said:

UPDATE - I got the new coolers, installed the one for the trans today, topped up the ATF, and started her up. Forward gear engages, reverse engages. Did not do a sea trial today, but hope to tomorrow.


When removing the old cooler, one of the female fittings on the side popped completely off when I went to loosen the hose! Damn, did not take much at all to pop it off. These coolers were top of list for replacement, but I figured I could at least get the old girl to her new home before I HAD to do them.


Many huge thanks to you all for your advice! I just got my TF burgee a day or two ago and will be flying it proudly on the bow!!!

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would you mind sharing the name of your mechanic? It would be nice to have a contact of a trustworthy mechanic like that.Im glad you got her home. best of luck with your new boat.
Rob
Benicia, CA.

Thx.