Transmission Service Prop alignment

I have the Borg Warner 72c's and was getting ready to do an oil change. Reading through the Borg Warner Velvet drive Owners Manual it mentions a propeller shaft coupling shaft alignment and recommends it be done after a haul out.

It seems fairly straight forward with a feeler gauge, is it something you guys here do routinely after a haul out?

You will find more knowledge about dripless shaft seals and dripless packing than shaft alignment.

It’s not rocket science, but it can be tedious. Good alignment makes for leak free packing glands too. Well worth doing a time or two. Then you can pay someone like I do.

The boat can flex when hauled out so that the shaft alignment is thrown off. Probably worth measuring the gap once the boat is back in the water and has sat for a while. If you are not hauling the boat just loosen the shaft coupling, rotate, and measure the gap at 4 points around the coupling.

This is from the BW manual

It doesn't hurt to check alignment visually or with feeler gauge and shaft run out with a dial indicator. Any problems should be apparent. As previously mentioned, should be done with boat in the water.

I don't check mine on a routine basis. Marina hauls many boats each year including mine. Haven't heard of any problems. If I detect any unusual vibrations then alignment is on the checklist.

Propulsion motors that ride on soft mounts are actually impossible to align correctly, nonetheless, I always try to do the best possible job.
Alignment is necessarily done with the motor switched off, and no load on the propeller, however the moment it is put in gear, and torque loads are applied, everything changes.
Many boats run successfully for many years with very poor alignment, so maybe high precision alignment is just overrated!
My current ride has hard mounts, no rubber, and I feel confident that the alignment is spot on, even when high torque is applied.
The downside to hard mounts is irritating vibration at idle, so if I’m idling for any period of time, I’ll bump it up to 800, where it smooths out nicely.

SoWhat said:

...I don't check mine on a routine basis. Marina hauls many boats each year including mine. Haven't heard of any problems. If I detect any unusual vibrations then alignment is on the checklist.

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Same here so unless I see or feel a problem I don’t touch it. Hobo’s full displacement so the rpms are kept down.

Derik said:

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It seems fairly straight forward with a feeler gauge, is it something you guys here do routinely after a haul out?

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what are you planning to do with the feeler gauge, serious question? you are doing an oil change, you have no need to separate the shaft from the trans.

Wood boats are more likely to need an alignment check than fiberglass or metal. The smaller the boat, the more rigid the hull. I have found that an owner with the knowledge does a better alignment than the typical marina mechanic.

I check mine once a year, usually in the spring or anytime I hear an unusual noise or vibration. But I have a wood boat.

Lepke said:

Wood boats are more likely to need an alignment check than fiberglass or metal. The smaller the boat, the more rigid the hull. I have found that an owner with the knowledge does a better alignment than the typical marina mechanic.

I check mine once a year, usually in the spring or anytime I hear an unusual noise or vibration. But I have a wood boat.

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Bolded, why is that? This, not sure I understand.
And what would you do if yours is out of alignment. This, have you found it out of alignment.

http://www.tadiesels.com/assets/doc...ve_Marine_Transmission_Owners_Manual_0001.pdf

This link describes the alignment with a feeler gauge.

I changed the oil but didn't remove the cooler hose due to the fact the boats sat for a week and all the oil should have drained to the sump.

Soo-Valley said:

Bolded, why is that? This, not sure I understand.
And what would you do if yours is out of alignment. This, have you found it out of alignment.

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I'd expect than when a wood boat flexes on haulout, etc. it's more likely to un-flex back to a slightly different position. While fiberglass is more likely to un-flex back to right where it started.

When your boat gets hauled, make sure they block it correctly. One haul out the guys just put one block way forward and one way aft, had to align it in that condition because of some shaft work and it was way off once back in the water. I think ABYC says something like a minimum of 4 blocks and a maximum fo 6' between them. Also they should be putting wedges in tight as they let it down, not just to the nearest 2x6.

Derik said:

I have the Borg Warner 72c's and was getting ready to do an oil change. Reading through the Borg Warner Velvet drive Owners Manual it mentions a propeller shaft coupling shaft alignment and recommends it be done after a haul out.

It seems fairly straight forward with a feeler gauge, is it something you guys here do routinely after a haul out?

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Two part series on shaft alignment. It may be a smaller boat but the procedure is the same or very similar. It's not difficult but very tedious the first time or two it seems.

Lepke said:

Wood boats are more likely to need an alignment check than fiberglass or metal. ...............

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rslifkin said:

I'd expect than when a wood boat flexes on haulout, etc. it's more likely to un-flex back to a slightly different position. While fiberglass is more likely to un-flex back to right where it started.

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Googled this and cannot find any support to make general comments. If you have a reason to make such a statement based on some fact I truly would like to know.
I also could not find that any hull type flexes more or less than the other as a general rule. There are wood, metal and glass hulls made rigid or that flex due to poor design and cost cutting. These are usually copy cat boats of a popular style. In fact I was surprised to read an article on KK and Hatteras cored hulls needing to be re-cored due to poor layup, again not a generality.
I also read where some glass hulls flex noticeably on haul out, as in you can see the flex. I also read that a well designed and built boat of any material will ensure a rigid hull at least along the drivetrain to have no flex.

I also found it interesting that the owner manual had instruction for alignment but the service manual did not not. The original install manual has the same alignment instruction as owner manual, initial and once per year checks. I have flexible shaft couplings.

With further observation it appears I have the dreaded CR2 transmission not the 72c. They have 1650 and 1560 hours. they both operate fine but fluid on the port side was very dirty.

On that U tube shaft alignment...on bigger boats it should really be done in the water and probably should have 2 hose clamps on the packing hose if there is room and on a decent gland there will be.

Derik said:

With further observation it appears I have the dreaded CR2 transmission not the 72c. They have 1650 and 1560 hours. they both operate fine but fluid on the port side was very dirty.

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Nothing to dread about. CR2's are solid as a rock. Wouldn't run them in reverse all day at full throttle but otherwise they are simply overdesigned 71C's with a special reduction gear.

Keep the ATF changed, they will last forever. Dirty fluid probably indicates worn clutch plates but nothing to be concerned about.

Derik said:

With further observation it appears I have the dreaded CR2 transmission not the 72c. They have 1650 and 1560 hours. they both operate fine but fluid on the port side was very dirty.

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The issue with the CR2's is that some specific - and critical - parts are increasingly hard to find, which means that rebuilds may be anywhere from $1300 to several thousand depending upon what's wrong. So, with that in mind, they ought to be treated well and maintained carefully. Ensure clean fluid at the proper level (factor cooler capacity into that level). Change fluid regularly. Shift in and out of gear at idle speed only. Maintain proper shaft alignment. Investigate any odd noises or behavior promptly.

One of your gears will rotate opposite the engine, indicated by an "O" designation on the model/serial plate. Those gears have a reversing gear that is held in place with an interference fit. Forty years of motoring at a 10-14 degree down angle can coax those gears loose. When that happens, they walk into the large ring gear in the reduction housing and start chewing up the teeth. You don't want that to happen.

Anyway, more than you asked about, but it's good to know what you have and how best to keep it going for many more hours. Given the low hours on your gears, I suspect you have at least a couple thousand worry-free hours ahead of you.

David

PS - And if you've never checked your alignment, it might be a good idea.

CR2 Transmissions

I hope mine work for another 1500-2000 hours. I talked to American diesel today and he didn't seem to be a big fan and didn't think a rebuild when needed would be money well spent. The alternative seems much more expensive and if a rebuild means 4000 plus hours then I'll probably go that route. Hopefully I have plenty of time to ponder.