Aligning motor with a flexible Drive coupling

So I replace the motor mounts on my cat 3208 in the course of an oil pan replacement. So this week I am going to align the motor. I have a plastic Drive saver device between my transmission output flange and the prop shaft flange. With this setup what is the proper way to A-line the motor? Should the drive saver be removed?

I'm thinking the only way would be to align flange to flange and then re-install the drive saver but I've not seen one up close. I'm looking at changing the mounts when I replace a damper plate this winter. Which mounts did you use?

When they aligned our motor they removed the drive saver, aligned flange to flange & then reinstalled the saver.

Greetings,
Mr. 30. Mine were done in the fashion described by Mr. ADC. Flange to flange alignment then re-installation of the drive saver.

The 3208 is very smooth running motor, I would not spec a drive saver for such. If shaft length is appropriate I would be done with the drive saver and go coupling to coupling.

If you want to retain the drive saver, try to line it up coupling to coupling and then pull shaft back and install the saver. If there is a little misalignment, the saver can adapt to that.

There are also spacer flanges on the market that can go between the flanges for either alignment purposes or for permanent install.

Aft Deck Capt said:

I'm thinking the only way would be to align flange to flange and then re-install the drive saver but I've not seen one up close. I'm looking at changing the mounts when I replace a damper plate this winter. Which mounts did you use?

Click to expand...

I bought those mounts from go Marine over the Internet. Honestly I don't know what manufacturer they are I just looked at the weight and size. These are heavy engines so you have to make sure the mounts have enough capacity

I am looking at a 1984 Nordic Tug for purchase. A recent survey of the boat recommends aligning engine. What is the level of difficulty or cost. Access to the engine mounts seems pretty constrained to me on this little boat.

SailorGoneBad said:

I am looking at a 1984 Nordic Tug for purchase. A recent survey of the boat recommends aligning engine. What is the level of difficulty or cost. Access to the engine mounts seems pretty constrained to me on this little boat.

Click to expand...

IMO, get it done in a yard with a good history of replacing engine mounts and alignment
This is not something, IMO, is not something you should undertake.

Ski in NC said:

The 3208 is very smooth running motor, I would not spec a drive saver for such. If shaft length is appropriate I would be done with the drive saver and go coupling to coupling.

If you want to retain the drive saver, try to line it up coupling to coupling and then pull shaft back and install the saver. If there is a little misalignment, the saver can adapt to that.

There are also spacer flanges on the market that can go between the flanges for either alignment purposes or for permanent install.

Click to expand...

Do you have a source for the spacers? I have drive savers and one of my shafts is too short to pull the couplers together without hitting the rear strut.

SailorGoneBad said:

I am looking at a 1984 Nordic Tug for purchase. A recent survey of the boat recommends aligning engine. What is the level of difficulty or cost. Access to the engine mounts seems pretty constrained to me on this little boat.

Click to expand...

My propeller and shaft service shop recommended a local technician, he charged me less than $100 to do the job at his convenience. Smaller engine, good access, but the alignment was way off. It shouldn't be an expensive job... Just my experience

motion30 said:

I bought those mounts from go Marine over the Internet. Honestly I don't know what manufacturer they are I just looked at the weight and size. These are heavy engines so you have to make sure the mounts have enough capacity

Click to expand...

Thanks Motion30. I'm taking a hard look at the Isoflex mounts. I currently have 1978 vintage Dual Flex mounts. The studs are obviously pushed forward in the flange cup. Regardless which mount I choose, it will be a learning experience!

Comodave said:

Do you have a source for the spacers? I have drive savers and one of my shafts is too short to pull the couplers together without hitting the rear strut.

Click to expand...

I had one made for my ex boat. Easy job for any machine shop with a lathe that can handle the diameter and a milling machine.

Yea, I just made mine on a lathe and a mill. But have seen commercial ones available, I think some of the drive saver companies stock them, would need to search.

If prop shaft is too short to do a proper alignment, might be worth getting a diver to pop the prop off.

Drive savers are built to break before the engine is damaged.

Do you carry the required bolts to assemble the flanges to get home if the unit functions ?

Or a spare drive saver?

FF said:

Drive savers are built to break before the engine is damaged.

Do you carry the required bolts to assemble the flanges to get home if the unit functions ?

Or a spare drive saver?

Click to expand...

If you don't, you should. I didn't and when my drive saver fractured in a lock in Ottawa, I was without prpulsion on one side. Had to drive 18 miles down the canal to a marina and wait a week for a replacment. However, without a spacer, bolts would have been useless.

"However, without a spacer, bolts would have been useless."

The bolts suggested are to mount the shaft & engine flange to flange , the way the shafts are aligned.

This will work as a get home , the new shaft saver can be installed , eventually.

Spurs and other prop shaft line cutters sell spacers as their product often requires moving prop shaft back. Another source.

I picked up a long ground line (long line gear for halibut fishing) at low tide in the Prince Rupert harbour. Some long line guy must have thrown a major length of line over the side in the harbour at some point? An absolute no, no. It wrapped my prop and eventually broke the drive saver. The drive saver did save the rear gear (twin disc) and engine (3208 Cat) but ripped out the stuffing box. A $7K repair and lost fishing time. In this situation a line cutter on the shaft may have been a better investment
than the drive saver?

I have a flex coupling and have always aligned my engine & shaft with the flex coupling in place.
What is the reasoning for removing it? It is made from a fairly hard polyurethane and the flange gaps can be measured like any steel flange. Am I missing something here?

I didn't see any mention of where the alignment should be done.

Some say in the water, and some say on the hard.

I'm inclined to have it done in the water. Which I will do this year after we are splashed.

We had our 2 shafts replaced, after we had new engine mounts installed (2 sets). I had flexible couplers added which entailed making the shafts shorter. No going back as the props would hit the struts. IF I ever wanted to remove the couplers, but why would I, I'd have to get adapters.

Planning on keeping the flexible couplers, just getting another 1 to carry as a spare.

I saw a mention of cutters added to this thread.

I use a cutter-anode type, so it servers 2 purposes. Here is a link to see what they are (http://www.seashieldmarine.com/prod...ode-line-cutter-assembly-patent-pending-zinc/).

These have worked well for me for about 5yrs and are an economical choice.

Greetings,
Mr. N. Interesting product. How much more expensive are they compared to conventional anodes? Thanks.

I have never has shaft savers and I’ve never had problems but friends have had they and it seems a source of their problems. Not sure what the purpose is other than to correct misalignment. I just align my shaft every few years.

Sacrificial Anode Line Cutter Assembly | SALCA

These are the cutter/anodes I suggested in the previous thread about shaft alignment.

Cost for my 1.75" shafts run around $60ea.

Even changing them yearly, considering I'd be changing the anodes anyway, it's a very small cost for the peace of mind, and the cutters have come in handy several times while cruising the Chesapeake.

Use the subject to Google suppliers.

Bigsfish said:

I have never has shaft savers and I’ve never had problems but friends have had they and it seems a source of their problems. Not sure what the purpose is other than to correct misalignment. I just align my shaft every few years.

Click to expand...

I think they can allow for a bit of missalinment and if you hit something hard can save the transmission

I don’t think so.
They are quite solid but not solid enough for alignment. And not flexible enough for any misalignment ..... IMO.
Align to 2 or 3 thousandths.

The web site for PYI says to check the alignment after installing the flex coupler by rotating the shaft and checking that alignment is within .010 in 90 degree increments around the coupler. They claim that since their coupler is machined rather than moulded that it is more accurate and therefore the alignment can be checked.

Can’t go wrong

Nomad Willy said:

I don’t think so.
They are quite solid but not solid enough for alignment. And not flexible enough for any misalignment ..... IMO.
Align to 2 or 3 thousandths.

Click to expand...

With this advice, but it might be a much smaller tolerance than required. My boat manual call for .007 inches. I think the actual tolerance depends on shaft and coupler sizes.

Gordon

Drive savers

When “Drive Savers” break, to save trans and engine damage, they are shot because they break. PYI makes a similar device that after the breakage allows get home at low speed. It, like the drive saver should be removed to do a proper engine shaft alignment. The PYI coupling will also accommodate several degrees of misalignment which is always present as soon as the engine is put into gear due to the flex in the engine mounts.
As far as engine mount access is concerned we often have to modify wrenchs as well as cut access panels as necessary to adjust or replace them. It also helps to have a second person with the feeler gauge at the coupling while the mounts are adjusted. Have fun.