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Hello

I have a 1984 CS 36 T with a Westerbeke W33 and Vdrive. The shaft sits about 1/16 inch low in the stern tube, not quite touching the bottom. I am assuming that the mounts may have compressed over 30 years and 3200 hours. Do I need new engine mounts, or should I just raise the engine and align? The engine mounts appear to be OK and there is no excessive vibration. Cutlass bearing appears OK. I was told by a dealer who has not seen the engine mounts that 30 year old mounts will need to be replaced and that raising and aligning the engine is only hiding the problem. Is he correct?


Any advice is much appreciated.

Thank you Mutt
 

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One of None
Hunter 34
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adjust, new mounts would also need to be adjusted, so either way someone gets practice at it!

Dealer says "let's make some money on this one"

it is typical to replace the cutless, shaft seal/s engine mounts in a boat that is getting older. so if it's is your budget do it.
 

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Dirt Free
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Just because the shaft is not centered in the tube does not mean there is an issue, it most likely left the factory that way. As long as the alignment checks out and there is no vibration, leave it alone.

If you use the boat like most Lake Ontario sailors (20- 40) hrs a year the mounts are probably serviceable. If you are going to cruise, then invest in new mounts.

Take a look at the rubber in the mounts an look for unequal compression or cracks. If you can squeeze the rubber slightly then once again they are probably serviceable.

I have not looked at it in some time but I think I may have more on this topic in Marine Survey 101

PS. The CS36T is in my opinion the best built production boat on the water.
 

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Most engine mounts contain 'a rubber' to accommodate adverse motion. All 'rubbers' when under pressure slowly deform over time through the process of 'creep' - permanent plastic deformation. This continual change of dimensions due to the engine's weight/mass will continually & progressively cause sag of the mount; hence misalignment. This sagging of the mount will progressively become larger and larger as the rubber in the engine mount ages.

Most high level transmission mechanics and power train designers suggest replacement of the engine/transmission mounts on a periodic basis .... usually recommending motor/transmission mount changeout starting at 5+ year intervals (and whether the power train is operated or not!!!).

The same applies to automotive - car/truck applications, especially where 'universal joints' are used in the 'power train' and which no longer produce 'constant' rpm output after quite small elastic deformation in the engine/transmission mounts, causing 'misalignment' to the universal joints and which then results in progressive adverse wear on seals, gearing, etc. in the transmissions, differential, etc.
 

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The engine beds are identical, nothing wrong with it, I measured them and everything look just find. The engine that is mounted higher...they put a couple of metal pieces to lift the mounts, the engine almost touches the engine compartment hood. But I cannot find why they did it, and the people that did it, are no longer around (I bought the boat not so long ago).

I would have guessed that if one engine is mounted higher, its shaft/propeller would have been pointing lower (higher angle/more vertical) than the other engine shaft/propeller, but it is not, they are both at the same height, same measurements. This have me wonder, if I lower this engine to the "normal" position, so it can be seating at the same height as the other, would its shaft/propeller then point higher than the other?

The engine that is mounted higher, vibrates much more than the other, and this I don't like!

Sorry to hijack this thread but I am new to this forum and don't know how to create a new thread
 

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...........

I would have guessed that if one engine is mounted higher, its shaft/propeller would have been pointing lower (higher angle/more vertical) than the other engine shaft/propeller, but it is not, they are both at the same height, same measurements.
This have me wonder, if I lower this engine to the "normal" position, so it can be seating at the same height as the other, would its shaft/propeller then point higher than the other?
A one or two, etc. degree propshaft difference caused by differing engine heights isnt going to be visually noticeable in prop angle, especially the closer the cutless bearing and strut is to the prop.

The engine that is mounted higher, vibrates much more than the other, and this I don't like!
If the boat is on the hard - remove the packing and be SURE that the propshafts are running close to the center of the sterntubes and dead center of the stuffing box(s); then realign the vibrating engine & repack the stuffing box and recheck the alignment; plus, put a dial indicator onto the propshaft and look for propshaft being 'forced' sideways or up/down by the packing being symmetrical/unsymmetrical in the stuffing box; then launch the boat and recheck engine alignment using the same methodology.
If the stern tube and/or the reinforced rubber hose that connects the sterntube and the stuffing box is a wee bit twisted from 'true', the packing can put a wee bit of 'side pressure' onto the propshaft which can cause the shaft to 'whip' (precess like a jump rope) under certain (harmonic) rpms.

Simple speak: realign the offending engine .... carefully. If the above doesnt affect a solution, then check the coupler and 'drive saver' faces and flange outer dimensions .... with the coupler disconnected and using a dial indicator on the face of the coupler and at the OD of the coupler; AND, at the face and OD of the propshaft coupler while turning them by hand - all to check that the coupler and/or 'drive saver' is running 'true' in all three axis - If the faces of the couplers and drive savers are not 'true' and 'exactly parallel', that also can cause 'shaft whip'.

;-)
 
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