sunrise 35 shaft drive lenght

[zmlade]

I'm a new owner of sunrise 35, and I need to change shaft - previous owner has not installed zinc anodes, and he didn't care much during Covid, so it is corroded beyond repair.

I do want to change cutlass bearing, shaft and shaft seal (Volvo) fast, while on lift.  So I have to source all parts upfront. Does somebody have info on shaft length (shaft diameter is 25 mm) and cutlass bearing outer diameter with its length? I expect 1,5m for shaft length and 40mm for cutlass bearing outer diameter.

Any other information on that matter is very appreciated!

Thanks, Z-

[rene460]

Hi Zmlade, Congratulations on your purchase and welcome to the forum.

Unfortunately, I don’t know the shaft length dimension you require, I am another who wishes it was included in the manual, as it can’t really be measured without taking out the shaft.  You also need the replacement shaft to be machined with the correct tapers, key ways and threads.  Many have asked about cutlas bearing dimensions in previous threads, dimensions for some models have been posted, but I suspect that most measure the bearing on removal, and find the dimensions available in stock at the yard.  Worth having a new nylon screw to hold it in place when you install the new one.  (Mine was M6 x 1.0 but I don’t know how common that is.)

I have had my shaft out, and replaced the propellor, and from that experience, I do have some comments on your plan to do it all quickly while on the lift.  Can I suggest that you enquire at your yard the costs of having the boat put on a cradle for a few days while you do the work, and only pay for the crane while you are actually lifting out and relaunching.  At our yard, the lift is expensive, but yard fees quite reasonable, and a lower rate for days that no work can be done due to weather or waiting for parts.  I assume reasonably typical.

The critical steps in the job are releasing the propellor from the shaft, and releasing the coupling flange from the engine end, and then doing them up again to the specified torque.  I found a standard puller would not fit between the flange and the gear box and had to get something made up.  I insisted on the proper torques, and it is not trivial to hold the shaft to enable the tightening.  Not insurmountable issues, much will depend on whether parts have been joined by corrosion, but I would not like to be doing it under the suspended boat.  Much scrambling in and out of the boat required.  

Of course, I don’t know your experience level, and you may well be experienced in all this on previous boats, but for a modest charge in yard fees, it will be a lot less stress with the time pressure relieved.  Would definitely be worth it to me anyway.

Good luck with the job, and please come back and tell us how it goes.  And please do post the shaft  length and cutlas bearing dimensions for future owners.

rene460

[Charlie-Bravo]

I would also head for a cradle, as accurate measuring can only be done with the shaft removed, and your machinist will appreciate having the old shaft for accurate taper placement, thread lengths & keyway sizes.
I would find the machine shop first , and give plenty of warning of when you expect to arrive with the old shaft. in the mean time they could order a length of bar overlength if you can give the approximate length, this you could estimate by measuring from gearbox to P bracket fixings internally and add say 500mm or even more, the slight 'waste' and cost of the excess material will be absorbed by less time with the boat in the cradle I would hope, and by giving advanced notice you might get the new shaft made quickly.

The only other way I can think of , and I really wouldn't recommend it , is to lean up against a wall in a tidal harbour, one with little water to give the most time, pop off the prop , remove gearbox end flange ( not always an easy task!) , loosen old gland, withdraw shaft, measure and photograph, and then get the old shaft back in , or fit some kind of plug before the tide comes back !

Everything on a boat invariably takes a lot longer than estimated, things that should just unbolt don't , and the reassemble can be complicated by nuts that crumble , studs that shear when being removed etc. On the hard in a cradle these things just irritate, create an added challenge and perhaps cost yet another days storage, but with an incoming tide and the potential of a flooded boat, scrambling around knee deep in mud ..... well let's just say the cradle would have seemed good value.

Hopfully now convinced that the cradle is a good idea, and as the boat is new to you but not new, you might replace all below water through hull fittings if their age is unknown, and if required add some fresh antifoul to make the most use of the lift,  then you can relax afloat and enjoy dry bilges for years to come.

Congratulations on your purchase.

CB