help to disassemble flex coupling

[yelbis]

Please help. I have been trying to strip down the flex coupling on my Dehler 34 1990 as realignment of the shaft and a new stern gland boot is required. I have read a post on the forum describing the three threaded holes in the face plate that take M10 bolts that once screwed in will release the tapered collet and the shaft removes with ease. An engineer has taken a look and confirmed that this is likely the case but not seen this model in 25 years in the trade. Another has stated that it may take a long time, not exactly familiar and when asks him to quote he replied 'forget your pension'.

I have tightened the bolts as tight as possible and nothing has happened. I do not know if the threaded bolts are for collet release or for an extraction tool, therefore is it a push or pull. To take the whole unit out from the opposite end means taking the base of the bunk out.

Is anyone familiar with this unit please.

 

[doug748]

That looks like a Centaflex CF-M-127 (or a close relative) see here:

http://www.tnorrismarine.co.uk/centaflex.php

Cor, those bolts look big, do they engage all the way? Tighten them with a spanner and the collet should fall out.

I think your engineer needs to go on a refresher.

 

[sarabande]

would it be worth applying some gentle taps of a hammer to the flat plate area to help break the bond ?

 

[Tranona]

That is a Centaflex coupling, also sold by Vetus. You will find information about it on p49 of their catalogue www.vetus.com

 

[lcyachts]

To remove the prop shaft (or the driven shaft) from the Centaflex CF-M-127, remove the screws around the shaft locking collar on the output side of the coupling (usually the aft-facing side of it). Then, using the three threaded holes which had no bolts or screws in them (they may be covered with dust caps), insert 3 of the bolts and turn them until the clamping collar loosens away from its cavity and begins to pull away from the main coupling. As it comes further out, it will loosen the clamping force on the shaft permitting the shaft to be removed and the collar removed from the shaft after its extraction. For removal of the coupling from its connection to the gear output, access the bolts from the forward-facing side of the gear output flange. The bolts are typically long and run through the gear output flange and into the coupling – with the bolt heads facing forward and the threaded ends facing aft.

If your coupling is a CFM-127 I hope this helps!