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A disc of thick steel like cvta used, except the middle bored out so it slides over the threaded section of your hydraulic puller and 6 bolts long enough to fasten onto the coupling while sandwiching the puller's spider. That along with a large blow torch, not a dinky little creme brulee torch with a canister, will shift it.
I had the same problem when trying to remove the coupling on my Broom. After trying just about everything, I hired a 25 ton pump and cylinder set from Dutest in Basildon, Essex. I made up a plate and used high tensile studding to leave a gap to get the jack in. It worked!
You may be able to hire something similar from a company more local to yourself.
Cover the set-up with an old duvet or similar when applying the pressure. It does make a good bang when it lets go.
The job now backs to my hands as the boatyard said they can't do it in the coming week. I am going to order a grinder, a 10-ton hydraulic cylinder, a bigger gas torch and bolts. Just need to find a piece of the metal plate at least 15mm thick.
I am afraid the 10-ton hydraulic cylinder is not strong enough, but after measure, the coupling sizes between the two bolts maximum size is 80mm. It won't be able to fit a bigger cylinder in. The 10-ton cylinder size is 83mm X 63mm x 56mm (L*W*H).
I suggest you use 4 lengths of M20 HT threaded rod (Screwfix). You also need some 20mm thick mild steel plate (ebay).
Drill the plate so that the holes will clear the base of the 25 ton cylinder. You will need to angle the holes inwards slightly so that all 4 lengths of studding taper together at the coupling. If you can't get the studding through the coupling holes then you need to make up a back plate to get behind the coupling flange.
Just a thought.
In one of your pics, there seems to be a keyway (it must be a keyed shaft or the flange would turn on the shaft)
Have you tried to knock the key out.
Maybe the key itself is tapered so maybe it could be knocked out from the propeller side of the flange.
Please keep us posted with your progress.
before you spent more money on press kit that you'll never use, maybe you should see if there's another coupling you could buy for 100quid and cut the bastard off!
I still bellieve proper heat will do the job, so looking forward to the success story soon!
Always take care trying to move a key, too much hammering/tapping/drifting can end up with damage/swelling to the key making matters worse.
For info re removing couplings there is a thread going on in the PBO forum at the moment mainly about R&D type but interesting Removing shaft from R&D coupling
@vas Yes, that's why I have bought a grinder to get ready to cut. Should deliver today.
This old bastard coupling is hopeless. Tight, no hydraulic puller can fit, even the smallest hydraulic cylinder also can't fit in because the 6 bolts space is limited. So the last chance will be heating a lot under a DIY 20mm thick plate puller in the next coming days. If this failed, then I should practice my grinder skills.