Cabrio

Hi Tony, Yes I had already explored having one made and that is why I was on here, I had been quoted a stupid amount. Anyway I have eventually found one, Boulter Marine on the broads, they said they had lots of stuff and dont throw anything so if anyone needs parts please give them a call. The coupling drive I could not do without as it not only drives the tacho but the oil pump of all things, so no options possible other than to replace. The pump shaft has also' had it' due to my attention and have found a replacement from Aquafax- Luton. Again pricey ( and again very rare) for what is but I needed it as it has no splines on it like all the others I found or that were suggested. Thanks to all that tried to help and now back of to France to finish the job I started, simply to change the bearings in the pump,and run the engine so I can winterise it. What nightmare it has been.

Ok guys and thanks again for all the efforts, Some people seem to be getting mislead by not reading the very first post so I shall try something different. But notes to add are , This first photo shows the pump shaft with grooves in the bearings that I cut . You can clearly see the roll pin hole and the grease mark that shows how deep it fits into the coupling shaft. It is in line with the pump body which it slips into and then the impeller is pushed onto it. If you look at this photo carefully the coupling shaft ( on the left ) is resting next to the pump shaft ( that is on the right with two bearings on it ). It has a rounded end with no splines on it as the photos of the other pumps that people are attaching to this post show. The very far right end accommodates the impeller when inserted into the pump. If you look even closer you will see a whole that is drilled into the pump shaft to accommodate the roll pin. If you look at the coupling shaft on the left carefully you will see the hole drilled through that , that accommodates the roll pin. When the piece on the right is inserted into the coupling shaft it travels approx 12mm untill the two holes line up and roll pin is the inserted. The shaft then becomes one piece. as in this photo When they are inserted into the pump casing the impeller end is approx inline withe the face of the pump casing (Right hand side in this photo) and the coupling shaft protrudes out of the left side 55-60mm approx. The coupling shaft the inserts into the engine approx 55-60mm whem pump is fitted. I cant add a photo to illustrate this at the moment as the coupling shaft is with an engineer The engine block diagram ( IT IS NOT OF MY ENGINE) is to purely give an indication to the area the of an engine where my pump and the coupling shaft ( scew piece ) are located. It is not of my engine. Apologies for the size of photos as I cant reduce them for some reason. Anyway hope that makes it clearer for some. I am after the coupling shaft, part 17 in previous diagram Many thanks

Right, I am back again. Thanks again for all suggestions and efforts. Before I came on here I had tried all the obvious places including ASAP and that is why I approached all the wise old heads on this forum. I have tried all other suggestions that have been put forward that I hadnt thought of myself and still no results. It is definitely not a part I shall be buying of any shelf. I spoke with a marine engine rebuilder in who was breaking a bmc engine and he was confident he had the pump attachment but when he saw the photos of the 'coupling drive' he said he'd never even seen one. He was extremely helpful though and couldn't have tried harder to help. So, as of now only one person has said that they have ever seen one. A gentleman who works at one of the many boatyards I emailed recognised it and was going to rummage his garage over the weekend and see what turns up. There is another guy from a classic car specialist who was confident it was from a Nuffield tractor engine circa 1960's. I have already been in touch with the classic tractor parts supplier and no luck there either but he wanted a few days to see if he could come up with any suggestions. It is definitely an engine part, the spigot (small end) inserts 2.5 inches into the engine and engages with something that makes it turn. The wider (end that I cut a piece out of) more than probably drives the taco or something similar and the pump shaft was slid into it and secured with the roll pin and while all the turning was going on the impeller span and pushed water around the engine. Now, because there are no really heavy forces involved and the holes for the roll pin are still on the shaft, would I be mad in thinking that if I filed off any sharp edges and greased it well, would I get away with just putting it all back together ( including the new bearings that started this whole process) and running it like that. Or I could get someone to weld the small squares I cut out back in place and file very carefully, all back to shape and then run it.Because this thing seems rare and I am struggling. I have emailed the Thornycroft website but had no reply as of yet. I think my best bet is to keep looking for an engine that is being scrapped and yes I have tried Boatscrapyards etc. I am also going visit a specialist engineer who seems confident he can make it but assured me in no uncertain terms it was not going to be cheap. I have attached some diagrams that show the 'coupling shaft' part number 17 on plate TK. In the diagram of an engine block it is located 4th description from the bottom on the right hand side, and listed as an auxiliary drive which is very similar to the set up I have. Anyway thanks all, and I shall keep you posted as to the outcome. But please remember if you see an old BMC engine block in the bramble somewhere, call me as I might need a bit off it :-)

Apologies for the late reply as have lots going on at the moment. Thanks to all who have replied and some of the suggestions have been very helpful. Instead of making individual reply's I shall make one big reply to bring this topic to date, Firstly I still don't have the part. Secondly it has many people who have been extremely helpful by the way, scratching their heads. Bugger out of time Shall have to do this later, Ps The part I am after is called a COUPLING SHAFT AND THE PART NUMBER IS 54007693 in the Thornycroft manual.

Dear Sirs, I was looking for some help with a problem I have, I have a 1986 1135 connoisseur cruiser with a sliding roof. It has BMC / Thornycroft 2.5 154 diesel engine, with a Johnson Raw water pump F5B-9002 / 10-24119-2 . The bearings needed to be changed in the pump so I removed it and found that the pump shaft was in two pieces and joined in the middle and held together by a pin. The shaft needed to be pulled apart so that the bearings could be removed and replaced. One half is the shaft that comes with the pump and the other is an Add On / modification by BMC or Thornycroft spiral / twisted part that when fitted extends into the engine and is driven by moving engine parts( forgive my lack of knowledge for technical terms). I could not separate and after applying heat ( probably too much ) and force, managed to turn it slightly then it wouldn't budge. In the end ( after believing it was all part of the pump and I would get a new one with a replacement part) I decided to angle grind apart and see if it did need to be turned apart and was threaded as I thought. Sadly not, and now I have a problem trying to source a replacement part for the pump. The pump I am fairly confident I can replace but I cannot find the modification /spiral twisted part that was made by BMC/ Thornycroft that needs to be added to the pump crank. Has anyone had a similar problem and know where to buy the part I need or where I may possibly get it made or even better have an old one hanging around for sale Any help would be appreciated,