End of year report ..............
My workshop is full of 95% complete projects which is irritating. I hope to get clear in the early new year. Also the Gearcutter was in touch about bolt PCD on the parts he is making , so hopefully they will put in an appearance in the new year, getting a job of the bench which has been here nearly a year , apart from a short holiday when it went to Goodwood and got broken some more!!
The Dauph awaits the body shop, no surprises there then. I hope to have it finished and back by FEB, which will give me time to sort it out for Easterish (who am I kidding)
Today I have spent a long afternoon modifying the Detent on 5th gear on a 353/365/385 hybrid. This is an issue common to this Hybrid which is a very rare thing in circulation. I think 5 have been built in the UK 3 by me and 2 by Wheeler over the last 30 years. 4 out of the 5 had issues with jumping out of 5th gear. I have finally traced this out to be because the R8 353 5th top gear sits about 2mm further back in the case compared to the later 365 gearset. There is a lot of travel available on the 353 box to allow for its assembly and for it's interlocking mechanism to be installed. None of this was carried into later production 5 speeds, Which is why the problem exists.
I think I now have the definitive answer to this, but won't know for sure until it is back the car and working
The following pics describe the issue and solution. I hope.............
First pic is the 5th shaft from the box (lower) in comparison to a completely standard shaft.
This has been Ground out, by the other people who tried to repair this issue after I had built it, it had changed hands twice and I had a failed attempt at repair. The top shaft is for an 8mm detent which is what all but the last 353 boxes had. I opened it up to 10mm and succeded in making it slightly worse which was a valuable clue, when I think about it. The owner bought a new endcase which is for 10mm detent , but the issue persisted.
The pic above shows the detent moved back about 2.5mm to allow the shaft to travel further forward to full engagement of 5th gear..
Next up is to weld the forward facing part of the detent, putting as little heat as possible into the shaft as it is case hardened, making carbide tools a must. HSS bounces off.
The big lathe is handy here as it has the rigidity to allow fine finishing.
After much faffing about on the mill it's looking better.....
Then you have to polish all the edges by hand until it feels silky smooth all over!!!!!!!!
In the Movies you would fit it all and that would be it, but it wasn't. I built it up and had succeeded in moving it back about 1mm too far, so it all had to come apart and get fettled until it was spot on. If you look very closely at the first image in the sequence you will note that the right-hand detent has been moved toward it's neighbour slightly this had put me off and made me move it further than it needed.
Moral : Meddling with the actual insides of Gearboxes is an exact task and is not to be undertaken lightly.......
Happy New Year. All the best to all of you for 2023. May all your troubles be small ones................