I had one of these returned as a core from a customer to whom I had sold a split case. Id like to use it but I have not found where I can get parts for it. Any leads would be appreciated. TIA
Bearings and seals are available from any bearing supplier. Gaskets can be made up. Synchros and not available. Might have some good used ones. Check yours. Mim clearance is 20th. New clearence is 60 th. 40 to 45 th. Is acceptable. 1st/2nd and 3rd/4th synchros can be reversed. Put the best ones in 3rd and 2nd.
These are not easy rebuilds. I've done them for 30 yrs. Mim time for me is 20 hrs.
Heres a pic of my recent rebuild.
Major problem areas, sunchros, output shafts, hubs and forks and of course gear sets. I now reject one out of two as rebuildable.
20 hours sheesh. I spent that redoing a porche 968 6 speed, this looks so much simpler, but not having done it, Ill have to take your word for it. Now Im curious. I really appreciate your input. How many cars are out there still running which have these transmissions? Cannot be many.
The switch over to the split case occured in late 1958 for the 1959 model. According to Greig, approx 45000 tunnel cases were made and only for the 750 series. Many 750s were converted to the later split case (difficult task) and are now being changed back to tunnel case. In the last 3 or 4 yrs I've done 4 tunnel cases.
Biggest problem is parts. Many have come in for restoration and possible retrofit in a 750 series. But long time storage without oil has left the gear set totally rusted and as such not a candidate for restoration. If the box is out of a sprint or spider veloce in all likelihood it's totally clapped out. Not only are synchros worn, I've seen broken output shafts.
If you have done a split case before, I would say a tunnel case is a 10 fold increase in difficulty. Dont let its size fool you, these are difficult boxes to work on. In the factory service manual, there is a list of special tools for this. I've never seen one. A work around has to be done to do this correctly.