Pot & Trunnion Propshaft Repair?

[Ruairidh Dunford]

It's also worth pointing out that Tony Betts sells superb, and very good value, adaptor plates that can be fitted to shortened or full length Ruby props allowing them to be fitted in place of all fabric coupling type props.

[Chris KC]

Thanks to all for input, but I'd really like to run the car with an original spec propshaft, and as Mike intimates, I believe it can be made to function acceptably well.

As no ideas are forthcoming on how to repair the shaft, and my motivation is more about saving the original parts as anything else, I'll put this one on ice for now.

Chris

[Mark R]

There's a pot and pin on eBay listed in the last couple of days, as usual, no connection.

https://www.ebay.co.uk/itm/Austin-7-seve...SwEaBaHHRL

Regarding balance, I had a 1931 saloon which vibrated horribly above 40mph even if coasting in neutral, I filed out the holes slightly in the correct direction and set it up with a dial test indicator to get it running true. It made a massive difference and was well worth doing.

[Chris KC]

There's a pot and pin on eBay listed in the last couple of days, as usual, no connection.

https://www.ebay.co.uk/itm/Austin-7-seve...SwEaBaHHRL

Regarding balance, I had a 1931 saloon which vibrated horribly above 40mph even if coasting in neutral, I filed out the holes slightly in the correct direction and set it up with a dial test indicator to get it running true. It made a massive difference and was well worth doing.

Thanks Mark. I have 3 pots already so no problem there. Good tip though re balancing - thank you.

[AustinWood]

I believe that the shaft is designed to be constrained by the spherical section running in the cylindrical hole in the pot.
ie The sphere and pot make a ball and socket.
The pin and blocks are there to transmit torque and not to centre the shaft.
When I got my car someone had tried to centre the shaft by putting washers over the pin. Hence the vibro massage. The ball end was very worn. It would need to be built up and machined to be a good fit in the pot.

[Chris KC]

I suspect you're right Jim. Unfortunately the 'ball' end on my shaft (careful...) is too far gone to take dimensions off. The cost of machining as you describe is likely to be more than it's worth I guess. Incidentally, one side of the 'ball' appears to have a 'notch' machined into it? Or is it just rusted away?

[Dave Mann]

You have just got used to the Seven's characteristics Mike. Chris you could chop the rusty end off and fit a Hardy Spicer coupling as I've done to three worn out carden couplings.

[Annaustin]

I think the hardy spicer type shaft is a well worth upgrade to the original Carden block arrangement due to the lack of full articulation of the carden block.
To refurb the carden joint all parts including the body would need to be hardened and ground to do a proper job.

[Chris KC]

You have just got used to the Seven's characteristics Mike. Chris you could chop the rusty end off and fit a Hardy Spicer coupling as I've done to three worn out carden couplings.

Not a bad idea Dave - at least the front end would look the part and the rest is fairly well concealed. May I ask how you accomplished this exactly? It may perhaps be obvious with the bits in front of me but it's a bit parky to linger in the garage just now!

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I think the hardy spicer type shaft is a well worth upgrade to the original Carden block arrangement due to the lack of full articulation of the carden block.
To refurb the carden joint all parts including the body would need to be hardened and ground to do a proper job.

(All)
Please don't interpret this as a rant of any description (sang froid seems a bit scarce of late! Despite everything else being jolly froid indeed).
However, I'm not (in this case, at least) interested in 'upgrading' the car, but in bringing it back to (something like) original Austin spec.
The balance between originality (conservation) and functionality ('improvement') is a tricky one and each of us treads his or her own path. And over time we may come to see things differently! Thus it has ever been. Equally I reserve the right at any point to suggest politely to another member that perhaps they are going too far - in either direction!
In this specific post though I'm trying to find out how to convert my car from a Hardy Spicer arrangement back to a fabric joint / pot and trunnion, warts and all! I enjoy actual vintage machinery...
Genuine thanks to all for their input.

[cardiffrob]

I've never owned an original propshaft, Chris.  Can you tell me if the 'pin' is a machined part of the original shaft or is it an insert into the fore end of the prop?  Google doesn't seem to have any good close-up shots.

It would be nice to think that you could lathe up a piece of En36 and press it on.