Anyone got one of these selection shafts from the outside of a Busso gearbox?

[Revs]

Before I try and get one made (or try back ordering one from Alfa), I thought I would see if any of you lovely people have a spare kicking around that I can buy.

The shaft where the length of threaded rod from the Corse gear selection system bolts to the gearbox on a Busso V6, well it seems the slightly stiff gear change meant it was flexing the end of the shaft so the lug that the bolt goes through has snapped.

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Adie at AHM helpfully dug out this diagram (with a "how the hell did you break that" :) ), where the part that is broken is part 3, which looks like it will easily come out if I remove bolt 8. So if I could find a replacement, it looks like an easy swap.

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This is a 1989 3.0l V6 from a 164, but in usual Alfa style two possible parts are listed depending on chassis number but the diagrams for 2.5 and even 2.0 turbo look just the same. Hopefully as I'm not hooking it up to a 164 gear lever it doesn't really matter.

Thanks for looking - Richard

[Guy Mayers]

I've just buried a 164 gearbox in the depths of the garage after a day of pre-move tidying. Before it gets buried further I'll dig it out, it's only loosely assembled!

Drop me a PM with your address and I'll pop it in the post this week.

Guy

[Guy Mayers]

And here you go! Seeing as it’s off a spare box I was given by John Davidson it’s free to you too. Postage in the form of a beer next time our paths cross?
Guy

[Guy Mayers]

When you get round to fitting it get someone to check that the mechanism isn't being fouled by the clutch lever arm when the pedal is fully depressed. That's an issue we've seen on Hawks that's resolved by filing off the right angle corner in the bottom right of the picture above, also check the bracket that clamps onto this rod for fouling in any gear, I suspect that's what's caused a sideways load on the rod and caused the fracture/breakage.
Guy

[ProtoTipo]

Having the gearstick assembly rubber mounted, would reduce the flex of the engine mounts acting on the linkage.

[Revs]

And here you go! Seeing as it’s off a spare box I was given by John Davidson it’s free to you too. Postage in the form of a beer next time our paths cross?
Guy


That's amazing, thank you so very much! Fingers crossed there is enough room to do the swap without dismantling everything around it :)

Some rubber gearstick mounts does seem like a good idea. Wonder if I can 3D print something appropriate.

[Strat Fan]

The CAE way of building the Corse gear linkage was to weld a 1/2" unf bolt on to the gear selector arm you have shown.
Welding this on at an angle which points down towards the central tunnel improves the angle of the middle shaft and also much improves the angle that the upper UJ operates at.
I haven't seen one fitted like yours was before but there looks to be a lot of upward motion on the centre shaft which will have contributed to the failure you have seen.
The UJ is also positioned quite a long way from the Alfa shaft which is adding a bending moment to the bolted part as well.

[Revs]

The CAE way of building the Corse gear linkage was to weld a 1/2" unf bolt on to the gear selector arm you have shown.

Well I will have an old broken linkage shaft soon for target practice and have access to a MiG welder, so will have a think about that. The gear change has always been a bit of a problem in this car, so suggestions for improvements are very welcome. I wonder if we could do with a build wiki to organise nuggets of build info like this.

Interesting photo with a rather familiar engine bay, I presume that is my car in Mick's garage back when he was building it :D

[Strat Fan]

Interesting photo with a rather familiar engine bay, I presume that is my car in Mick's garage back when he was building it :D

Yes, one of a few pics I have from back in the day when Mick was building the car.

I'll drop you a PM

[Revs]

Drop me a PM with your address and I'll pop it in the post this week.


Part has arrived already, many thanks again. Hopefully I'll get to try it later.

[Guy Mayers]

Wow. Second class post sent Monday and arrives Tuesday. Well done Royal Mail!
Guy

[ProtoTipo]

The C503 mechanical shift gearbox (as in Alfa 164 and Delta 4WD/Integrale) was given a cable shift. (as in some Fiat Coupes and the Alfa 155 12v 2.5 V6)
This was before the later cable shift boxes (C530 and C630, as used with later Bussos)

So in theory, it could be possible to fit the C503 cable shift selector to a pre C503 mechanical shift gearbox.
If that was possible, it would get you round the problem of the 164 mechanical selector shaft operating at the wrong angle for a mid engined car (but the right angle for a FWD car)

[ChrisCar6]

The C503 mechanical shift gearbox (as in Alfa 164 and Delta 4WD/Integrale) was given a cable shift. (as in some Fiat Coupes and the Alfa 155 12v 2.5 V6)
This was before the later cable shift boxes (C530 and C630, as used with later Bussos)

So in theory, it could be possible to fit the C503 cable shift selector to a pre C503 mechanical shift gearbox.
If that was possible, it would get you round the problem of the 164 mechanical selector shaft operating at the wrong angle for a mid engined car (but the right angle for a FWD car)

Now that is useful information Chris!

[ProtoTipo]

Now that is useful information Chris!

A bit on the theoretical side Chris, for now.
Here's a photo of a C503 cable shift box: You can see the redundant mechanical shift webs on the top, just like a 164 gearbox.

[Revs]

When you get round to fitting it get someone to check that the mechanism isn't being fouled by the clutch lever arm when the pedal is fully depressed. That's an issue we've seen on Hawks that's resolved by filing off the right angle corner in the bottom right of the picture above, also check the bracket that clamps onto this rod for fouling in any gear, I suspect that's what's caused a sideways load on the rod and caused the fracture/breakage.
Guy

So a progress report, I ended up with an unexpected twist on the above.

The new (to me) rod has the M8 bolt hole that's half way down something like 20mm further down the rod than the old one. That pushes the coupling bit well into the zone of the clutch arm, so attempting to select 2/4/rev collides.

I have a friend with a pillar drill, and I have an M8 tap and die set. Hopefully we can get it sorted tomorrow.

[Revs]

Final update and another thank you: The wife and I just took the car for a trundle to the local Laithwaites and successfully made it back with a boot full of wine so all working again :D

The new hole in the replacement shaft (for bolt 8 to go in on the diagram at the top of the thread) worked a treat. When putting it all back together, I realised that when selecting 2,4,R the M12 threaded rod that goes through the aluminium block was just hitting the bush that my new shaft was sliding in, making it hard to select those gears. Looking at the chunk worn on the bush, it had been doing this for as long as I have had the car.
So, threaded rod back out, saw 5mm off the end, put it all back nice and straight rather than the slightly odd angle it always used to be and the gear change is so much better than it has ever been before!

Best go book a ticket for the AGM now I've got a car to turn up in :D

[john]

Sounds like a result in anyone's book that does!

[Guy Mayers]

Glad you're back on the road!