365 GTC clutch release bearing

[Colin Angell]

Hi there,

I am in the process of changing the thrust bearing on my 365GTC. The bearing is held in a steel hub which slides along a support tube when the clutch is operated. The back of the hub appears quite worn where the clutch lever presses against it and I was intending to build up the worn area in weld and re-machine the flats. Has anyone done this and are there any pitfalls?

Thanks

Colin

[tyang]

Hi Colin,

Why not buy a new release bearing? Is it not available? Can the cost of the welding and machining match the cost of the new part? Will the heat from the welding affect the bearing?

Tom

[zac]

I think what Colin is referring too is not the bearing itself but the holder that the bearing presses onto. If it is indeed that worn and a replacement can't be found I guess you could repair it. I would be very carefull and check the surface hardness of the release arm and sure that you repair can be hardened to match otherwise it will wear even quicker. Ferrari has a nasty habit of making some very hard parts and when the replacements aren't up to spec is where people run into trouble. The bigger question for me is why is that piece so worn?? You want to make sure it slides nicely on the support tube that covers the input shaft and that the pressure plate does not have interference issues.

Zac

[Colin Angell]

Hi Zac, You were quite right in your assumptions. I attach a photo of the thrust bearing carrier and the worn area can be clearly seen. The carrier slides quite freely on the tubular shaft, so there is no problem there. It just seems that the end of the forks are much harder than the back face of the carrier.

engine work 4 016 small.jpg (84.89 KiB) Viewed 4775 times

. I have not been able to find a replacement so I had intended to buid up the face in weld and re-machine, prior to hardening and tempering again. I was hoping someone could let me know how hard the back face and internal bearing surface should be. Failing that I have heard that these carriers have sometimes been made in Bronze and would be fairly easy to manufacture.

Colin

[jcwconsult]

I had the same issue on my 2+2 and had to replace the sleeve. Terry Myr found the right part through his contacts and it was NOS with the original cosmoline covering.

[Colin Angell]

This little problem sent me down a side alley which sheds a little light on the joys of restoring these old cars. I am overhauling the engine of my 365 GTC and while the engine block is away being machined I have been trying to sort out all the ancillary parts, including the bell housing and clutch assembley. I tried to buy a new thrust release bearing and carrier from Maranello Parts and was told they only had the thrust bearing. I tried one or two other suppliers without success and thought, "oh well, I'll restore what I've got", hence my original post.

I didn't get an instant response (strange how we expect everything straight away now) and had the bit between my teeth anyway, so I just decided to get on with it.
I built up the damaged faces in weld, 1 night.
I don't have a milling machine, so I made a jig to hold the carrier on the cross slide of my lathe, 2 nights
I then sorted out a flycutter to re-machine the flats, 1 night
I then ground a lathe tool to reform the semi-circular groove for the spring clip, 1 night
So by that time I had spent a week of evenings in my garage focusing on this one item and it was almost finished. The next day I was back at Maranello Parts for something else and I happened to mention the carrier to a different chap and it turns out they have about 130 old stock parts sitting on the shelf in their Original wrapping. I bought one!