Clutch shaft replacement

[TR_Jim]

I'm replacing the clutch on my TR-4A, and also replacing the clutch shaft, fork, etc. I bought the fork kit from TRF and the shaft is different from my old one. My old shaft has a groove cut in it on the end away from the slave cylinder for a retaining screw, the new shaft doesn't have a groove. Is the retaining screw necessary? Anyone use this shaft without the screw?
I noticed in the TR6 catalogs that retaining screw isn't used. Opinions please!
I attached a pic of the shafts.

 

[Don Elliott]

On the early cars, there was a grease fitting. I can't remember which end and I assume that the groove was to let the grease get in. The retaining screw that secures the shaft is in the bell housing body and is located 90 degrees to the shaft at the far end. The TR6 does not have a grease fitting. Was it eliminated to cut costs ?

 

[TR_Jim]

Thanks for the input. My clutch shaft doesn't have grease fittings. The retaining bolt in the bellhousing fits in the groove to keep the shaft from moving sideways. I imagine this would only be needed if the tappered pin breaks and the shaft is free from the fork. I'll try cutting a groove in the new shaft tomorrow.