I am not happy with how the leather on my gear lever has turned out. Cleaned it a couple of times but after a short time it feels sticky again. So I decided to make a new one. Grabbed a piece of firewood and turned it down to a round shape
Very nearly drilled and tapped it M8 but then decided that didn’t look quite right. Turns out the thread on the MANUAL cars is not M8 as it is on the automatics. This poses two questions:
a) Why the … did they do this?
b) What exactly is it? It’s not M8 x 1.5, but close to 8mm diameter and close to 1.5 pitch. So it probably is 18tpi, either 5/16 BSW or 5/16 UNC.
I reckon UNC:
BSW would be perfectly believable in the way that some other one-per-car threads did (e.g. the upper camchain adjuster nut on the XK engine). I found my original Jag 5-speed Getrag knob and will check if it’s 8mm
Thanks for checking and thanks for the offer Pete!
It is probably cheaper to buy a tap here than your postage would be, I think I’ll go with that option. Maybe I’ll need your help with something else in the future
Can you tell if it really is BSW? I am not sure if UNC would also kind of fit a BSW thread and vice versa.
In theory the BSW thread should have rounded tops and the UNC flat, but I think in practice they are both rounded and at least I have trouble telling them apart.
I screwed the knob onto both UNC and BSW taps The BSW has rounded tips and is old but still sharp and the UNC is a cheap Japanese with sharp points, not flat, so maybe not a fair comparison. Either would work and of course you would get more use out of a UNC tap.
Thank you Peter!
I thought the threads might match close enough for both bolts to fit without interference, but never thought that even both taps would screw in with neither cutting any material.
I ordered a BSW tap, its a British car after all
Also found an information (no idea how trustworthy it is) that up to the 60s they used 5/16 BSW - no mention of UNC at all.
Now that is a nice car! Maybe I should have invested more time and money and got a manual XJR
I am curious now and will try and measure the thread angle. Not sure if I will manage to be exact enough to tell the difference between 60° and 55°, but I’ll give it try.
Looking good, maybe a light shave and some varnish or “dye” like you suggested. All the walnut is also varnished and it gets darker too once you apply any laquer or shellac, try it by just getting the surface wet with terpentine, you’ll see!
I bought a BSW tap and borrowed a UNC tap. There really isn’t much of a difference, but I lean towards it being a UNC thread. So that’s what I tapped now.
I glued the brass insert into the wood with epoxy glue. It did look darker where the epoxy was, still not dark enough though. I have some walnut dye on the way. Will try that when it arrives.
That is intermittant though. I need to work on it. I work for the company who made the clock (albeit in a completly different division) and had the last few LCDs shipped over when they cleared out the stock. The issue is, that the tooling to attach the heat seal ribbon to the LCD and the PCB had been scrapped already. So I need to make a tool to do it.
Lots in the archive involving tightening the ribbon grip by pressing in a card behind it, as I recall. Which is not the same as using a credit card to purchase a solution i
