Thread (TPI) Details Required

[thunderbolt]

Can anyone help me with the TPI and thread type (UNF, Whit,etc) for the following nuts on a '74 Mk2 Roadster please?

Gearbox mainshaft nut - holds the clutch centre in place (04.0373);
Clutch adjuster nut (06.0005);
Engine crankshaft nut on drive side - holds rotor in place (06.4680).

Thanks

Cheers Don

 

[L.A.B.]

http://stainlessbits.com/link12a.html

"04-0373 NUT CEI 5/8"x 20".
(If the thread was changed from 20 CEI (BSC)* to 20-UN then they didn't change the part number).

"06-0005 NUT UNF 1/2"x 20".
"06-4680 NUT ??? 5/8"x 20 ROTOR" (Probably 20-UN if not CEI BSC)

*Later edit: If it is 20 TPI British, then 5/8" x 20 is more likely to be 20 TPI Whit Form as the 20 CEI/BSC series was obsolete by this time.

 

[thunderbolt]

Thanks Les,

That was my problem - on a late model Commando I wasn't expecting cycle threads except inside the engine.

 

[thunderbolt]

Another quick one on a different subject:

What is the best way to rotate the engine forward and backwards to check TDC and set the ign timing statically using degree wheel.

Is it by rotating the back wheel with the gearbox in top gear (I have belt drive).

I am finding when rotating the crankshaft rotor nut anti clockwise to rotate the engine forward the nut simply undoes.

Any advice gratefully accepted.

Thanks Don

 

[MichaelB]

Top gear, rear wheel works for me.

 

[L.A.B.]

I am finding when rotating the crankshaft rotor nut anti clockwise to rotate the engine forward the nut simply undoes.

It couldn't have been very tight (manual says 80 ft.lb. for the rotor nut, OldBritts and Mk3 manual say 70 ft.lb.)?

 

[thunderbolt]

It couldn't have been very tight (manual says 80 ft.lb. for the rotor nut, OldBritts and Mk3 manual say 70 ft.lb.)?

OK simple solution. I admit that I didn't have it done up that tight as the plastic Wassel degree wheel was in danger of disintegrating.

Also I was wanting to compare the 31º ign timing off the degree wheel with the 31º reading off the degree scale riveted inside the primary outer case for future reference. I reckoned with that nut done up super tight I would have trouble getting it undone without moving the crank so the degree wheel could be removed and the outer primary cover fitted to read off the factory degree scale.

Thanks Don