4 replies to this topic

[BMC]

What type of thread is needed if i want to get a new knob for the gear stick or are they all the same on all cars?

[Gremlin]

I want to know if the quick shift threads are M12?

[alex-95]

The tap size is 5/16 UNC or  bsw

Edited by alex-95, 01 October 2013 - 08:38 PM.

[tiger99]

Which transmission, i.e. age of car and magic wand, remote or rod?

 

On the early "magic wand" or remote it is actually BSW, commonly called Whitworth, but is sort of compatible with UNC, although not if highly stressed, so in that application either is ok. (Bit of history, the knob dimensions dated from the Morris Minor, which was all BSF with some BSW. I know that because I cannibalised bits from one many years ago and the bolts were all grade R, which was normally only used on BSF/W, whereas early Minis were grade S, which is used on UNC/F, and is effectively the same as ISO grade 8.8. There are supposedly several other "historical" BSW threads on a Mini.)

 

But check the diameter with a ruler, 5/16" seems a bit much to me, I thought it was 1/4". Prove me wrong, if I am, it was a while since I handled one that old. The later rod shift may be 5/16".

 

There is then the dilemma of the locknut, if it has one under the knob. These were fitted originally, up till 1964 or thereabouts, so the knob would be rotated till the H pattern lined up with reality, and then tightened, but they often got lost and the knob ended up screwed on tight with the markings facing in some arbitrary direction. The question is, will the nut need a BSW or "AF" spanner? My memory says that it is made to AF hexagon dimensions with a BSW thread, or was on my oldest Mini. Somewhat odd, but there is another (large) bolt somewhere in a Mini with a BS (55 degree) thread profile, and an AF sized hexagon. I should say no more as it usually triggers a huge argument.....

 

Oh, and by the way, some modern plastic gear lever knobs can be forcibly screwed on regardless of the actual thread, and many a time others which were oversize have been filled with epoxy and pushed onto a lightly oiled thread. They then will hold securely, but can be unscrewed when required. A common but effective bodge.

[BMC]

Thanks, its a 1994 SPI, im guessing its a rod. And im after a new polished alloy one, Already have a round one with a union jack on it but want something diferent.