Can anyone help me, as a new member as of today. I bought a 71 morris traveller an the crankshaft pully bolt was stripped I bought a new one but am having trouble determaning the type of thread is it A/F or UNF? as I will have to tap out the end of the crankshaft.
Regards davidmtr71
Cranckshaft
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davidmtr71
- Minor Friendly
- Posts: 20
- Joined: Thu Feb 23, 2012 3:57 pm
- MMOC Member: No
Re: Cranckshaft
I will try to find out the thread for you - but this is a MOST unusual fault......how did this happen??? There is no such thing as an 'A/F' thread......... I think the thread is 5/8" - but I will try to check that on a Mini forum. I know on high power engines the bolt (starter dog on a Minor) is very often replaced with a longer Allen cap screw.
Ok - research shows it is a very special 5/8" X 16 TPI Whitworth Form thread - note that is NOT a normal Whitworth thread....... You will need a very special tap to sort the threads if they really are stripped in the crank nose........
Ok - research shows it is a very special 5/8" X 16 TPI Whitworth Form thread - note that is NOT a normal Whitworth thread....... You will need a very special tap to sort the threads if they really are stripped in the crank nose........
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davidmtr71
- Minor Friendly
- Posts: 20
- Joined: Thu Feb 23, 2012 3:57 pm
- MMOC Member: No
Re: Cranckshaft
Replybmcecosse wrote:I will try to find out the thread for you - but this is a MOST unusual fault......how did this happen??? There is no such thing as an 'A/F' thread......... I think the thread is 5/8" - but I will try to check that on a Mini forum. I know on high power engines the bolt (starter dog on a Minor) is very often replaced with a longer Allen cap screw.
Ok - research shows it is a very special 5/8" X 16 TPI Whitworth Form thread - note that is NOT a normal Whitworth thread....... You will need a very special tap to sort the threads if they really are stripped in the crank nose........
Thanks for your input the thread is a 5/8 crankshaft dog was in the crankshaft when I bought the car but when I tried to turn the engine over with the starting handle the dog just turned and when I took it out I found that it was stripped I have a feeling that the (origional) dog may have been the wrong thread as well, I have cleaned as much of the threads out in the end of the crank as I can but now I need a tap to cleer the way for the new dog, but the new part on inspection by an exellent suplier of nuts and bolts spent some time trying to determine the thread type and it would appear that the new part may have the wrong thread on it? This was bought online from a Morris Minor spares supplier, Can I get another from the MMOC?
Regards Davidmtr71