Rear bumper mounting stud thread

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stag-gered
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Joined: Tue Jul 20, 2021 4:43 pm
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Rear bumper mounting stud thread

Post by stag-gered »

Hi,

Can someone help with the nut size for the threaded end of the rear bumper mounting studs please? The existing nuts take a 7/16 W 1/2 BS ring spanner. New 7/16 BSF nuts from Moss (as per their parts catalogue) were too small and the replacement 1/2 BSF nuts from them will take two complete turns on the tread before locking. The existing nuts run up and down the thread easily by hand, so nothing wrong with the thread. ESM list the nuts as 1/2 BSF. I am thinking that the nuts must be 7/16 Whitworth, but can anyone confirm? Unfortunately I do not have a thread gauge.

I could re-use the old nuts, but they are quite corroded, so it would be nice to replace them.

Thanks in advance.

Stag-gered
philthehill
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Re: Rear bumper mounting stud thread

Post by philthehill »

The bumper iron nuts are 1/2" BSF threaded with a 7/16" BSW/1/2 BSF spanner required.
Most BSF threaded nuts on a Minor have Whitworth size heads.

Here are a pair of nuts and washers from e bay

https://www.ebay.co.uk/itm/173863666474 ... SwCKxaldpH

stag-gered
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Posts: 21
Joined: Tue Jul 20, 2021 4:43 pm
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Re: Rear bumper mounting stud thread

Post by stag-gered »

Thanks for confirming the size and stopping me heading off in the wrong direction. I have tried the new 1/2 BSF nuts supplied by Moss on the front bumper irons and whilst again they lock up after a couple of turns, with the spanner they go past this point and then run up and down the thread okay, but remain tight in this one spot. Odd.

Anyway, problem solved and thanks again.
philthehill
Minor Maniac
Posts: 10768
Joined: Thu Jul 19, 2012 12:05 pm
Location: Hampshire
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Re: Rear bumper mounting stud thread

Post by philthehill »

I would suggest that you need to run a die nut down the threads.
Here is one for sale if you do not have one:-
https://www.ebay.co.uk/itm/334011144440 ... SwrRpgqlN9

When working on a Minor a good set of BSF taps and dies is a bonus.

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