Gearbox cross member bolts

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Dominic
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Gearbox cross member bolts

Post by Dominic »

Hi folks

Just sheared off a gearbox cross member bolt head - Can anyone please tell me what the bolt thread size is for this location? Also, does anyone have any idea what thread is used for the brass screws holding gearbox cover floor in place?
Thanks,
Dom
bmcecosse
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Post by bmcecosse »

The gearbox X member bolts screw up into 'captive' nuts in the chassis legs. Dunno the thread - can you not take another one out (carefully) to find out ? But since you will need to drill/tap a new thread in the hopefully still 'captive' nut - or - release that nut and fit another, then the old thread doesn't matter much! the brass screws are a strange thread - don't know it either although distant memory suggests UNC thread which in that size (3/8"?) will be near enough same as Whitworth.
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Dominic
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Post by Dominic »

Thanks BM, appreciated!
mike.perry
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Post by mike.perry »

I replaced all the gearbox cover brass set screws with 7/16 A/F head bolts. A lot easier to undo with a socket and ratchet.
simmitc
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Post by simmitc »

Gearbox cover screws to floor are brass 1/4 inch BSF. Ideally crosshead but many new parts are straight slot. Advantages to both. I think that the X member bolts are 5/16 UNF.
polo2k
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Post by polo2k »

for the brass screws I found that a cordless drill was a godsend!
- Ash
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bmcecosse
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Post by bmcecosse »

As small as 1/4" ?? Seem to remember them larger - and yes - a drill sorts them out if they don't unscrew easily.
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Alec
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Post by Alec »

Hello all,

yes, i also go for the cross member bolts being 5\16" BSF.

Alec
Dominic
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Post by Dominic »

Thanks for the info folks, much appreciated

Dom.
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