Gearbox floor panel screws

[jaguar68]

Hi Guys,

does anyone know the thread used on the 32(?) brass screws used to hold the gearbox floor panel is?

Regards

John

[simmitc]

1/4 inch BSF

[mike.perry]

Chuck them away and use 7/16 AF headed bolts, they are a lot easier to undo with a socket and ratchet.

[linearaudio]

Chuck them away and use 7/16 AF headed bolts, they are a lot easier to undo with a socket and ratchet.

?? Wouldn't 1/4" (3/16"??) BSF have a slightly larger head size than 7/16" AF? Or do you mean re-tap the holes to 1/4 "unf? Only wanting to check because of my present frustration:- I had a lovely, lovely, 1/8" & 3/16"BSF open ended King Dick until it vanished in one of those black holes recently.... 7/16" AF spanners don't quite fit BSF fixings unless they are "sprung" through use, or someone has cheated with the hex size when making the bolts!
And why is there always this odd sizing with BSF/BSW spanners? Grrrr.

[mike.perry]

The bolts on my MM gearbox cover have 7/16 AF heads, the threads have not been retapped. I still have brass screws on the Traveller so I will compare the threads.

[jaguar68]

I have them all undone (eventually) and have the new screws to replace them. I want to run a tap down the holes to clean them up before repalcement. Using bolts might be an option on the floor of the Split Screen though.

Does anyone have experience of the "Dum Dum" sealant turning into a sticky slime? Also, what is the best way of replacing the sealing material?

Regards

John

[Alec]

Hello Linearaudio,

the reason for the apparent conflict between BSF and BSW spanner sizes is simple, it was to save metal during W.W. 2. What they did was go down a head size for a given diameter, e.g., 5\16" B.S.W had the same head size as 3\8" B.S.F, now the head sizes are the same but the spanners are still marked the old way.

Alec

[mike.perry]

I have checked and the bolts I used are 1/4 BSF - 26 TPI with 7/16 AF heads. Much easier to spin down with a socket and ratchet. I haven't bothered with sealant, the lubrication from the engine keeps the threads free