Morris Minor Owners Club

Does anyone know what the correct size is for the bolts and captive nuts that fix the gearbox cross member to the chassis rail?

The reason I need to know is that on taking out my gearbox, on one side two bolts head been cut off and replaced with welds. One nut remained on the other side but I had to cut the head off as it was just turning in the thread without moving.

Intention is to knock out old nuts and weld new ones in.

Steve

IIRC the top ones are 1/4" and the bottom ones are 5/16". They're all fine thread but I don't know if they are BSF or UNF thread. If you're replacing you could make them whatever you want.

The 4 gearbox x-mbr bolts that fit up from under the car are 5/16" BSF, but can be changed to any 5/16" thread or even 8mm could be used if you are replacing both parts - so long as you don't mind the loss of orginality.

The top nuts on the crossmember are 1/4" BSF for the brass countersunk head screws that fit the transmission cover, and for simplicity should be replaced with the same thread nut? Otherwise you will have two different size screws to fit, which can be a bit of a pain.