Gearbox crossmember removal

[KenFern]

I am looking to remove my engine and gearbox (1970 4 door) but when i came to remove the gearbox crossmember 3 bolts came out ok but the last has the captive nut spinning in the chassis member and of course its the one under the brake master cylinder. My question is...is there a special trick to get it out without removing the master cylinder which i dont want to do at this stage, has someone solved this problem as i cant be the only one its happened to

Thanks

Ken

[bmcecosse]

Maybe if you take the gearbox cover off inside the car. Or - just shear the bolt with a good sharp thin chisel!

[MarkyB]

Sounds about typical, the most awkward one won't come out.
Even if you grind the head off and get the gearbox out, you still need to replace that bolt.
I'd suggest you bite the bullet and take the master cylinder out.
Lever the torsion bar down and remove the bolts that hold the cylinder into the chassis leg.
Then undo the pipe into the back about a turn, enough for it to release it's grip on the pipe anyway.
Then undo the bigger bolt that goes into the master cylinder.

Move the master cylinder towards the pedal until it is free and lift it out.

Penetrating oil onto the turning nut, cup of tea or two, then try Mole grips onto the outside of the captive part with as much strength as you can muster.

If this doesn't do the trick, tool purists look away now, try hammering a screwdriver between the chassis and leg until the nut can't turn.

[les]

If you're keeping the car for any length of time I would suggest removing the captive nuts and cages completely, and replace with a piece of flat bar quarter inch thick drilled and tapped to 5/16'' bsf set the correct distance apart and drop this, coated with grease, in the chassis rails. If you make the metal the same width as the rails ( with radiused ends to stop it cutting in) it will be secured in place.