Yes, that is an important structural member. The MGB has no frame, as
such, it is unibody construction like all modern cars. Replacement metal
parts are available from the usual suppliers that can be welded in,
but... if that piece is that far gone, it is likely that the sill and the
floorboard are also dubious. You should take out the carpets to examine
the floors, and poke around underneath with a pointy screwdriver and a
magnet to determine the full extent of the problem.
One question: were you jacking it up using the original jack and jack
socket, or were you using a floor jack or bottle jack under the frame
member (not recommended)?
Dan Ray had this to say:
>Any Advice from the list for Greg? See the message below.
>From: Greg Kulik <firstname.lastname@example.org>
>To: email@example.com <firstname.lastname@example.org>
>Date: Friday, December 10, 1999 9:47 PM
>Subject: 76 MGB
> My son and I recently bought a 76 MGB. Not too much surface rust, but I
>noticed something underneath that troubles me. The channel that runs the
>length of the car under the door sill is pretty well shot. I tried jacking
>it up on the passenger side and I heard some crunching. I was wondering how
>difficult it is to reinforce this member. Will I have to take the whole body
>off of the frame?? Is this even possible? Any information that you can
>forward to me will be greatly appreciated.
>24 Longvue Circle
>Ambridge, PA 15003
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the red one with the silver bootlid.