I don't have a good mental picture of the problem.

If the retaining wall has moved, you will need to excavate all the
soil behind the wall to be able to put it back where it belongs.
It may not totally close due to debris in the crack or other
deformations due to time.

If you just want to stop it from going further and to waterproof
the crack you would still need to excavate the exterior, but only
in the area of the crack.

You can use or hire structural repair to the crack using epoxy.
The failure can have heavy steel angle and/or plate reinforcing
bolted to or through the walls. It may be better to cut the
retaining wall away from the foundation, so that a failure in one
does not cause a failure in the other. The wall can be
waterproofed on the exterior after the repair work is done.

As in so many of these issues, I hope you are just looking for
ideas that you might discuss with the appropriate engineer.

(top posted for your convenience)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Keep the whole world singing . . . .
DanG (remove the sevens)




"Dave" wrote in message
oups.com...
Hello All,
I have a 1920s home with a basement garage. On either side of
the
driveway leading into the garage, there are retaining walls
which are
about 3-4 feet high. The retaining wall on the left basically
continues
into the house and becomes the outside foundation wall.
This left side retaining wall shifted at some point due to
improper
drainage in the backyard, resulting in a 1/4 to 1/2 inch crack
in the
basement garage just inside the garage door. It's obviously the
retaining wall that is moving, even though the crack is in the
foundation wall inside the garage just inside the door. The
crack is
diagonal running from outside the door to a low point inside the
garage.
Anyway, what would be the best method to fix this kind of crack?
ANy
suggestions would be greatly appreciated.
Thanks,
David