On Oct 2, 10:39*pm, Steve Sr. wrote:
Hello,

I have an 1992 vintage MTB that uses a Shimano Rapidfire brake
lever/integrated shifter. The threads in the shifter that hold it to
the brake lever have become stripped and no longer hold. The shifter
is Deore DX group. I believe that the shift lever is model ST-M070 *or
071 for the front der.

It appears that this was a suspected issue as Shimano appears to have
put some type of heilicoil liner inside of the shifter to strengthen
the bite in the shifter. I believe a piece of this broke when the
original locktite failed to release upon removal of the attaching
bolt. *I suspect that this problem may have been a common one with
these shifters.

Repair Options?

Replace it (with a new model), they're cheap.