This is a fairly common problem. I guess we must be a world full of ham-fisted rally drivers.

At 08:40 PM 9/24/05 -0400, Gregory Brown wrote:
"My fix for the threads that are broken off of the shift lever is drill and tap the shank and Loctite a 5/16-18 set screw in it."

That's a nice trick. If you can find a long hardened steel set screw it should be stronger than the original part. Incidentally, it is the wrong thread pitch. Original thread here is 5/16-24-UNF.

The first time I had to deal with it I was still on a shoe string budget. I ground the sides down with a hand grinder to get back to the original stud size, then cut a new thread on it with a hand die, leaving the lever a little shorter.

More recently I had one where someone had welded a threaded stud on top, but that was a bit of a mess. I was never sure if there was enough material there to drill and tap, but it looks okay. Let me know if it ever breaks below the stud.

Here's one I finally had to do myself, September 21, 2008. By sheer coincidence it broke as I was approaching my brother's home with just a couple miles to go. He happens to have a lathe in his workshop. It was not a big deal to pull out the loose center carpet section from my tunnel and remove the rubber boot and snap ring to extract the hand lever. Incidentally, this is the third time I have broken one of these things in nearly a quarter million miles.

We put it in a 4-jaw chuck in the lathe, faced off the broken end, drilled and tapped it with 5/16-24-UNF thread. We found a hardened steel machine screw with full thread at least 1-1/2-inch long, cut the head off, and installed it with a bit of thread lock adhesive. This is by far stronger than the original mild steel part, so I expect it will never be broken again. Total repair time including reassembly, about a half hour.