Fix your broken speedometer cable & save $80

Digging this up for posterity...

I had this problem on my 1993 with 320K on the clock. Lots of people have been trying to reinforce the cracked tube with heat shrink. I read several accounts here and elsewhere that heat shrink failed to do the trick. While it may work for some and has a low barrier to entry, it will probably be a bit marginal and fails for many people. Epoxy is probably more robust if applied properly, but that's a big if. Preparation may require more patience than some people posses.

The problem is the inability to preload the interface with circumferential tension, AND the exceedingly low modulus of elasticity of polyolefins--it could be as low as 8 MPa!

I cut a strip of aluminum foil tape for HVAC into a 3/8" strip. It was probably 3-4" long, and I cleaned/degreased the plastic barrel and wrapped the tape tightly and neatly around the split end several times. The aluminum will not strech or allow the plastic to slip on the steel cable. Reinstalling it revealed a very positive and secure fit.

TLDR: Heat shrink is too stretchy. Aluminum tape works better.