Doug-

I think you may see more fatigue from the extra weight, not failure. They are not going to twist in half (torsional failure) unless there is an inclusion or stress riser and even then they are probably going to fracture longitudinally, not torsionally (i.e. splinter, vs twisted splines on an axle.)

Afterall, they are just spring steel and that will fatigue I think you will probably see some sagging over time. How much? Who knows. You may have to re-index a few times until they need to be replaced, but outright failure is probably not a concern.

Michael

This weekend I accidently reindexed my right t-bar. While dropping the front axle out swapping in my new 5.38 lsd axle assy. Maybe 3~4 splines, was cranked to the max, now I have extra threads showing.

Only Time i have seen T-bars get really screwed up was from PURE stupidity PURE to the Purest Form. Sadly it was a Chevy..... BUT it was twisted and broke from using a LONG wheels base on some rocks they should not have been on, got it hung up pretty bad and then his buddy was trying to yank him out BY THE TORSION BARS!!!! Back and Forth they went till it gave out. With a 6 pack and movie in front of you, why continue to wheel...