The mad science behind keeping axleshafts alive is a lot like the mad science behind keeping a supermodel girlfriend happy: you don't really care why it works as long as it does. However, it only took a few minutes for us to make flight arrangements out of our Los Angeles hell hole to the Pacific Northwest when Mac McMillan from Randy's Ring & Pinion invited us up for the day to break a bunch of different axleshafts on Longfield Super Axles' axle-snapping jig. The machine measures the amount of twist the shaft can take as well as ultimate break strength. So just how much stronger was a chromoly shaft than a standard one? How much of a difference did through-hardening and cryogenic freezing make? And was it worth the added expense? We wanted to know just that. Plus, watching axles snap from behind the safety of bulletproof Lexan is almost as cool as judging a nude dance contest between Jessica Alba and Carmen Electra ... we said almost as cool. Anyway, we broke up to three samples of each shaft for consistency and tossed the highest and lowest results, here's what we found out.
| Dana 44 outer stub | Twist (degrees) | Ultimate break strength(lb-ft) |
| Stock | 35 | 3,500 |
4340 chromoly
through-hardened | 35 | 4,500 |
4340 dual heat-treat
(experimental) | 40 | 5,000 |
| Dana 60 35-spline outer stub | Twist (degrees) | Ultimate break strength (lb-ft) |
| Stock | 30 | 8,100 |
4340 chromoly
through-hardened | 130 | 10,500 |
| 4340 chromoly dual heat-treat (experimental) | 50 | 7,500 |
4340 chromoly
through-hardened
and cryogenically frozen | 125 | 12,500 |