a borked center diff lock....a day before leaving for the Challenge.
I was supposed to put the car on the dyno Wednesday, but I need the ability to lock the front and back together to prevent power from being sent in all different directions. By locking the diff, I can drop the drive shaft and tune on a 2wd dyno. Instead, I found that the lock rod moves in funky directions that it shouldn't. I think the associated shift fork is bent or dislodged.
The GTX tranny has the ability to lock the center diff to equalize power sent to the front and back axles allowing the respective differentials to share the load from side to side. By locking the center diff, I can drop the drive shaft and tune the car on a 2wd dyno.
Fortunately, it's locked in such a place that the car still retains full 4wd capability, but through 3 open differentials and drives fine. I think I'll still be able to compete, though the transmission will have to come apart post-Challenge.