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I have a spare differential, so I'm gonna beat on this one until it explodes. ...if it explodes. I'm curious to see how long it lasts. It'll probably last longer than I can stand living without AWD.
Initially, it makes sense that the ABS is simply confused, but I don't follow why the ABS would be triggering the rear because of a lockup in the front. I believe it's a four-channel system, so applying brake to the rear would have to be a deliberate action by the ABS. I suppose I can see why it might think more brake in the rear would be appropriate, but I don't believe ABS systems ever add more brake. If that were the case, under normal circumstances any one wheel experiencing a traction loss would cause the ABS to apply more brake to the other three wheels, slowing the car down more than the driver demands given the applied brake pressure. By applying more brake, it also risks further upsetting the balance of the car and possibly locking up the other wheels which are its only reference to vehicle speed. The appropriate response of the ABS upon sensing a locked up condition, is to unlock the locked wheel(s). In my case (doing a brake stand), this should cause the car to roll forward, which it does not do. I'm not sure how obvious that is to the ABS computer however.
Then again, the finer points of how ABS systems work isn't my specialty, and it probably varies anyway.
I'm hesitant to declare outright that the SVX has a traction control system because I can still think of other possibilities. Perhaps the transmission senses the very high wheel speed and relatively light load, and decides to shift to second gear (I thought I had the selector in first, but in retrospect I'm not sure I did.) The engine didn't rev higher than 4500 RPM. Further tests will entail holding the throttle open a bit longer to see if it shifts back to first or if the ABS decides it's time to roll again. I'll also have to try chocking the front wheels or tying off to avoid using the brakes. (Too bad these things don't have front parking brakes like the old ones do. Those were the most bestest parking brakes ever.)
Another possibility is that the LSD clutches need a bit of action before they start working. I know some cars have exotic viscous-coupled, torque-sensing fluid systems and such that only bind up after they've been slipping for a moment, but I recall that the SVX just has an ordinary limited-slip differential.
The feel, and especially the noise, is very similar to what I've experienced when climbing snowy hills near the threshold of traction. (That particular symptom disappeared when I hot-wired the transfer clutch to remain locked in a 4WD mode.) It definitely feels like the ABS is doing something, but I'm still puzzled about exactly what it's doing and why.
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