[1976gmc20]

Okay, since I am still sort of lost in the last millennium, I am curious to know how the front axles work in the 2000++ model year 4wd pickups:

Do they still have some sort of "central axle disconnect" like the GMT400 4wd IFS had, or do they just forget that altogether and let everything turn all the time ????


My 1989 K1500 4wd didn't work when I got it, and instead of replacing the problematic "donkey dick" actuator, I just unplugged and shimmed it with a short piece of plastic pipe so "the hubs are locked in" all the time. It's been that way now since I bought it about seven years ago. I just shift 2hi/4hi/4lo as necessary.

My concern - besides these actuators failing when you need them the most - is that with the axle on one side (right) disconnected, the left axle will be spinning the spider gears at a dizzy rate because the carrier and driveshaft aren't turning. How can that be good for the differential? You aren't even supposed to run different size tires on a drive axle, and not supposed to spin one wheel at high speeds if you get stuck. And of course if you had the old solid 4wd front axles you really weren't supposed to drive with one hub locked and the other unlocked. The latter is in effect what is happening with the IFS axle disconnect systems.