2006 gmc transfer case problems

[Blakeman350]

I have a 2006 GMC Sierra 1500 with the 4 button 4 wheel drive selector switch, when I push the 4 hi button the transfer case motor makes a grinding sound the the 4 auto light comes on. It will shift to 2wd and 4lo no problem but will not shift into 4 hi. I’ve replaced the actuator in the front dif, the encoder motor assembly on the transfer case and the button assembly in the dash and I’m running out of ideas so any in put would be great.

[Blakeman350]

Never mind, the new transfer case shift motor I just put in last week failed. I guess I’ll exchange it in the morning for a new one.