Almost a grinding noise when switching from 4x4 to 2 wheel drive?

I have a 2000 S-10 ZR-2. It has 45k on it and I live in Denver. I went to the mountains and it was snowing so I switched it to 4 wheel drive. After going through the rough spots of the pass I switched it back to two wheel and as I started to slow down I noticed that it was making a what sounded to be a grinding noise but..... at any rate I switched it back to four wheel and then back again, and it goes away.

Again I'm not sure if it is grinding or if it's just not fully releasing out of four wheel.
Has anyone else had this problem or any ideas as to what it may be?

It is the push button at any speed four wheel drive, but my consern is the transfer case. I do not want to do any harm to it as I know what it cost to replace etc.

Any help on this matter will be very apr.
Rob G

The encoder motor on your transfer case is acting up.

Have it looked at by a mechanic.

I had a similar problem with my 4x4 even though it is a manual shift. When shifting from 4X4 to 2X4 the light indicating the front diff was engaged stayed on. No grinding noise but I never drove with it like that. Ended up the vacuum cut off valve for the vacuum actuator was sticking. Just a thought and something to consider.