Transfer case issue in 4 low - 2004 GMC 2500

[Ekliptix]

I recently changed fluids in my 2004 GMC 2500HD. Trans, diffs, transfer case (Dex 3).
Today I was plowing in 4 low, and started to hear an odd noise from the transfer case.

- 2wd and 4 high, no issue.
- When switching into 4 low, put it in neutral, push 4 low button, light blinks then goes solid. Still no noise/issue.
- When changing from neutral to drive, a noise starts, like the gears in the transfer case are hunting to mesh together. Now, it won't actually go into 4 low. 4 high still works fine.

Any thoughts before I visit a trans shop?

[AndyL]

Heated shop, let it warm up/dry off try again. One of the pushbuttons is notorious for it...

The gay man cruiser I get stuck plowing with on occasion does it too - I just plow in 4hi. It's survived 8 seasons now...

[Ekliptix]

You're saying a common issue is related to the 4 low button, and moisture?

[firebane]

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You're saying a common issue is related to the 4 low button, and moisture?

The actuator motor on the transfer case are known to fail. It made need to be swapped.

https://www.youtube.com/watch?v=THgtXb-RI5o

[AndyL]

I can't remember the mechanics explanation - not the same as the old 1st gen s10 issue with the axle disconnect but yeah, let it warm up dry out and it goes back to normal.

[Ekliptix]

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The actuator motor on the transfer case are known to fail. It made need to be swapped.

https://www.youtube.com/watch?v=THgtXb-RI5o

Interesting, thank you. Since it can go into 4 high without issue, would that suggest the actuator motor is working fine?

[never]

Just curious why you're plowing in 4-low? Can't say I've ever had a reason to do that.