Won't shift into 4H/4L in cold weather...

[bandicoot]

I've had this issue for the last 2 winters...and just haven't gotten around to trying to fix it. Snowmobile season is coming soon I need 4x4 on the mtn passes.

I noticed when its below 0C (32F) the transfer case will not shift into 4H on the fly or stopped. The 4H light does not come on and nothing happens. If it warms up or its in the summer it will shift on the fly every time.

Any ideas?

[wiyrs]

maybe a different weight of gear oil, if it gets that cold and syncros dont work very good since the oil is so thick

[bandicoot]

The transfer case still spins while in 2wd, so the gear oil is heating up. I don't think the gear oil is the culprit. Any other ideas?