This just started last week when we got a huge dump of snow and I needed to start using the 4x4. Used it all last winter and this never occured.

4x4 works fine, engages fine, disengages fine. I take my foot off gas, slam 'er into 4hi and drive per normal, the reverse for disengaging.

Latley when your in 4x4 (4hi) if you take your foot off the gas and coast you hear a squeeking under the truck. Squeeking goes away when you re-apply gas.

Squeeking stops all togeather once it has been in 4x4 for 1-2 minutes.

Tcase fluid level is good and fluid itsself was changed last year.

Any idea what this could be?

 

Is it constant squeaking or short squeaks? Front driveshaft may need rebuild, low diff fluid, or bad front pinion bearing could be the culprit.

 

Constant untill you re-apply gas.

Also, like i said it goes away compleatly after 1-2 minutes of 4x4 driving.

 

I had the EXACT same symptoms when my double u-joint centering ball dried out. Soon after it failed completely. Everything got all loud and vibrate-y. You can (sometimes) tell if it's that by spinning the shaft by hand when in 2wd (truck off) and listening for the squeak.

 

Sounds like something worn in the dual cardan joint.

 

I just went under the truck and spun it, no squeek.

 

Does the truck squeak at very low speeds in 4x4? Also does the squeak go away after you pull the shift lever into 2wd or after the 4x4 light actually shuts off?

 

+1 however many on the front drive shaft. Do yourself a favor and bring the shaft to a local drive shaft shop and let them rebuild it. If you want to confirm, just remove it and drive it.

 

No Squeek at very low speed, unless you take foot off gas and coast.

Squeek continues when lever pulled out of 4hi untill the 4WD light shuts off

 

Front drive shaft, but I guess you don't care to at least except it as a possibility.