Axle rattle when NOT in 4x4

[ShawnB]

Hello everyone!

I'm a complete noob, just bought my first Ford Ranger (2006 FX4), I got it while the jeep was getting fixed, fell so much in love with it, I sold the Jeep!!

Two new CV axils and a new set of hub on the front, and I have one small rattle left. When the car is in 2 wheel drive there is a rattling noice coming from under the car (while driving). When I engage the 4x4, the rattling goes away, only to slightly come back under load (mostly when I accelerate hard). The noise was there from before the CV/hub replacement, which both CV Axels installed solidly.

I'm not sure if this is normal or not, but when I go under the car, I can rotate (only about half a degree or so), the axel going from the transfer case to the front differential. Also when the front wheels are up, there is the same degree of play in the wheel (rotating the wheel left or right, there appears to be a small bit of play in the transfer case), but it's uniform, at any rotational position, I can move the wheel back and forth a half degree or so, without it effecting the input shaft).

The bushings on both sides of the connecting axil look good, and the axil does not move laterally in any direction (I can only rotate it a half degree, but solid in its axis of rotation).

So where is the rattle coming from? Is it inside the transfer case, or front diff? I imagine that since the noise mostly goes away, when I engage the 4x4, it has to be somewhere in the front wheel drive train?

Sorry if this is a duplicate topic, I did search for "axle rattle" and found nothing.

Any help would be greatly appreciated!

 

[SenorNoob]

Sounds like a stretched chain in the transfer case to me... But I only know of that problem from books. Never experienced it myself.