NEED HELP 4WD issue

[egger46]

I have an 05 Isuzu Ascender with 200,000+ miles on it that I recently bought used. I have a lot of noise in the front end while at all speeds. I wanted to test the 4HI setting the other night while in the drive thru and I engaged it and attempted to turn out of the lane and the entire truck came to a stop. I heard a loud clunk. I immediately backed a little and disengaged the 4WD. Nothing has flown out during regular driving. My question is, could this be a CV axle issue? They do not make the familiar clicking when cornering like a bad CV would.

 

[christo829]

Ugh... My bet is that it's the splined disconnect. Do you have any idea how well the previous owner maintained it? The disconnect grease could be shot/gone.
Did you check front differential fluid? The noise could have been coming from that, especially if it was a loud gear whine. If you're lucky, the disconnect could just be really stiff, not broken, but you'll have to get in to it to check the grease.

What sort of noises were you hearing? Also, how tight of a turn out were you attempting? Tight turns in 4wd will bind and crow hop.

Before you try anything else, check the front and rear differential fluid levels and the transfer case. Make sure you can get the fill plugs loose before popping the
drains. Take note of what the lubricant looks like.

Good Luck-

Chris

 

[egger46]

"What sort of noises were you hearing? Also, how tight of a turn out were you attempting? Tight turns in 4wd will bind and crow hop."

@christo829 The noise is a harmonic grinding with a sort of clicking in it. I am guessing maybe that is the wheel hub. The turn from the drive thru was fairly tight, not a full stop turn though. The good news is that the vehicle is not making any new noises after the drive through lock up. It is a little cold here now and I haven't had a chance to get under and look at it yet. I plan on checking the Diff fluid and give it a general inspection.

 

[webdawg]

The disconnect sound would come from the passenger side of the car.