Whining noise followed by clunk

[Mattjero]

Over the past week when travelling around 50kmhr on sealed roads in straight line the car intermittently makes a super loud zzzzz/ whining noise coming somewhere deep under the dash, the noise slows down as the car slows and then when I stop is followed by a big clunk. I have been driving it in 2H and now trying in 4H. I have taken it three times to mechanic who couldn’t find the problem as it wasn’t making the noise and also to a transmission specialist with no problem found. I have had the steering looked at the diffs pulled apart but no error found. The car goes easily in and out of all Four driving modes and the diff lock seems to be working fine. I’m stumped for ideas and potential costs to repair. Any ideas ???

Thanks

[Drewan]

When I first got mine I had a similar noise appear at speed and shit bricks turned out to be the plastic cover under the wheel arch but sounder like it came from under the center of the dash

[Axiste]

Currently experienceing this on my NM

If you drive in 4H it wont do it.

Seems intermittant in 2H (though more often than not these days)

Just had a play with the Vacuum Solenoids that control it, and noticed a few times where the wife sat behind the wheel, had 2H selected and locked in, but felt the yellow dot solenoid click a few times for no reason, so looks like its faulty. Weirdly I did have them swapped around for a bit, and while my hour of driving on the weekend seemed to show it fixed.. my wife then proved me wrong...

[Billy500]

Had the same on my 2002 NM.
Replaced the two solinoids under the bonnet on driver side. Replaced the short length of vacuum hose in that area also. Havnt had a problem for the last 12 months. I had the winding when in two wheel drive and as I slowed down to a stop then the clunk noise.

[TimTams]

on my NJ if I turn the key off while moving in 2H, the solenoids let go and the mechanism tries to drop into 4H, resulting in the grinding and eventual clunk when stopped. so a failed solenoid or faulty wiring to the solenoids will cause this. As has been said, driving in 4H is a good band-aid fix since the mechanism will be already engaged. you'll have to look at the solenoids at some point if you don't want to stay in 4H

[Axiste]

Picked up a new solenoid from Ashdown-Ingram yesterday, cost me $59. Has a much better build quality look and feel to the originals. Prior to putting it in, was getting the grind 1 - 3 times per 20km trip. Since putting it in, have done some 200km's with no grind!

Took a bit to find one, 1 wrecker couldnt source one, 1 wrecker laughed at me. 2 Aftermarket wholesalers said there wasnt enough demand for anyone to make one so it would have to be genuine, and of course, the local Mitsu dealer wanted $225 for one...