My SUV occasionally makes a very loud grinding noise , esp. after hitting a bump. at any speed, 2whl drive or 4whl drive. does not matter.
Usually l slow down, downshift , and let up on the gas, and it will quit the noise?
So on and on each set of washboard bumps, or one big bump.
Someone on the internet said it was a clutch flywhell vacumn solinoid, costs about $80 and l did change that.
This is an automatic 4whl on the fly, shift.
The only other strange thing l have noticed is that my brakes occasionally go to the floor when it is grinding? Any suggestions?
the noise and vibrations or gear clanking sound did improve after changing the first solinoid and the noise occasionally does happen in 4wdHigh.

It is a broken transaxle

Did u change just one solenoid or both that r on the plate? Also, u did not mention if, when u changed the solenoid(s), it helped?

The freewheel solenoids r known to go bad a LOT on the Montero, however, it usually happens all the time in 2WD. as a matter of fact if u r in 4wD it wo not happen because the freewheel system defaults to 4WD in the event of a problem so being in 4WD would eliminate the grinding.

Things like this r tough to diagnose hands off, but I'd check the front wheel bearings for being loose to start. if you're not familiar with that sort of thing take it to the dealer. l do not recommend taking this vehicle to a non Mitsu shop as they tend to butcher them regularly.