OK, here goes my first post!

Have 1990 Montero LWB, 3L V6.
I found two posts covering similar issues but on different makes so I want to check with the powers before I go tearing into the TC.
When I am driving, and ONLY when I accelerate AND go over any bump I hear a vibration and hear a grinding noise at the low point in the shock depression. This noise is only when I am accelerating and only when I go over any bumps and is at the lowest point in the spring load.
On other brands they say it the 4WD TC trying to engage at the lowest point in the dip of the shocks. I am beginning to think this is the case with my unit but I Do not know where to start.
Does anybody have any experience with this?
The Drive lines are all tight, the shocks are new, the Monti only has 115K and has been in 4WD only a hand full of times in its life (My Grandma bought it new).

I'll bet most anything you want that it is not the TC, UNLESS the bellhousing bolts are loose, which I'd check first thing. I'd jack it up under the lower a arm and use a big pry bar to check the ball joints and tie rod ends AND the idler arm on the pside. Also have a helper turn the steering wheel left/right/left/right to check the steering joints, including the latter two in the list above. Also check the wheel bearings for tightness by grasping the wheel at top and bottom and vigorously wobbling the wheel. Also try to shake the outer end of the cv shaft in the hub, checking the needle bearings there. Inspect the shock end bushings. Also put a jack on the oil pan and inspect the motor mounts for breakage and deterioration. The sound you hear may be the fan hitting the shroud...

Also inspect the ujoints in the rear driveshaft. Any slop means new uhoints...

Check the transmission mount also.

It was the motor mounts..... Thank you so much.

I guess that if I name enough stuff, one of them has to be right...

Welcome to the forum <img src="/forums/images/graemlins/cheers.gif" alt="" />
.
115k, it's not even broken in...
Have you replaced Harmonic Balancer Bolt with new revised bolt and torque?
That's the first thing to check when you get a 3.0.
The rest of the truck is pretty bullit proof, 'cepten' some rubber part age degradation as you just experienced,,,but you''l find if your in a roadsalt and low ozone area most of your rubber bushing will even still be good.

Thank you again, my tendency to laser in on one thing would have cost me a buttload this time. <img src="/forums/images/graemlins/butwiggle.gif" alt="" />

The HB bolt Seems to have been replaced with a non stock bolt yet it looks different then the one shown on a post I was looking at last night. Before I posted questions on that post I was going to make sure of what bolt I had in. I have the TB belt kit with the tens and was going to just order a bolt when I replaced the TB. The bolt looks longer then others I have seen that were stock. Ill look that post up again and just order the new bolt. I have to get the tork spec off of it.

Btw, you know the factory service manual is available for download online right? It's for the 89 but the tb r&r procedure is the same.

It's at Mitsubishi links dot com. <img src="/forums/images/graemlins/kewl.gif" alt="" />

The 1st bolt was long and fat,,,
the 2nd "improved" bolt was long with a bolt head and a skinney neck( not available/superceeded),,,
The 3rd is a short (no neck)bolt.
The improvements was possibly a harder grade bolt(although there is no indication of this) but most likely is just the increased torque.
I'd replace your bolt and washer on next TB job. They are too cheap not to replace and be sure.