SO I have been working to get my 91 4wd pushbutton MT loyale up to 100% mechanically.... or as close as I can.

 

I get a grinding noise somewhere in the rear half when I get down a little more on the skinny fun pedal, or am going up a steeper hill. Pretty much anytime the rear end would "sink" due to acceleration or a hill.  the sound is the same weather im going 15 up a hill, or accelerating through 55mph. so it does not change with speed. It can happen over speed bumps, but is not struts due to it being a constant grind up hills. Now, the grinding sounds similar to really squeaky struts, but it is far to constant to be struts. Ive had it up on a lift and did a mild look over when i was changing the oil. but not digging to deep.

 

Possibly related to the issue but maybe not, If I am cursing at speed and give it a lot of gas quickly there is a clunk in the rear end. I thought it might just be the stowage compartment clanking. When I engage 4wd and punch the gas, the clunk goes away.

 

I'm really not sure what it could be, Just seeing if anyone has had experience with this problem. 

Your rear differential  front hanger bushings, and or the rear drive shaft support are probably on the way out.

great, I'll check those next and get them replaced!