[Greyson]

I've got an 89 Jeep Cherokee Limited, 4.0 Liter, 4WD, Automatic Transmission. It was a nice vehicle until about 2 months ago. It started to shake pretty bad at speeds of 45mph or higher. I took it too a mechanic and he said the rear end was shot and wanted $1200 to replace it. That was a bit steep so I did it myself. I found a used but in great condition rear and spent 9 hours learning how to remove and re-install one. So I figure ok, that's done! Now I can get back on the road. Well, nope... It didn't fix a thing. I still have the exact same problem but at least can rule out anything in the rear end as the problem.

When I say shaking, I mean bad enough to where it moves the people in the passenger compartment. And the dash sounds like it's going to fall out at any moment. Does anyone have any idea what might be causing this?

I've searched and looked for a couple weeks now and I haven't found any real solutions. And I'm not about to go back to a mechanic who just wants to get in my pocket.

On a side note, I've had the Cherokee for about 4 years and from the start it's had an odd 'rubbing' noise coming from what sounds like the rear of the vehicle. The noise is speed dependant. The faster I go the faster the noise gets. Replacing the rear end didn't change that either. It still makes that noise. I don't know if there's any connection or not but I thought It was important enough to mention.

Recently (within a year or so) replaced parts:
Hubs & Shoes (rear)
Rotors & Pads (front)
Entire Rear-End Assembly
All 4 tires

Any and all help as soon as possible would be greatly appreciated.
Greyson