1995 ford explorer vibrtion/shaking

my truck is vibrating and shaking when you go over 30. but occasionally stops. i replaced the whole rear end, rear shocks, rear brakes, rear drive shaft U- joints, rebalanced the rear tires( they needed that). at least that fixed the noise (grinding) from the rear end is gone but it is still vibrating… Over $700 in it this week. at least i did the repairs myself and saved a bunch of money. But i am now stumped… I dont know it if is front end issues, transfer case issues, transmission issues…
anyone have suggestions on where to start next… i need my truck for work and cant afford to replace it… but it is sinking me in repairs too… HELP PLEASE

Check engine light on? If so get the codes read.

I assume you’ve done the common sense stuff to isolate the problem. Different gears. Try it in 4x4 mode and 2 x 4 mode, etc.

Did you replace the rear differential? A worn out one can cause these symptoms. Often a problem in what is called (I think) the differential “3rd member”. Maybe somebody more knowledgeable than I here knows what goes wrong w/it. But this happened to me in a 60’s Ford one time. Severe shacking at speeds above 20-30 mph. It came on all of a sudden. One day ok, the next day shaking. Repairing the differential fixed it straight away.

The next place I’d look is for any sign of damage to the rear drive shaft. Any knicks, bending? If it isn’t in balance, shaking is a symptom.

Beyond that, I’m always suspicious in 4x4’s of all of the driveline U-joints. Be sure those are greased & tight. Replace any loose ones.

Axel bearings could be a cause too, either just going bad and getting loose, or improperly adjusted.

havent tried it in 4wd. afraid i might make it worse. i replaced the complete rear end matching up 3.73 gear ratio and believe either 8.8 or 8.1 pinion gear…both rear u- joints, both shocks…

i am going to regrease the new u joints and replace the fronts. as a just in case after i drop that drive shaft and test drive it to see if the symptom is front there…

any other suggestions or ideas… shoot them my way

I would balance the front tires too…Then, put the entire vehicle up on blocks and see what’s shaking!