Odd sounds from under the cab. Been chasing for months.

Hey guys I'm new to the forum as this is my first post as well lol so here goes. I got a 1995 tacoma standard cab 4x4 5 speed. The only aftermarket thing installed is added a leaf upgraded front struts and rear shocks. Besides that it's pretty stock. Oh and an upgraded clutch and flywheel. I've been hearing an odd noise from under the cab that sounds like a loose heat shield almost. But only when in gear and under a load or if I leave it in gear and let off the throttle. So basically when there's any pressure on the drivetrain. And only when I'm moving. I thought it may have been engine vibration under a load causing a heat shield to vibrate but upon examination and having someone mess with the throttle when I'm underneath in the garage everything is tight. And I cannot recreate the sound unless I'm driving. It is pretty loud and just like a higher pitch metal sound like something bouncing around so I thought maybe something stuck in the driveshaft however then it would make that noise even if I hit the clutch at speed. So the only thing I can think of is perhaps a bearing going out it my transfer case? Output? I understand it is a gear drive. Syst so it can't be a chain rattling. I changed the x case fluid and it looked pretty clean. So I'm honestly at a loss at the moment and don't feel like spending 100+ bucks at a dealer to diagnose only for them to give me wrong information. (I don't trust dealers) lol any advice would be appreciated. Thanks!

P.s. Forgot to mention it does it in every gear past 2nd and the speed of the rattle seems to match the speed of the Motor not the wheels. So in 3rd gear at 3k rpm sounds the same as 4th gear at 3k. Was making that noise well before I replaced clutch and flywheel. So can't be throw out or pilot bearings.

 

Actually our t-cases are chain-driven. The hi-lux models were gear-driven.

Could it be the fan coming into contact with the shroud?

 

Oh really? Well the shroud and fan are plastic the sound is metallic and coming from directly under the cab

 

Well, then, I'd check the front drive-shaft u-joint, and then the rear motor-mount (attached to the tranny/TC).

 

SOLVED ended up being bad U-Joints and bad CV join in the driveshaft. (double cardan drive shaft) only 1 place to get U joints in the US....