Hello all, I've been searching the internet for days looking for a similar problem. Haven't found one so I'll try posting.

94 toyota pickup extra cab sr5
2001 5vze motor
fully rebuilt r150f, local transmisson shop all marlin crawler parts
brand new flywheel, clutch, and pressure plate
transfer case is untouched (thinking this is the problem)
brand new tom woods 1 piece drive shaft
brand new 8" yukon grizzly auto locking rear diff built by marlin crawler
brand new axles and wheel bearings
everything up front is fairly new OEM ball joins, bushings, tie rods, shocks, wheel bearings, axles.
OME HD lift kit with 3degree shims on the rear diff
brand new tires 33 10.5 r 15 i have rotated them with no changes
all mounts are solid, all bolts on the driveshaft are tight
transmission was 1/4 quart low, transfer case was correct, rear diff is good as well.

This started with I left a stop light in traffic, put it in first and normally engaged the clutch, there was an extremely loud bang and the truck lurched to the right side, had to turn the wheel to correct it. My first thought was the auto locker. I removed it and reinstalled my OEM one, while in there I added stronger axles and new wheels bearings. Going back to a stock differential did not change the sounds or vibrations.

From a stop there is a clicking noise, metal on metal, that is speed dependent. Putting it in 4wd hi or low does not change this. throwing it in neutral does not change it.
the noise fades away at 30mph, vibrations start to pick up, cannot drive more than 60mph BUT if I take it up to 70 everything is smooth sailing. I can feel the clicks and vibrations through both shift knobs. I cannot figure where exactly the noise is coming from, every shop is about 1.5 hours away. I'm stumped, I could have a junk yard transfer case shipped here and install it but I'm not even sure that's the problem, I have parked this thing for the time being, borrowing a friend's car till I can figure something out. Any help or questions would be appreciated.

Thank you!

 

Jack up the rear, spin the driveshaft by hand from underneath the truck and listen/feel for issues. Obviously use jack stands to support it while underneath. But if there’s broken pieces in the tcase I’d expect clicking or grinding no matter the speed.

Have you verified your upper rear control arms are in one piece? Had my second one break recently while I wait for parts to build new ones and with the pinion moving around it was unhappy. Doesn’t sound like that’s your issue but worth mentioning

 

Jacked up the truck and spun it by hand, nada. turned in on and put it in 1st, still nothing. Don't know how I didn't see or feel it earlier, lots of slop in the double joint up by the transfer case, driveshaft is less than a year old, going to pull it and see.

Thanks for the response! most likely wouldn't have checked again till later

edit: sent a small video to Tom Woods driveshafts, at some point they had defective grease fittings that wouldn't allow grease to flow to the center ball, will fix it free of charge. Phew, cheapest fix available.