No idea how to search for this...but I'm sure someone here has had this problem before.

My '91 T4R just got it's 4.88's with factory e-locker installed. A friend who I trust (used to build drag cars, and has set up numerous r&p) installed my Yukon gears. Modified my housing, got everything installed. I'm going through the break-in period now, and I'm paranoid and panicking at every little noise.

For now, there is a vibration noise that only occurs when I'm every so light on the throttle. Not an acceleration, but not a coast. Just that small space where you are just giving gas to stay at speed. No other time do I hear it. Coupled with this, I can hear a click at < 2 mph like rolling back out of my drive way, or coasting up the driveway with no load on the driveline.

Someone suggested the u-joints, and I did a very quick check, and the back joint felt ok. I will be further inspecting it. And I did have a moment of "OH ˟˟˟˟˟!" a while back; I started the truck during the time it was on jack stands just to keep everything up, left it in neutral, and let out on the clutch. The driveshaft, which was still bolted to the t-case, started to flop around. I know that I may have done some damage, but not sure what. More info to help determine what is going on, the front diff is out of the truck, and that driveshaft is just hanging loose (I've marked and removed the smaller piece).

I'm almost halfway through the break-in, and don't want to be screwing anything up, I don't have the funds to replace anything, and I'm already registered for the Appalachian Toyota Roundup in 5 weeks.