Manual Transmission noise

Similar to another post but not quite the same with very much different results but the noise from his post sounds similar to mine..

93 Ford Ranger 4.0 M5OD-R1 Manual transmission 4x4

In all gears only rolling I have noise that sounds like loose change or ball bearings being spun around in a jar. This noise is present in any gear and primarily under 45-50 MPH. above that it goes away. Here is what I have tested

Clutch in or out does not matter I am fairly sure its not a clutch issue
In or out of gear does not matter, even if I lug 5th down as long as I am under 45-50mph
Jacked up truck and tested all brakes and wheel bearings nothing found there.
Nothing I can find testing rear end from under the truck.

Seems I can make it more prevalent by quickly getting off the gas and leaving it in gear but regardless it will do it..

Various times its like those coins or ball bearings in the jar all of a sudden catch for just a second and line up and stop but then right back to it.

The intensity of the sound is the same at 5 mph as it is at 35 mph and engine RPM, gear selection, clutch in out do not make it worse or better.

I cannot "feel" anything while it is happening. There is no grinding feeling, no stumbling, no power loss, no drag, nothing.

It has me stumped, I am usually really quick to find issues like this but I have no idea other than I think its in the tranny. Unfortunately I am not in a position to tear it down without kind of having a direction to go because I have to get it back together again quickly.

Any help you all can provide or insight into the issue. I search through 20 pages of manual tranny posts and didn't find but the one that was similar. Hopefully someone has experienced this and knows where to point me.

Thanks in Advance TRS
Rick

Drop t-case in neutral and run it up to speed in 4th gear and see if your noise is still there at 35 while you are sitting still.

It reads to me more like a rear end issue. If the noise doesn't show up with the power train spun up and the drive train sitting still it's in the rear. If it does show up, rip the trans out.

If that doesn't get you any closer get it on 4 jack stands and have someone drive it while you are underneath. That should help you get a bearing on where the noise is.

It could also be a noise in the T-Case, because the planetary cage spins with the transmission output shaft regardless of the T-case shifter position.

AllanD

Thanks guys I am hopeful to have it on stands this weekend. I do have an update to above troubleshooting though.. Although I said differently above I noticed last night it is more severe when in any gear but decelerating. Clutch in or out still no difference but coasting vs loading is different.

You are not going to believe this one..

ADSM thanks for the idea to start and and run it up. I put it on jackstands and had my son run it up a little and it was immediately apparent what the noise was and it was a cheap fix..

Center support bearing for the rear driveshaft was broken worn the hell out. Took about a half hour to get the part and another 45 minutes to drop the shaft and put it all back together.

Thanks all
Rick