Ok, so some of you may or may not have read my buildup thread. I decided to create another post since this is an outstanding issue and is preventing me from moving forward with my project and finally getting to play with my Jeep.

Listen to one of these clips closely, and you will hear what sounds like metal on metal not engaging properly, or something of that nature.

Short Version (sound is right at begining and right at the end):


Long Version:


The engine, tranny and clutch were all replaced 5 years (maybe 3000 miles since rebuild) by my uncle before me getting it a few months ago. So everything should work good right?? WRONG.

Now I have tried to eliminate everything from the equation, so here is what I have done so far:
-removed rear driveshaft and ran in FWD to eliminate the steep angle and stock shaft fromt he equation
-removed front to elminate the front shaft (even though it doesent turn when in 2wd)
-raised rear off the ground and spun the rear shaft by hand feeling for vibes, nothing found.
-spun tires while off the ground so that i could get more speed on the shaft, still no sound of vibe on the shaft.
-started jeep up while on the stands and ran it through the gears, still makes the noise with tires off the ground
-replaced tranny mounts
-replaced thoughout bearing
-replaced u-joints

when does it happen or make the noise:
-usually I notice it when i get up to speed and then push the clutch in to de-accelerate
-i dont notice it while i am on the gas at all
- i feel it mainly in the shifter more than i do in the body or seat

straight 6, T-5 tranny, dana 300, 1985 CJ-7 from Cali

Here is my buildup thread in case you want to see pictures or what not.
http://www.jeepsunlimited.com/forums/showthread.php?t=791480

So, let's here what you think it could be. I am completely out of ideas at this point and I think I have to yank the tranny and do a rebuild. But if i can avoid that, i will.

Thanks
Matt

Since you've had it up on stands, did you run it through the gears with the t-case in neutral? Mine makes a similar noise only when I de-cellerate(sp)and it's due to an extreme rear d-shaft angle coupled with an incorrectly set rear pinion angle. Mine never makes the noise in 4-lo while wheelin', only in 2-hi above 30 mph. Mines a trail only rig so it rarely gets above 20 mph so I don't worry about it. I've talked to several techs that I trust and get the same answer, the noise is caused by a torsional vibration due to the extreme angle of the rear d-shaft and an incorrect pinion angle. HTH.