Filthy there was not much play. crazy thought here... could my torque converter make this sound a few months ago the bolts had backed out enough that it would rattle i have since re-torqued the bolts but could it have affected something?

 

Ok..not much play. I'm presupposing the U joints didn't have play in them either?

Let's try and duplicate the cause of this illness: With the vehicle on somewhat level ground, chock both front tires front and back tightly - you don't want the vehicle to move. Jack up the rear end and put jack stands, blocks of wood or something equivalent under the axle tube springs. Fire her up, put her in gear and listen for your "rooomph rooomph" sound. Be careful! You might need a helper (someone you trust haha) to keep the RPMs up - or adjust the idle speed up to 1500 - 2K RPM or 30 (or so) MPH.

Watch/listen from the rear tires, third member, driveshaft and on up to the trans. Have your helper apply the brakes when you tell him/her and listen/watch the rear tires for any wobble or different sounds. Do the same when you're moving up the drivetrain. If you don't have a helper to apply the brakes you could get in and do it...listen carefully for your sound(s).

If the torque converter wasn't seated when you re-torqued the bolts I think you would know it. Wouldn't hurt to recheck it anyway while you're underneath...with the engine off, of course.

 

this was actually what i was gonna try next, glad to see you were thinking it too. I saw somewhere that dry axle bearings may cause this noise...however i don't feel my axle bearings are dry as the gear lube is full and where the bearings are there is no extra heat.

 

Hahaha...great minds often walk the same path. Actually, I was suspecting a broke axle/outer axle berrins or carrier berrins when you said the pinion yoke just turns. But shot carrier berrins/races would make a whining noise if they were bad. Bad outside axle berrins/races would be growling. A broke axle would make a rythmic thump or "rooomph" but you'd notice that when the rear tire would pass you on the road....or have a nasty camber.

 

gonna say bad driver side outer axle bearing... as soon as the truck was put in gear in the air the noise began, however on the ground it only does it at roughly 20mph... faster and slower have no noise and only on deceleration. oh and i do have a few honda friends that want the back to camber out a little.

 

Glad you found the problem...centripetal forces under load/no-load conditions are not linear, hence the noise upon deceleration.

Ha ha! I'll never understand that. Looks like crap...along with lowriders and those "bouncy bouncy" vehicles.