My tranny or tcase is making this knocking sound when i accelerate. the sound is coming from underneath. and when i let off the gas the sound goes away. the knocking sound was only heard in 5th gear. and slowly it started that knocking sound in 4th 3rd and 2nd sometimes i hear it in first. That sound only occurs when i accelerate.so far I checked the oil level and both tranny and tcase have the right amount and my u joints are still good. Im trying to find out if my tranny is bad or my dual cases are bad. Thanks for taking your time to read my post