odd sound

i rebuilt the motor in my xj recently and drove it around for abit last week and was getting this really weird noise. it sounds like a 10 speed changing gears and none of the mechanics i know have any idea what could be making the sound. the sound only happens when i'm running 55+mph or when i let off the gas at any speed. i recently changed the tranny fluid and filter. i haven't touched the transfer case except to adjust the linkage some since it wasn't letting me out of 4 high.

before i rebuilt the motor due to a rod knock i didn't have this sound so maybe i did something wrong when i bolted the tranny back up but it drives fine.

10 speed changing gears? ... it only happens at 55+mph plus or deceleration. Maybe the TC chain is either slapping or slipping on the sprocket? It kinda looks like a beefy 10 speed chain and sprocket.

think i might have adjusted the tc linkage wrong or not enough? it never made the sound before

Have you checked the t/c fluid level?

you know oddly enough i haven't. everything else has all new fluids but that's the 1 item i haven't done anything with yet. good idea