i have a 04 6MT Ok so about 5 or 6k miles ago i put Redline tranny fluid in my transmission and lately i have been having trouble with the synchros like many people have when they run redline because it is not compatable and it shows up in cooler temps, well it has been just making a grinding sometimes while shifting and not let it go into gear with the clutch fully depressed.

well i planned to change it to Amsoil but just havent done it yet, well tonight i ran a S2k from a dig and i only launched it from maybe 1500 not hard at all (why should i its a S2k) and i got some wheel hope and then all the sudden i started to feel this hard vibration in the right side of my seat and hear a roaring noise, well i did everything i could think of to try diagnose and i figured out that it only makes the noise when it is
1: under a load and between 2-4k RPMs
2:and speed does not affect it i can do 80 as long as im not putting it under a hard load and i keep the RPMs low it does not make the noise

anyone have any ideas? first thing tomorow i am going to go to Nissan and buy OEM fluid and change it back but i have a feeling based on how bad the vibration is that that wont fix it.

could i have busted a tranny mount? since it happened during wheel hop that kinda makes me think i might have busted it

 

no one wanted to guess? well i think i found the problem i have a busted driveshaft carrier bearing.