ok im about to change the gear oil in my tranny 88" r154 what gear oil is best? i have about 185000 and i dont know when the last time it was changed because i just bought the car. i am also changin the rear end gear oil...again i dont know when the last change was on it too...soo should i just top it off and leave it alone or change it? if i should change it what should i use? i work at a valvoline vioc so i can get valvoline pretty cheap..but im not tryin to get out cheap im tryin to do it right.so whats my best bet? what brand and weight? also i have lsd in my supra and i have lubegaurd lsd additve at work i can use but agaqin i dont know whats recomoened so j dub im callin on u help me out oil man!! thanks