I need help, Ok i just got a new Manual 5 speed transmission with 40k miles on it. got it put into my car and shifts pretty good but alittle notchy. and ounce in a while 1st to 2nd grinds. So i decided I would try some RP 75w-90 and Lucas Transmission fix. But now i did that it shifts horrible, its like hitting a brick wall trying to shift into 1st at a dead stop. Can someone help me please?