Just changed my driver CV axle. Both of them are new now, the other one was in September. I noticed that sometimes, when in 5th or 2nd, once 1st, if I had my foot on the gas a little, nothing happened. If I pressed harder though, there was a rumbling, acceleration was slow, and after a few seconds the rumble would go away and the engine could accelerate like normal again. Also, if it rumbled in 5th, and I downshifted, no more rumbling. This sounds like an engine problem to me, but it also sounds like a transmission problem to me. Or it could be that my car is cussing old. Either way, I'd like to see if I can fix it. Let me know any thoughts. Thanks friends!