I have a 95 monte carlo 3.1 with 170000 miles. After driving 200 miles today, my transmission started to act weird. I have noticed that sometimes 1st to 2nd would shift hard but not that hard. Today when I was at a drive thru I noticed a weird whine/grinding sort of noise that seemed to come from the left front wheel. This sound could be heard in any gear and park and became louder when you rev the engine. As I got into town the transmission really started to act up and not engaging any gears but first and when it would go to shift the rpm's would spike like it was in neutral. Then a couple more minutes after that, the transmission went out. No matter what gear I put the car in, it would act like it was in neutral. Now if I let my car sit for a little while and let it cool down a little bit. The transmission works great but still has the growling sound about 2 minutes after I start it up and then 2 minutes later the transmission will go back out. What is causing this problem? What could be come temp fixes I could do till I could get it fixed? And how hard hard is it to replace the transmission?