have transmission trouble in 2001 buick lesabre. bought car new. has 56000 miles on it.only drive about4000 miles per yr. since now age 73.
Here is the problem. If I drive car for 30 minutes , it shifts ok. After about 30 minutes of driving, the shifts from 1st to 2nd, and 2nd to 3rd hit hard, like a thump noise. There is no grinding of the gears in shifting. There is no delay in shifts.Here is the weird part . If I then stop the car and let it rest for half an hour and then restart and drive, it shifts smoothly again. When it starts to hit hard between shifts, there is a whinning sound that accompanies this. The manuel that came with the car says to change transmission fluid and filter at 50000 miles if its been all city driving. Its 90 percent city driving. Have not changed fluid or filter, as it may not be the problem. if I bring car to a transmission shop , they will probably tell me to rebuild transmission. I wont do that since car is 12 years old. If its a small repair under 200 dollars, id fix it. Any transmission experts out there who might know what the problem could be?
thanks much if you could reply to this question.