At approximately 45-47 mph, (right after it shifts to overdrive) my car has a slight surge or jerk, sometimes its slight, and sometimes its more than slight, but not violent. About 8 thousand miles ago, my transmission was rebuilt, it is still under warranty. I took my car to my local dealer and the tech said that if felt like "TCC chug". I'm not so sure thats it. If you accelerate you don't feel it, if you decellerate, you don't feel it. You have to keep the peddle pressure constant. To me it feels like a miss, but my timing is on. Also, you can kind of hear the problem in other gears. If you are in say 2nd gear, and you keep the peddle pressure constant, you don't feel any surges, but you can hear what sounds to me like a miss in the exhaust. Any ideas as to what this might be??? Thanks for your help. Matt

 

I have that same thing in my Monte SS, just after lockup. It's at about 1600 rpm. I have redone and rechecked everything ten times over with no luck. It even did it after I changed my rear axle ratio. I just work around it since I have good mileage, power, and driveability otherwise.

 

Yeah I know, the car runs pretty good otherwise, its just annoying as hell!