Car is a 93 ex sedan, EH9 with as-far-as-i-know original d16z6 and automatic. The vin pulls up automatic, and the car appears entirely original in the engine.

basically, while I'm accelerating, either in drive or with the shifter moving it N -> 1 -> 2 -> 3 -> 4, I can watch the RPMs and depending on the throttle opening I can literally feel it shift

the weird thing is: after shifting into 4th, only when traveling over 50mph, the RPMs drop about 500 RPMs as if its shifting again.

is this normal? a sign my trans is going bad or something? I dont get it, I thought these were 4 speed automatics but it honestly seems to shifts into another gear after being in 4th

 

Basically, after shifting into 4th and driving down the road at 50mph, the tach will move from a constant 2500 to 2000 and stay there at 50mph.

 

The lockup torque converter will feel like another shift.

 

Hows that work?

 

IDK how it works, but i know what it is/does. Basically, when low loads are present at higher speeds (ie 4th gear), the torque converter locks which essentially makes it a manual transmission - the wheels and engine are moving together 100% now. It takes away the (what i like to call) springiness of accelerating or cruising with an automatic, it feels like the revs wind up and THEN the car gets moving. The purpose of the lockup torque converter is so you can get better mileage on cruises and makes it feel more crisp and solid when slowly picking up speed, the way cars were DESIGNED to be.