Hyundai Repair: Hyundai Transmission Problem, hyundai elantra, transmission problem

Question
Hello. I have a Hyundai Elantra GS 2.0 L Engine , 4 cyclinder automatic transmission. When i bought it from a little dealership i had to rebuild the transmission once because it was slipping really bad. Now, im having another issue. When i drive up a incline/hill at 55mph it'll down shift but when it downshifts it jerks my whole car and revs up to 3,000 rpms for a second and then goes back don to 2000rpm's. My dad says its normal for it to downshift but i do not belive its suppose to jerk my car violently. What would you suggest i look into?

Answer
You're both correct.  It is indeed normal for it to downshift, but it shouldn't violently jerk the car and the rpm's shouldn't flare.

The first thing to do is to check the transmission fluid level and, if your able, check for any stored diagnostic trouble codes in the engine and transmission control modules.  Any codes present may direct you toward the problem.  If the fluid is okay and there are no stored codes, I'd say to take it to the nearest dealer for diagnosis.  It's possible that by relearning the transmission adaptive values (which the dealer will be able to do), the harsh shift will go away.

Even so, the greatest likelihood is still that the transmission is in need of replacement of overhaul.  Even if the shifts smooth out after a relearn, the abnormalities may come back after a short period of time.