2001 Santa Fe Gear problem
 

I have a 2001 Hyundai Santa Fe. It has worked great but it had this problem since the day I got it. The problem is that whenever I want to shift my gear into Parking, I need to have my hand brake(emergency brake) up, otherwise, the car will slightly move foward or backwards, and the gear would be locked in Parking. I then would need someone to push the car opposite to how it shifted, while I am inside trying to shift the gear into reverse or any other. It's a rather rare problem and I cant seem to find the solution with the mechanics i have discussed it with. Please enlight me on what could be the solution for this problem.
Thank you in advance.

Always use the parking brake when parked. It's not just an emergency brake.

I know that, I always do it. I'm refering that if I want to shift gear from or to Parking from any other gear and I dont have my parking brake on, it will lock.

I think I understand. In [P]ark, the parking pawl inside the transmission engages so tightly that you find it difficult to disengage it. Are you parking on a slope in a fashion that the weight of the vehicle shifts when you engage park and lift your foot off the brake? Are the symptoms just as bad if parking on level ground? There will be a natural tendency on a slope to experience this situation, but you should still be able to disengage Park with a reasonable effort. From what you describe, I think the problem is internal. I suspect most mechanics probably feel nobody is going to pay for a tranny rebuild for a problem described as a nusance, so they blow it off as a concern. Have you discussed this a mechanic that speciallizes in transmissions? If not, I would try that approach.

It's how you say, in slopes i would expect it to be hard, but on level ground is that it happens. I have never allowed it to happen on a slope, i would think it would be impossible to unlock it there.