It's probably the speed sensors for the transmission.I had the same problem with my 1999. I suggest you pull the codes from the computer, You will need a OBD2 code scaner to do this.The codes are P0715 for the input shaft sensor & P0720 for the output sensor,it is suggested that you replace both sensor's at the same time. If you can't get your hands on a scaner and you have a Auto Zone parts house near you they will pull the codes for you for free.
Hyundai SP3 transmission fluid is used in a 2005 Hyundai Accent. This brand of transmission fluid is recommended by Hyundai.
transmission connections Hyundai Accent 2002
The transmission filter is located under the transmission on a 2002 Hyundai Sonata. it is under the transmission drain pan.
Hyundai Transmission Fluid HY SPIII. Use nothing else.
where is the transmission filter on a 2005 Hyundai Santa-fe
Hyundai ATF only.
where is the external transmission filter located on a 2004 Hyundai elantra
How do i check the transmission fluid in a manual 99 Hyundai Accent?
2005 Hyundai accent needs what kind of transmission fluid?
The transmission on a 2002 Hyundai will have a drain bolt located underneath it. Loosen the bolt and drain the old fluid into a pan. Once done use Hyundai recommended transmission fluid and pour it in.
Where do you fill the transmission fluid on a 07 Hyundai elantra 5 speed
how to remove transmission on Santa Fe