RGuy wrote:4PK611 is a traditional polyester v-belt and is installed to a specific 'tension'. It has very little stretch to it. I won't describe the tensioning process... it is well documented.
4PK592 is a ELAST (elastic / stretch type) v-belt and is streeeeetched to a specific 'length'. When installed at the correct length the tension should be correct and should never need retightening. Although it will not be easy, the best method is to install the new belt without moving the pulleys from their original positions.
4PK611 fits models manufactured 07/2003 and earlier.
4PK592 fits models manufactured 07/2003 and later. The pulley is a free wheeling type and is designed to reduce the shock to the belt on engine deceleration not to mention longer life. The pulley has a flat face. There should be a small triangle at the bottom front of the alternator cover to denote the new style belt and pulley.
Neal, what you say here is incorrect. The last 3 digits just indicate the length of the belt and not the feature "ELAST". You can buy a 4PK611 ELAST as well as a 4PK592 ELAST. Continental says that the 4PK611 (without Elast) is used in Hyundai cars and should not be used in oilheads. The ELAST version is to be used for oilheads only ... However many fellow riders (as well as myself) just use the 4PK611 without ELAST in their oilheads and never had any problems.
Sounds complicated, but the essence is that you can get these 2 belts in both the ELAST as well as the non-ELAST version and that has nothing to do with the last 3 digits.