Hi taqir, Unfortunately, there is no such thing as a "life-time" oil fill for any transmission, no matter what the manufacturer says. Transmission fluid is no different from any other liquid lubricant, in the sense that it is a base oil to which several different types of additives are added to reduce friction, corrosion, and the formation of sludge. However, transmission fluid is not affected by oxidation as much engine oil is, but over time, the additives in transmission fluid will break down due to the effects of heat and contact with oxygen. Nevertheless, high ambient temperatures, the effects of towing, and engine overheating are very difficult to quantify, so manufacturers base their claims of a "lifetime" oil fill for their transmissions on the supposition that the car will never be used for towing trailers and/or boats, that the engine will never overheat, and that the car will not be used in areas where it gets very hot. But this is only one half of the story. The other half involves the fact that modern transmisions are several times more complex than they were just ten years ago, so the reason why manufacturers do not provide dipsticks to check fluid levels is to prevent unskilled persons form tampering with the fluid level on the one hand, and to prevent people from adding the wrong fluid to a transmission, on the other hand. Most modern transmissions will only work with fluids that have been specifically designed for that specific transmission, and while most transmission fluids are red in colour, the wrong formulation can destroy a transmission. So, from a marketing perspective, it sounds great when a manufacturer says that the fluid never needs replacing, but from a practical standpoint, the transmission fluid cannot last forever. An added problem is that the amount of fluid some transmissions need are never published, so if you take the bull by the horns, and decide to replace the fluid in your transmission yourself, you don't know how much fluid will fill the transmission. Too much fluid is as bad as too little, so if you are experiencing trouble with a transmission that has a "lifetime" fill, the only place that can replace the fluid is the dealer, since you will often find that the transmission fluid for your car is only available from the dealer. My advice would be not to deal with independent transmission shops when you have problem with a transmission on which you cannot check, and adjust the level of the fluid yourself. Independents do not have the equipment to even check the fluid level, much less the diagnostic software to check for electronic causes of shifting problems. If your vehicle is still covered by a warranty, hold the dealer to his responsibility to fix all and any problems that you might have with the transmission. Lastly, transmissions that have "lifetime" fills have no set fluid replacement intervals, but if you do a lot of towing, I would suggest you have the fluid replaced at the dealer at least once every two years. Towing raises the temperature of transmission fluid significantly, which causes the premature breakdown of the additives in the fluid. I hope this helps, but if you have further questions or concerns, let me know.