Transmission oil change

I have a 2013 Jeep Grand Cherokee with 30,000 miles. I change the engine oil twice a year and was wondering if it would be a total waste of time and money to change all transmission oil at this mileage, as I wish to keep the vehicle in best possible condition.

Also, could you give me any information on friction modifiers for future reference? Ray Bradford

You do not mention which engine you have in your Jeep, so I am making the assumption it is the more common 3.0 unit. The recommended change interval for the diff and transfer box oils is 50,000 miles, while the automatic transmission oil interval is 62,500 miles. Gearbox and transmission oil on four-wheel drive vehicles does take a hammering, so changing them at 30,000 miles would prolong the life of the components.

Regarding friction modifiers, I am assuming that you are considering this for your Jeep. There are such a wide range of friction modifiers that it would be impossible to list all of the options here. In general, modern vehicles have been designed to use specific oils and modern synthetic oils do a very good job, so most manufacturers advise that friction modifiers should not be used in their vehicles – this is especially true if a limited slip differential is fitted.