Ok, i have a 2002 F150 Lariat, extended cab, 79,xxxx miles. I bought it used with 18,000 miles. To my knowledge, the gear oil has never been changed. I suppose i should get off my lazy duff and change it. Was debating using Royal Purple and at the same time doing my oil change. Anyone have any comments, for or against using Royal Purple?

 

Would using a synthetic have any negative effects on the LS clutches, as long as the proper amount of friction modifier is added?

 

royal purple is good stuff i use it in the rear of my truck