How often do I need to change the oil in the limited slip??

 

It should be ok until it gets contaminated by water or something. I believe the diff fluid ford uses is synthetic and supposed to last the life of the truck assuming it isn't corrupted. I'm guessing I'll have to replace the clutches in my LS after 50K or so, and I'll change the fluid then. I think changing it every 50K is ok with synthetic fluids. On my other truck I do all the fluids annually regardless of milage.

Mitch

 

I do my L/S rear-end and manual transmission every 30,000 miles. I use Royal Purple. If you do change the rear-end fluid remember that with limited slip to add the friction modifier to the oil, regardless of what the brand may tell you.

Royal Purple states you "don't" need to because it is in their oil. However if you ask Mike from superchips who does a lot or research and develping of after market parts for F150 he will tell you the same thing.

 

thanks guys!