Hi BITOGERs. Wondering if anyone knows if it is okay to use Royal Purple Synyhetic gear oil in the PTU on my 17 Ford Explorer XLT? I found an unopened bottle in my oil stash and it's the right weight for the job, but it says it has friction modifiers in it already. I couldn't find anything either way regarding whether or not friction modifiers are okay for the PTU. I'm at 35,000 miles and heard that it's best to swap the gear oil in these early.