synthetic tranny fluid

stangGT97

New Member
Dec 22, 2004
1,299
1
0
Boston area, MA
just wondering guys, I recently put synthetic transmission fluid in my T-45 and now 2nd gear grinds all the time. It never used to do that with conventional fluid, so I was thinking that maybe synthetic is too slippery for the syncros in the T-45? Do I need friction modifier or something, because this grinding is getting really annoying. Thanks for any help!