1995 Probe 5-speed Lubricant

Hello new to this forum. I got this probe 5 months ago , it had a pre-existing problem Reverse/5th gear synchronizer was bad and so was the shifting fork,I got both replaced by a GM tranny tech, which is a buddy of mine. After installation I asked the ford dealership what tranny lube was recommended, they told me 75w90 gear lube. My question is this. Is that correct ? Is 75w90 the correct tranny lube ? Or is it like the other 1988 and newer ford trannys,they use Dextron Mercron. The reason why I ask is the tranny is stuck even in neutral it wants to go forward. I need help. :banghead:

GM syncro-mesh is the only way to go!!!!

GM syncro-mesh is the only way to go!!!!

Penzoil has the same thing but much cheaper in cost.