My drives were white so I listened to the internet that it's overheating and on its way out. I replaced the drive oils and everything came out fine. No burned smell. Oil was clear. ( I replace about every 10 hrs). Yesterday I went out and my one drive was lagging going into forwards. Reverse and neutral was instant like the other side. But forwards would lag behind...fast forward through the day, we left the restaurant in the evening and boat wouldn't go into forwards at all. Again Reverse and neutral just fine....I think my question is, would this be signs of a worn clutch? Pulled it apart today to take a look and no signs of a metal or it even getting too hot. (Granite now both drives have calcium even down on the fin).

It's the shift shaft and cone clutch matting surfaces. The fix is replace both but some can band-aid by polishing the shaft

Cooling the drives is good but most important is using correct lube

What would one suggest. I was told some vr1. 74-140

Merc HP 90 is what I would use
Could also use Merc Synthetic but with a older drive it might start to leak out a seal. If it has fresh seals and not a B3 your good to go

Now using correct lube now will not fix current issue