gm makes two versions of their synchromesh tranny fluid, a regular version, and a friction modified version. You want the friction modified version. I guess it just has a better "healing effect". But it takes time (like a week or two) and it usually doesn't come cheap. The GM dealer wanted to charge me like 11.50 a fucking quart and i talked him down to 10
Well worth the cash though. Any GM dealer should have it. If you need to, search for it on honda tech for the part number