I know by no means this is a Honda forum. But most Honda owners with high mileage, worn bearing transmissions commonly develop a syncro problem. It tends to grind in some gears.

99% of the time, if they put GM Syncromesh with Friction Modified, the grinding goes away. My question, has anyone of you used the AMSOIL product for the same reason, if so, did it alleviate the problem? The 04 in our fleet just developed a 5th gear crunch and waiting for a new transmission will take weeks!!! I need something that will get us by for a few weeks.

 

Someone on another forum tried the friction modifier and said it work on the NV5600. Don't remember if was on the TDR or cumminsforums.com

I'm running 6 qts of Amsoil MTF in mine and it works great.

MikeyB