I bought my 2007 TLS 6MT from a Honda dealership a couple of years ago with 75,000 on it. The dealership changed the fluid before I bought it. I would have assumed they used the Honda stuff. I had very occasional 3rd gear issues so when I went to change the fluid at 95,000 I went with the Honda Improved Formula stuff it was a lot easier to get ahold of the the GM Syncromesh FM. I got about 3000 miles of ok shifting on the Honda stuff than it all went downhill. It turned into 3rd gear notchy shifts on every shift as well as 1st gear issues and even reverse issues. I thought the transmission was done. I figured I didn't tightened the drain plug and all the fluid leaked out. I picked up the GM Synchromesh FM (Now AC Delco ) and changed out the honda stuff. I got 2+ quarts out and it was clean fluid. I don't think I need to repeat what has been said 100+ times on the forums that the GM FM made a night and day difference. It shifts better than it ever has. I figure the honda dealership must have known not to put the Honda fluid in and I essentially downgraded to the Honda when I changed it.


It is obvious that the Honda fluid works or people would complain from day one about Honda's 6MT. I have seen on the forums many posts about people with low mileage running it with no problems. Is anyone sticking with the Honda MTF at 75,000 + mileage with no problem?

My thoughts is the Honda stuff is a waste if you have 75,000+ miles and to stay away from it. Improved formula or not.

 

My '05 was switched out to the "newer" Honda fluid a couple of years ago (2009'ish around 60k miles maybe) and it improved the feel a bit, but not perfect. I don't have the 3rd gear issues, I have issues with 2nd and 6th refusing to engage (no grinding). Before they changed out my fluid I think I was fighting 2nd/6th several times per week. After they changed the fluid, it was maybe once a month and sometimes more often during winter.

About 2 months ago I finally swapped mine out for GM SMFM and it again is an improvement. I am very curious to see how it behaves as it gets colder out. Most shifts are much smoother with the GM juice, with 2nd/6th so far only being cranky when it has gotten below 40F.