I guess this would be the right place for this topic. I just changed the factory Honda lube on my 07 6 cylinder 6 spd MT after 21k. Replaced with new formulated Honda trans oil. This is after having the 3rd gear symptoms as mentioned on other threads. Improvement was immediate. I went with the new type Honda Lube due to concerns over the impact of other brands on the warranty. I will post updates in future on status.

Good luck. Hopefully it will work for you. It didn't for me. It improved things greatly for a couple of months, then it went back to the way it was before. I appreciate the concern about the warranty. I had the same concerns. However, I doubt that any dealer can actually tell which fluid you have in the transmission. I also doubt Honda can legally hold you to using the Honda fluid. I understand there is legal precedent against such practices. As far as I can tell Honda provides no specifications for the fluid. They only say use "Honda Fluid". Of course, legal or not they can try and hold you to that and dare you to sue them were they to choose to not honor the warranty due to non Honda fluid.

The story about legal precedent is kind of interesting. I don't know that it's true but I recall reading about it (in a reputable magazine) about 1 - 2 years ago. Apparently Ferrari insisted owners only use "Ferrari oil" or their warranty was voided. It cost something like $1000/qt. and the cars took about 8 quarts. With labor, etc an oil change cost $10,000+. Some owner (probably an attorney) sued them and won. At least the Honda trans oil is a bargain in comparison.

So far the GM Synchromesh (friction modified) fluid has worked perfectly for me. I changed it 10-07 and my trans has been perfect ever since. However, more time and miles are needed to really know if it's a perfect cure. I'm still crossing my fingers.

Magnusson-Moss warranty act says manufacturer can't make you use any particular fluid unless the manufacturer provides it free of charge. But I think there is a limit to that of course - obviously you couldn't use water in the engine and then blame Honda for not giving you free oil. So I think it is balanced out with another part of the act that says modifications cannot void the warranty unless the modification is shown to have caused the failure in question. So if your tranny goes south from bad tranny fluid, then I would say you're on the hook.

Interesting note for people having problems, how long are you keeping the new fluid in there? For some reason I noticed that my tranny felt no different in the beginning, but got better in the 10-20K range. The disclaimer for this of course is that it could have been weather, driving styles, etc, and also it was NOT the new fluid (but the new one could be the same?)

Interesting note for people having problems, how long are you keeping the new fluid in there?

I put the new Honda fluid in 10-06 and left it in for about 1 year and approximately 10,000 miles. It was never a 100% cure for my 3rd gear glitch but probably was about an 80% improvement. Unfortunately the problem returned in full after about 2 - 3 months and stayed that way until I put the GM fluid in. I don't think more miles with the new fluid would have worked for me, but it seems that not everyone has exactly the same problem or severity and more miles might make a difference. I bought my car 10-05 and the problem was quite noticeable after about a month. I probably had the issue from the beginning but just wrote it off as not quite being used to the transmission. My 3rd gear problem was never all that serious. It mostly just annoyed the heck out of me!

I had my fluid swapped around 7k, its about a year later and im at 42k +/-. It did seem to help. The car never shifted great but never grinds either, so im going to complain too much as I know there are lot on here with grind issues. Lately I have been noticing its not shifting so great, just hard to actually get the shifter into the gear I want easily... but then again its 0 degrees outside right now..

In general I would rate the actual shift action poor compared to the 2 other hondas and toyota I owned. Wonder if its the "short throw" bit. My friends 06 civic shifts like butter compared to mine.

From what I can tell is that with even the new Honda MT Fluid, the problem may or may not return. It appears that one must be prepared to change the Honda fluid every 20k at most. If the problem reoccurs sooner will proably try the GM. Other than that, perhaps just a regular synthetic motor oil (Mobile One or Royal Purple). I did however, document this change of the trans oil. I hope that this isn't a sign of things to come, similar to the auto trans problems.

I really think the issue with many people's transmission problems are related to the syncho's. Mobil 1, Purple, even new Honda, etc are no doubt very good if not excellent lubricants. But I don't think they are the cure for the synchro's. More slippery is not always better. The synchro's need to grip. I think that's why the friction modified GM fluid works for some people.

I used to have a Cougar that shifted fine until the temp went below 20 degrees. At that point it got extremely stiff and difficult to get into any gear. I frequented a couple of pretty good forums (like this one) and there was a cure. Put synthetic (I used Mobil 1) in for it's superior lubrication. However, it was noted that you also had to add Ford "Additive Friction Modifier" (I still have 3/4 of a bottle) to maintain normal shifting qualities. Part C8AZ-19B546A ref#137219. It only required about 1 - 2 oz if I recall correctly. It worked perfectly for me. Cold shifting was greatly improved and my car shifted just as it did before. The bottle says it's for "limited slip differentials, to reduce hypoid gear noise levels". I wish I would have tried a little with my new Honda trans fluid when I found it wasn't working for me, but I was uncertain as to how much to use.

It seems that not everyones transmission problems are exactly the same, so synthetics may work for some, others may need the GM friction modified fluid to get the synchros to grip properly. My trans works perfectly now, but it's only been a couple of months and a few thousand miles for me. I did read in a Honda 2000 forum a couple of accounts of people who had the GM fluid (fm) in for a year with positive results.

im gonna try out the gm synchromesh fluid since the dealerships can't seem to find out what the problem with the car is.

also, i was talkin to a honda tech and he said the type of fluid to put in the car is indeed specified.

also, i was talkin to a honda tech and he said the type of fluid to put in the car is indeed specified.

It's specified as Honda MTF, which is a bunch of donkey crap...Acura told their dealers to use GM fluid in the cars if they kept coming back for warranty