Changing my tranny fluid makes a notable difference in how my synchros respond to input. You change yours every 120k miles...I'll keep wasting my time and money every 15k.

 

My opinion is in my sig.

 

FYI, service interval for manual transmission actually varies by year, according to the service manual:
2000: 90k miles
2001-2003: 120k miles
2004-2005: 60k miles
2006: by maintenance minder indicator

Regardless, having had many manual transmission cars over the years, I find that after as little as 6 months (it does vary a bit by car, car age, and by oil brand) I can tell the difference in shift quality between old oil and new oil of the same exact brand & type. I also assume that the poorer shifting quality is also somewhat increasing the wear on the wearable parts. For both quality and longevity reasons then, I change the fluid once or twice a year.

If you don't want to do that, that's fine for you. You probably also don't believe in synthetic oils either, and, will probably wait the full 100k+ miles to change your spark plugs as well. You don't need a custom alignment or a precision valve adjustment either. Don't play with tire pressure. No CAI, not even an aftermarket air filter. Stock everything, just the way honda made it, is fine for you. That is fine. To each their own.

 

its worth it to me, and not everyones has is the same, some burn oil faster, some drive agressively,

at 3500-4k my engine oil is a lot thinner,

my differential fluid was black at 22k

my tranny fluid at 22k was decent, just a little burnt, but for the price i think 20-25k for the tranny is fine.


YOUR A BITTER PERSON!

 

Sorry I didn't clarify - by look I meant analyze

 

For the sake of $30 I get the diff and gearbox oil done wen I have it serviced. Why should they get worse treatment than the engine

 

For the record I have changed my transmission oil 3 times in the last 7000 miles. No, I'm not joking. I will take the blame if the OP's head explodes after reading this.

 

HAHAHAHAHA... are you serious??? have you even been to Japan??? It gets freaking Hot!! I grew up in Miami Florida and I can say that Japan in the Summer has even more humidity then Miami!!! you walk outside and immediately your drenched in sweat and moisture! LOL.......

 

Well, in my case KAAZ recommends changing the differential oil at 3,000 mile intervals, and (especially in colder weather) the LSD complains if I extend that interval. My (AP1) transmission also shifts better with a fresh load of MTF, so I intent do try changing it at the same interval I change the diff oil. If I don't feel improved shifting after the change I'll extend the interval. I do oil analysis only to insure that my intervals are not too long, and base the actual change intervals on other factors. I have found that most cars accumulate more varnish if I extend the oil change interval beyond 3,000 miles, and I like the new look inside the motor so much that the expense of the changes doesn't matter.

I change fluids at intervals that produce the end result *I* prefer, so it is hardly a matter of blind faith. Even though the goals are different, my approach makes just as much sense as ringing every last mile out of one's lubricants. I get my money's worth, and I'm sure the guys who use extended change intervals can say the same. For me, pulling the cam cover off and seeing shiney, new looking parts, is worth whatever it costs.

 

Hmm. According to this page http://www.worldweather.org/068/c00183f.htm#climate, Tokyo's hottest month is August with a mean daily high temp of only 87.4 F.

Humidity might be bad for people, but that doesn't have much effect on transmissions - they don't have evaporative cooling like we do.