If that is the correct weight recommended by Honda then yes you can use synthetic in the place of conventional lube.
Most motorcyles have a liguid clutch which means they run in motor oil so when you change your motor oil you are changing your (gearbox) transmission oil and to check your (gearbox) transmission oil level you check the motor oil level.
Yes, and it is in your mannual.
SAE 10w30 Synthetic oil any major brand.
5w30 motor oil. It's your personal preference if you want to use standard, blended, or synthetic motor oil.
Go to your Honda dealership and get Honda Manual Transmission fluid or just buy some 10W40 and put that in there it will work either way. do not use synthetic motor oil! Go to your Honda dealership and get Honda Manual Transmission fluid or just buy some 10W40 and put that in there it will work either way. do not use synthetic motor oil!
SAE 10w-30 Synthetic Oil any major brand.
The 1997 Honda Civic gearbox has a fluid capacity of 4.8 quarts. You can check the gearbox fluid level with the gearbox dipstick.
what gearbox oil doe's a hondacivic 1.4 1999 use?
It is a combination of synthetic oil and conventional oil.
No, you can even mix synthetic with conventional oil. It will do no harm at all.
10w30 synthetic for year round use, and 30w for only summer use.
5W20. I would choose a good-quality synthetic - Mobil 1, probably.