managon_5

I've been getting a grind in 3rd gear everytime i get on the throttle and quick shift. I've even tried granny shifting and it still wants to grind. I've tried researching what fluid to use in my tranny to make everything smoother but i haven't been able to come up with a conclusion. Please voice you opinion.

These are the products I've come across:

Pennzoil Synchromesh
Honda MTF (the new stuff is supposedly reformulated and works better)
GM Synchromesh
Royal Purple

FlewByU352

welcome to the club. i've been told its many different things. transmission fluid could be low or syncromesh might cure it (GM supposedly makes the best). I was told my slave cylinder is going, which could very well be I have a squeak but its only 3rd and thats usually the 1st gear to go out on Honda transmissions. I was told my syncros just need to be replace, my clutch needs to be replaced... I havent done anything yet but double clutching in it, it wont grind at all which is why a mechanic told me the slave cylinder because 2 kicks and it builds up enough pressure. idk

OneFire

I have the same problem as well. Quick shift into 3rd it grinds. Granny shifting it goes in ok though... But what a pita, need to change tranny fluid to see if that helps.

Arcitekt

your clutch is almost out or you running low on T-fluid. royal purple is good stuff.

rehaf

Mine grinds at times going into 3rd too. My clutch and slave cylinder are fine. I changed the fluid and used the new Honda MTF and it helped a little. I might try the GM stuff next.

Vindicator9000

Warning, informational content follows lol:

Grind doesn't have anything to do with the clutch, or master or slave cylinders. It's all about the sychros.

Ask me how I know... it's cause both of my transmissions have mildly grinding gears both before and after new clutch/resurfaced flywheel. And so does everyone else I know who has grinding Civics. It has everything to do with how modern transmissions work, and their wear parts.

Double clutching definitely should make most grinds go away, but not because of any kind of pressure in the cylinders. Read up a little on transmission theory on howstuffworks and wikipedia. Double clutching works because it matches the speeds of the input shaft and the gear that you're going into.

Before helical gears and synchros were invented, drivers had to double clutch on every gearshift. Truckers still have to on a lot of vehicles. And so do Civic drivers when their sychros are going out. Because the sychros aren't matching the speed for you, you either have to *very carefully* rev match, or double clutch.

Also, before the days of synchros, the gears would take the brunt of the wear, and transmissions would tend to go out quicker than they do now. Synchros help save your actual gears from wearing, because they prevent them from grinding.

Sometimes GM sychromesh band-aids the problem. Sometimes new MTF can help. But your grinds will keep coming back until you tear into the transmission and replace the synchros.

Added informational links:
http://en.wikipedia.org/wiki/Double_clutch
http://auto.howstuffworks.com/transmission.htm

I hope we've all learned something today.

FlewByU352

good info man, atleast i wont ever have some mechanic trying to get me to replace the clutch and all of its components. I dont plan on keeping my D16Y8 forever so I guess as long as it doesnt need work an it stays in gear for the remained of it being n my car its all good. It sucks so much to fly through 1st and 2nd then have to double clutch and get back on it. Even though it taught me to double clutch pretty darn fast it just seems to lose the fun because its not as direct babying it into 3rd.

93egSLEEPER

just to throw this out there honda trannys were not made to run on synthetic oils. the synchros are engineered to be DRY when the come together in each shift... not coated with slimy gooey synthetic. get a third gear and replace it. dont just cover up the problem and kill your whole tranny

FlewByU352

thats also interesting info about the synthetic. So syncros wear based on what? hard shifts? why does the 3rd gear usually go out first? I would think 2nd gear takes the most abuse by the time you shift to 3rd your already doing 50-55mph or so. I'm just trying to get a crash course on all my transmission questions lol

93egSLEEPER

most people on the streets dont do 1st to 2nd pulls, its getting on the freeway, racing on city streets and all that that takes place shifting 2nd to 3rd that wears them out the fastest. synchros in a honda are angled/curved making a "dry" fluid better cause it allows for a more positive grab when shifting. synthetic with its more slippery nature can also the synchros to be "wet" or "full" of oil taking up space for the synchros to mesh together more solid. YES it may feel like smoother shifts, but its putting more stress on the synchros.
if they were straight cut like old school chevy muncies you wouldnt even need to clutch in to shift but rather just push and pull.... my chevelle is that way.

300whpej

^this. it might be your 3rd gear synchro may be bad, but i would check the clutch and fluid first