So i purchased a rebuild transmission for my d16y8 ek civic. installed the thing and emidiatly it would grind going into 3rd gear only, every other gear is smooth. this mainly happens at higher rpms but is basically only avoided by pressure on the shifter slowly with the clutch in untill the revs match if that makes sense. so called (synchro-tech) and explained the problem and the emidiatly tell me its not the trans its my clutch. after much debate they tell me i need to drive it more and it will get broken-in and the issue will stop. after 500 miles the issue never got better so i called them back and they sent me a replacement, short story is new trans same problem, now over 500 miles on second trans same issue again. What are my options? What would cause this? And please no one say it my clutch.

 

Generally speaking a D-series third gear grind is due to a worn 3rd/4th sleeve and worn third gear. What fluid?

Also, this really doesn't sound like synchrotech. I'm not saying it isn't, but I can't imagine anyone telling you to keep driving something that's grinding with the idea that it needs to be broken in.

 

I used 10w30 motor oil as Synchro-tech instructed me to. And i was a bit suppirsed myself that they told me it would just go away with mileage, but that was after the arguement that it was my problem caused by my clutch, when if it were the clutch wouldn't you think it would grind going into every gear?
Also it is only an issue during upshifting never downshifting.

 

10W30 should be fine.

Generally speaking yes, or you'd have issues getting it into 1st. That said, have you looked at the disengagement height?

 

What did the clutch, pressure plate and flywheel look like when you had the trans off? Is there a leak in the clutch system (master or slave cylinders)?

 

things happen to the best but i cant see syncro tech sending two bad ones out...what kinda clutch do u have and has the things like the slave cylinder ever been replaced? and like mentiond have you checked and adjusted the engaugement height on the clutch pedal?

 

94EG8, i have not checked engagement height, what is that and how do i check it?

AQUAFINA, the clutch, pressure plate, and flywheel are all brand new i installed them when i bought the car, and the clutch master/slave cylinders are the stock pieces.

4G HATCH i thought it was weird myself but not enough experience with transmissions to know were to go so just assumed it was the trans, cant remember what brand the clutch is, but again i have not adjusted anything cause i honestly didnt know i could.

any info on how to accomplish the adjustment would be great, also would you recomend that i replace either the clutch master cylinder and/or slave cylider even though neither are leaking? are they a time change item?

 

See this post for details: https://honda-tech.com/forums/showpo...80&postcount=6

 

Thanks

just went out and checked it, pedal to floor is 6"
about 1" of initial slack
clutch starts to engage at about 4" from the floor and seems solid all the way to the floor.
My measurement was to where the pedal contacts the carpet not exactly as the illustration suggest but effective enough you think?
As per the illustration it seems the disengagement height should be good correct?

 

I would check the syncro for third gear. how many miles have you put on the clutch? honestly speaking, if the two input shaft was installed without the correct spacer then you would get a grind but you would notice it on most gears. inspect the trans. i highly doubt anything is severely wrong with the clutch/ pressure plate from the way you describe it.

 

There seems like a fair bit of free play, nothing horrendously out of wack, but you you wanted you could turn the pushrod in towards the firewall a couple of turns to see if it helps.

 

JOHNVANDYK- The clutch has around 1000 miles on it the trans has about 500 miles on it, but as i said before the trans is a rebuilt from a reputable company so really shouldnt be an issue espescially seeing as i had this issue with two different transmissions from the same place.

94EG8 - Thanks for your guidance i will adjust that pushrod tomorrow and see if it improves.

 

Ok looked under the dash today and the clutch master cylinder is leaking, but its not alot, it has the consistency of oily grafite though. not sure what thats about? but i do need to replace it, also i went to and adjusted that pushrod, i screwed it in as much as i could which was only about two turns because it was already maxed out on adjustment.
Why would it have already been maxed out for adjustment, does that mean this is most likely my problem, also the little adjustment i mad seemed to do nothing for the grinding going into 3rd gear.

 

Put a new master cylinder on and go from there. That pushrod is usually nearly maxed out that way. It may or not be your issue, but it is bad. I've seen some of them leak for years before it became a problem, sometimes it happens sooner than later.

 

I believe we were advising to avoid high RPM shifts on the new clutch until it was fully seated in. I looked up the build notes on the transmissions and we replaced the 3-4 shift fork, 3-4 sleeve and synchro on both builds. It seems unlikely that two different transmission both with all new 3rd gear parts would have the same problem. If The clutch master and adjustment doesn't resolve the problem and you feel it is in the trans, send it to us we will be happy to inspect everything inside for you.

 

I will replace the clutch master cylinder as soon as possible then and hope that does it for me.

I dont doubt that you guys truely rebuild the inside of these transmissions, i mean the attention to detail on the outside was spot on, your company clearly takes pride in what you deliver to your costomers. Im just confused at this problem.
We are basically talking about the simplest version of a hydraulic system any one could deal with, and i understand that if there is any type of leak it would not work but, it clearly does work because every other gear works precisly as it should and at any Rpm!

But with that said i will replace the master cylider and post back with my result.
And thank you guys for your help.

 

I agree that the master should affect all shifts and not just 3rd. Take a close look at the linkage and shift bushings to see if anything looks worn and keep us posted on what you find.

 

I will do that thank you, i will be changing both the clutch master and slave cylinder just for peace of mind.

What is recommended for fluid in that system sense it will be drained completely?

 

DOT3 brake fluid.

 

awesome thank you

 

So changed both master and slave cylinder, turns out they both had slight leaks nothing crazy, but pedal feels much better now, didn't get to drive the car as much as i wanted to after tho had some rubbing issues with the new wheel tire setup, the one time i shifted into third the grinding was lesser than before, still slightly there but i think with a little more adjustment it might be gone completely, will find out tomorrow.

 

run syncromesh fluid.

i see that syncrotech said the 3rd gear sleeve and syncro were replaced..but what about the syncro spring? and what about the 3rd gear itself? how were the dog teeth on the 3rd gear?

 

Drove around a bit today, and the grind has certainly improved, but it is still an issue, it's about half as bad as it used to be. So where can i go from here? Can the guys from synchro-tech say anything on fluid? syncromesh fluid ok to use? they were very adamant that i only use honda fluid or 10w30 the last time i talked to them.

 

of course its perfectly fine to run syncromesh! its the best fluid you can use in a stock trans. the LAST thing i would do is run the new oem honda mtf. that stuff is like water and caused me all kinds of grinds in various transmissions. you can pickup some pennzoil syncromesh at autozone or oreilys. it is what i have always ran in all my transmissions. i have rebuilt about a 100 honda transmissions.

using syncromesh would be best but there is still a issue with your trans and syncromesh will not fix it. you need to confirm if they replaced the syncro spring and/or 3rd gear or if they didnt what were the condition of the dog teeth on the gear. if they put in a new syncro sleeve and the dogteeth on the gear or the spring are worn, it will grind like you are experiencing.

where are you located at in missouri? i can open up your trans in under 5 minutes and tell you what is wrong.

 

I'm in Warrensburg, its warranted through synchro-tech so not sure what i should do?