well i drive an 89 civic hb and i believe the 3-4 gear syncro is beginning to **** on itself, it started a few weeks ago, when i shift from 3rd to 4th it grinds, especially at higher rpms. i thought at first i was just engaging the clutch to soon but nope there is definately a mechanical problem. so my question consists of 2 parts, is the syncro my problem, and how much does it cost and how hard is it to repair myself? any and all help is appreciated.

 

help, anyone?

 

try putting some lucas oil stabilizer in the tranny in addition with some 10w30 oil, i use about half a quart of the lucas and the rest of the 10w30, if that doesnt take care of it then its pretty bad, my 3rd gear was grinding, i put in the lucas and it took care of it...

 

Try using synchromesh.

 

what is syncromesh?

 

its a tranny fluid. u can get it at autozone, pepboys. it is 5 bux a quart. 3 1/2 will be enough (it was for me). and omg did it make a difference. It shifted smoother, less grind, and u can shift so much faster . my advice, GET IT.

 

grinds from third to fourth? sounds like a clutch to me.I had a buddy that had a 3G hatch and it grinded from 1st to second and two days later the clutch went out.It wouldnt hurt to check it,to be on the safe side.

 

Id go with the bad clutch theory. 3-4 gear should be smooth, make sure your clutch adjustment is correct, unless you have a hydro then you might need to replace your clutch setup.

Got any other issues like high, uncontrollable revving at high rpm or mph? Clutch sound like its slipping or any other gear grinds?

 

no clutch isnt slipping at all, the only problem is the grind from 3 to 4.