Well is usually one of these 3 things. Syncros, clutch or blown tranny mounts... its up to you to figure out which on it is...

 

I would do the most inexpesive thing first. I had a problem with my 93 Civic Si grinding going into 3rd.

When I changed the tranny fluid only a pint came out and it's supposed to take 2 quarts. Plus I think the fluid the previous owner used was super thin oil. After putting some fresh fluids in no grinding and super smooth.

 

Yea? You see that's what I had in mind first...the trans. fluid...i wanted to put syn. gear oil but never got around to it. I guessing, it has never been changed or checked on...im gonna do that first.

 

use Honda brand MTF, seriously it's about the only thing that works reliably.

 

Or Gear-mesh (I think that's what it's called) from a GM dealership. Heard that works wonders too.

But yeah use only Honda MTF in the tranny case. Some other tranny fluids don't work well with Honda trannies and causes more problems.

 

i have bad synchros in mind. 3rd won't work... 4th grinds... 5th grinds and slips out. i bought a replacement tranny... $200. a synchro set is substantially more than that

 

The other tranny fluids "don't work well" with Honda's because they are a specific "transmission fluid" with viscosity ratings around 70-80. Honda's use oil with a lower viscosity for their tranny fluid, which is very different than other cars, most use a "transmission fluid" which has a higher viscosity.
Honda's MTF is essentially a low viscosity oil, and therefore you can use any type of oil, with comparable viscosity ratings...

I've always used Mobil 1 Synthetic oil in my tranny and never had any problems... (not sure of the viscosity, it's in my Haynes manual at home, but I think it's a 30 weight oil)

 

I'm actually starting to have some problems with mine too. 4th and fift grind and 1st does only every once in a while, i went to change the tranny oil only like a cupful came out and i replaced it with 2 quarts, did nothing for the any of my problems, was told possibly the syncro's anybody know? how much synchro's cost?

 

syncros are cheap, like 30 each, it's the labor tearing apart that will kill you.

The old owners manuals called for 10w-30 grade SF or SG. However the oil standards have changed and you will be hard pressed to find SF or SG oil now. I don't remember the specifics but the new oil (SJ?) doesn't jive well with honda trannies after a while. I think it had to do with the detergents. Hence the reason you only want to use Honda MTF. 10w-30 will get you buy but Honda MTF will help your tranny last longer.

 

where you buy em from?