I did a b16a swap into my 90 crx DX and runs good... except when i shift really hard it grinds in 3rd 5th and sometimes 2nd i put 3 1/2 quarts of 10W30 into the tranny (thats what I was told would work fine) (have j1 tranny) Does anybody know whats wrong?

 

Syncros could be bad.

Despite what people will tell you, 10w 30 engine oil is perfectly fine to use in Honda transmissions, Honda only changed that after they invented something.

You fill the trans up until the fluid started to leak out correct ?

People will tell you to switch to the GM fluid, if the syncros are bad, anything is just going to band aid the problem.

 

I wasnt sure which plug to pull to check the tranny fluid... so I did the very top one and just felt like there was too much fluid going in so I stopped at 3 1/2 quarts.... do you know how much it should hold?

 

1.9 quarts

 

for the grinding i would use GM syncromesh friction modified as a temporary fix. I have syncromesh FM in my trans and its feels like butter. I used to have a hard time puting the car in gear and changing gears, and now its perfect. your trans should hold 3.9 quarts because i have a 88 4dr and it says 3.9 so it should be that same for you.

BTW that syncromesh is going to be kind of expensive ($12-15/qt) but its well worth it and when you go to by it make sure you say friction modified. You can pick it up at any GM dealer.

 

3.9 quarts sounds really high. As far as d-series go, its 1.8-1.9 quarts. I know the engine he has is b-series, but its not going to be 2 more quarts than a d-series. I believe its something like 2.2-2.3 quarts for a b-series engine, but I may be wrong. I would put some GM synchromesh in it. Fill it up until it starts coming out of the fill hole on the transmission on a level surface. If it takes 3.9 quarts for that to happen, then I guess I would be wrong. Drive the car for about 2 weeks and if the grinding goes away, great. If not, you will need some synchros.