i have a 90 civic d15b2 hatch and when i shift to 5th gear it makes a grinding sound except if the rpm is below 1k then it shift find without grinds.can anyone help me fix my problem. THANK YOU

 

Sounds like your synchro ring for fifth gear is worn and not allowing your engine crank to sync with your fifth gear when shifting. This brass ring basically slows down the engine RPM so it will mesh at the right time when fifth gear is engaged.

The reason it does not grind when you shift until the rpm's goes below 1,000 RPM is because that is the optimal range for the fifth gear to mesh with the engine crank at that speed. This is call timed or timing shifting.

You will need someone with manual transmission skills to change the synchro ring. It may be cheaper just to get a salvage unit.

Dongss