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i have got a 97 Civic (6th Gen) 4dr with Manual transmission. I have replaced the stock engine with a used one as first one died, also replaced clutch at same time.
Since then I started getting this grinding noise from transmission when car is idle. If i press clutch the noise goes away, it seems like its some bearing in transmission that's making noise. My mechanic told me at the time when i replaced engine that transmission was low on fluid, so he added (replaced).
I am not sure if he added Honda MTF or Motor Oil.

So now i am in dilemma to replace transmission or not as this seems like an expensive deal and car isn't worth that much.

My second thought after reading in these forums is that it seems like working on transmission isn't very complex, but i am worried that how can I remove the transmission without pulling up the engine (which definitely needs to be done in mechanics garage), or if DIY is possible please let me know.

Last Solution is to replace transmission and let a mechanic do all the work. Any idea how much it can cost? I am in canada.

What happens if I keep driving the car, as i have already spent a lot of money on it. What can I do to so that this problem escalate further without replacing the transmission.

As you can guess I am looking for the cheapest possible solution as my budget is almost depleted.