(context, my rb25det pull type gearbox was making a grinding sound on idle and when accelerating in the lower rev range but goes away with the clutch pedal in) I got a pretty hefty bill recently which I'm not overly happy about (only because the problem is still there), my mechanic told me a while back that the grinding noise I had in my car was the spigot bearing, long story short but he pulled it out and it looked like brand new, he said that it wasn't lubricated and ended up putting in a new one that was. I didn't think much of it, until I turned on the car went for a drive and noticed the car has the EXACT same sound, nothing has changed.
He said it had some noise which I have no idea what he's referring to and I told him that my gearbox was still grinding, when we went for a test drive he said it was normal. There's no way a grinding gearbox is normal. You can really hear the grinding if you're in a higher gear but your speed is low, I guess makes sense as the gearbox is working harder.
That's one issue, the other issue I noticed is there is a loud rattling sound especially when I start up the car and especially as I go up my driveway. Some other things to note is that the previous owner did a dodgy clutch install and also stripped one of the threads on the flywheel bolt which my mechanic all fixed up and put a new clutch kit in, which I'm not sure if that has something to do with it. I know a bit about the history of the car, it was definitely thrashed and tracked.
The car itself drives fine and doesn't crunch through the gears, there was wasn't much metal shavings on the gearbox. Do you believe my mechanic misdiagnosed my car? I'm trying to decide what next steps to take, I imagine I'll have to rebuild my gearbox eventually.