Freelander 1.8i 2005. I had what I thought was noisy hydraulic lifters. Initially I used Wynns cleaner but this didn't help, so I changed them all for new ones. When it starts up it sounds sweet, but as soon as it warms up the tapping noise comes back, I expect it to be the other way around...

I'm going to change the clutch master cylinder as I was told this might help with rough gear changes. But if it turns out to be the gearbox will I have to replace the master cylinder with another new one, or can I reuse the replacement one I used.