Clutch clunking

[Rascal21]

I`ve got the same "problem" in my TA40 (Which I slammed a T50 transmission into), I havent had any real problems yet (Been a year).
Happens specifically when I put it in lower gear with clutch pedal held in, can hear a sound like WHIIITIITITITiiitititittttrrr, almost like a turbo

If you however feel that it is unsafe, go ahead and replace the release bearing, it`s not an expensive component, keep the old one for spare

Btw, Not to offend or sidewalk you, Homem Bomba, in ANY way,
BUT putting grease into the clutch slave cylinder, as well as WD40/WD 5-56 and so forth ticks of EVERY warning bell and defies every instruction out there, because brake fluid is what keeps the seal, these components dont take well to grease or de-greasers (And in fact speeds up the corrosion process on the cylinder walls/bore)
Just clean with brake fluid and take your time would be my advice (Based on previous experience), in fact, if you absolutely WANT to make sure, a disassembly of the slave cyl to inspect the cylinder bore is recommended.

If corroded, replace both master and slave cyl.

My humble .50`s