depressing newbe question of the day

ok, i have a 318/904. stock
occasionally shes askes me to mash the pedal, if I do this I hear crunching/grinding sounds which seem to come from the transmission. This will only occur in first few seconds of acceleration.

If I mash pedal after im already going about 20 mph, no such sounds.
If I'm gentle in acceleration, no such sounds.

I do not feel any slipping of gears, but dont have my tach on to see (if thats necessary)

fluid level seems fine, though tranny does leak a bit at u joint.

now I have to fight the urge to mash, because I dont want to damage, but I WANT TO MASH.

Is my transmission going? no plz no :prayer:

secondly, can you analyze transmission oil to diagonose wear as you can with engine oil? anyone done this?

thanks