clutch pedal has a thumping feeling and sound when i push in the clutch pedal. i have put about 20k miles on a oem clutch. is there any way the engine could get mated to the transmission wrong if all the bolts bolt up? could lack of grease anywhere cause this vibrating thumping problem? if i tilt the clutch slave cylinder so it angles downward (boot side of the slave towards ground, brake line end higher) then bolt it up, it seems to significantly help with vibrating and the thumping sound. now thumping is kind of intermittent. seems to happen mostly low rpm when shifting now. any ideas what i might have done wrong?

 

so i unbolted the two brackets holding the bottom of the transmission to the engine (upper bolts kept in place) drove around for a while and i guess it must have vibrated something back into alignment because there is no more thumping sounds anymore. strange