If its shuddering when you dip the clutch it could be a broken spring in the friction disc.
Crawl underneath and make sure that the clutch disengages all the way, grab the release fork and shake it back and forth you should be able to feel a minute amount of play between the release bearing and the cover if its not disengaging properly check you have the correct push rod length for your current setup and check to ensure that the slave cylinder is of the correct size.
Push rod too long, incomplete engagement. (Only has to be a fraction to slip under load)
Push rod too short, incomplete release (cant select gears)
There are differences between them
Check to make sure the release fork is not bent for the same reason.
Pull the boot off the release fork if its been slipping a lot the bellhousing will be full of dust and will stink, also check for lumps of detritus that shouldnt be there ; bolt heads friction material etc. Check these before you commit to pulling the transmission
Theres not much else you can do without pulling the tranny.
Parts should consist of:
Flywheel
Flywheel bolts
Spigot bearing
Clutch disc
Clutch cover
Clutch cover retaining bolts
Release bearing
Clutch fork
Release bearing retaing clip
And release bearing pivot ball.
![Head Scratch :headscratch:](https://board.marlincrawler.com/Smileys/marlin/headscratch.gif)