Gearbox Clutch CVs Driveshaft/CVJ condition check

MrBen88: Hi, New to this all, but van seems to have weird habit of occasional shuddering / juddering 

at speeds between about 50 and 65. It's a 1980 2.0L Aircooled.

Doesn't happen all the time and if you ease of the accelerator and then put foot back down that usually cures it, but quite worrying. Any help appreciated.

Splendiferous:Check your drive shaft bolts.

MrBen88: Thanks! Not sure if it's van or engine as not consistent when it happens. Is checking the driveshaft flange bolts and CVJs (what are they?) first something an idiot with a haynes manual and no idea could do on my drive?

What are the potential consequences?

MrBen88: PS - What am I checking for?

Old one: Serious!

Each side of your gear box are the drive shafts, that connect the g/box to the wheels. Grab hold of these and give a good shake, also where they fit to g/box are bolts. Make sure these are tight

HarryMann:

Wear gloves to check that shaft, get a good grip and as The Old One says, side to side is OK (drivehsaft splined into CVJs through the boots), up-down and fore-aft bad, also rotational play (clunking) bad of course. Look for split boots and black grease coming out. Can squeeze boots gently to force grease back into joints to prolong life (one inboard, one outboard inside the suspension radius arm, pe side).

Then check all 6 bolts of each joint, most likely to be loose will be those on inboard joint but check them all visually at least. Two types of bolt head, hex socket cap heads, or 12-point spline drive (No. 8 size I think). Need suitable bit for your socket set. You do have a full socket set, 3/8" or 1/2" sq. drive metric, a must really, if you own one of these vehicles.

Torque is 28~33 ft-lbs, 30 will do. Failing a torque wrench, if any are loose at least tighten them up (40 lb pull on an 8" wrench, don't hang on it with all your weight) and clean out the socket heads before inserting the bit and keep the bit dead straight into the socket. Inspect for mulleringitis before tightening and be circumspect about tightening if animals have been at those bolts.