I recently purchased a 1965 Fastback "C" code with a 4 speed manual that replaced the stock 3 speed manual. One of the problems that the owner disclosed was starting out in 1st gear. When I take off in 1st gear as normal, just as the gear grabs, the car begins to shudder. It progresses into an almost violent shake/jump and I have to stop. If I ride the clutch it will eventually get into gear but it is difficult to do everytime. It has been easier to just start out in 2nd. Previous owners mechanic stated that it was a bad leaf spring. What do you guys think? If it is the leaf spring, if I replace them, any suggestions? What are the advantages of the different springs? Thanks for all of your help and advice!

 

Well, a weak leaf spring can make the vibration worse, but the vibration is coming from somewhere. Check your clutch linkage to make sure everything is adjusted properly and that the z-bar doesn't have any lateral slop (you shouldn't be able to shake it back and forth in between the block and the fender). It's common for the z-bar bushings to wear out, which can cause exactly this symptom.

If this is not the cause, it could be clutch chatter caused by any number of things. Hot spotted flywheel, worn out clutch pressure plate springs, leaky rear main...

 

I would be very surprised if it was a leaf spring and not something inside the tranny. It seems to me that if it was a leaf spring, the car would vibrate no matter what gear you took off in.

 

Perhaps the clutch is burnished/warped or just worn out. A worn pilot bushing / bearing could cause a shudder as well.

I say the problem is most likely in the clutch... hard to say for sure on the internet though.

 

+1 to JMD and Starfury. Shudder on clutch release is almost always caused by a clutch releasing issue. Typically, it'sweak pressure plate springs, or a broken / loose spring on the clutch disk hub itself. It can also be caused by hardened spots on the flywheel due to excessive slipping. Or as starfurry suggests, the z bar linkage slop. By and far the zbaris the easiest to work on first. Then pull the tranny and replace the clutch, pilot bushing, TObearing and get the flywheel surfaced by a good auotmotive machine shop to ensure it flat. Good luck

 

Yep, weak/faulty pressure plate.

 

x3 another vote here for clutch/pressure plate. But i would check the motor mounts as well first.