I have a 78 z28 with a 350 with a manual transmission in it and sometimes it will violently shake when takin off from a stand still, any ideas on what could cause that would be greatly appreciated, also sometime the car will slip out of 2nd gear when im not accelerating or braking, but it has never slipped out while im accelerating. Could these be related? any opinions would be helpful

 

Sounds like you're describing clutch chatter. Does your clutch slip at all, or does it grab good and tight? If the clutch has ever overheated (smoked it) the surface of the flywheel or pressure plate could have some checks (splits) and that could be what you're feeling.

 

I had this occur once in a pickup when the bell housing bolts had backed out very slightly. Give them a quick check to make sure they are tight!

Rick

 

its never slipped anywhere but out of second gear, but sometimes it feels like its a little bit harder to put into gear, but i did have my clutch redone not to long ago and im pretty sure i got a new flywheel at the same time. I dont think i ever overheated it, would i just have to take it all apart and look at the flywheel to check?

 

Thanks for the advice i will have to give those a check when i get home tomorrow

 

let us know how it goes.

 

Could be the rear end,bad posi clutches getting ready to go out will chatter like that sometimes.
Does it do it more going around corners? that would indicate the rear end as a possibility.

 

Would a posi clutch failure knock it out of gear though?

 

No, it wouldn't. And a lot of times, changing the rear oil and adding the posi additive will take care of it. I just did the oil on my 79 Vette with a chattering rearend, and it fixed the problem. The chatter was only noticeable at slow speeds, and while turning obviously. Going straight, the clutches are locked together, so no chatter. And it looked like the oil had never been changed.
Another thing to look at is the motor mount, primarily the drivers side. If the mount is torn, the left side of the engine will lift and could mess things up.

 

Nope but then there may be two unrelated problems going on there.
'69 is right about the oil and posi lube,something to look into if you find the rear end is chattering before it's too late hopefully.