it was probably just clutch chatter. When you're letting the clutch out when you take off there is a point where the speed of the flywheel (engine) and the clutch plate (transmission) and the pressure on the clutch are just right where rather than slide or slip past eachother it does a slip, grab, slip grab thing and thats where the shaking comes from. Its something that is more common on large clutches like on big trucks.
When it happens there's 2 things you can do, let off the gas a little to let the engine's rpm drop and equal the rpm of the transmission so you can let the clutch the rest of the way out, or push the clutch in and try letting it out again.
There's 3 major things that can cause chatter. A warped flywheel or pressure plate casued by overheating. An oil leak that is lubricating the clutch. Or the way you let the clutch out.
A worn out clutch will be more likely to slip in higher gears than in lower gears. You'll know when its clutch time when you're under hard acceleration and letting the clutch out fast while on the gas real hard and the engine doesn't come down to where it should for that gear until a quick second after you let the clutch all the way out. When that happens, stop going hard immediately and go easy on it and make arrangements to have the clutch changed as soon as possible becasue you're on borrowed time. The clutch lining is very thin and the rivets are very close or are hitting the flywheel, the lining could crack and fly apart and then you'll have to call a tow truck. I've nursed a bad clutch for a month waiting for warmer weather so I could change it comfortably.
