My truck is a manual, and i know this is typical of manual transmissions (this problem happened on my last truck, just not as bad.)

When shifting down gears, and coasting a little while still in gear, the truck bucks a lot and chugs and chugs and jerks back and fourth the slower I go.

Is there a problem with the clutch or clutch system?

It chugs badly enough to make me put a thread about it and see what others think, that's how bad it's gotten. it's fine in higher gears and higher speeds, but low gears suck.

 

What are the rpm's when it starts "bucking".

If they are low when it starts bucking, that's normal, especially in first or second gear.

 

how slow? because here in the city im constantly going between 1st and 2nd but my truck only bucks when i dont use the clutch while going around 5mph.... so how slow is your "slow"?

 

my truck was bucking like that acouple weeks ago. it was because my intake tube had a crack behind the air flow sensor. So the computer did not know how much air thye engine was getting. At first i thought it was the fuel filter but when i started going through the engine compartment i found the cracked intake tube. I just went to a wreckin yard and replaced the cracked intake tube with a new used one.

 

you shouldn't idle it down below 1000-1100 rpm in any gear other than 1st or 2nd, and then not below 700-800 in those two. the engine does not have enough torque to operate smoothly much lower than that...
...and it'll also wreak havoc on your rod bearings if you lug the engine like that.

 

The bucking starts aroung 1500-2000 RPMS, and at speeds about 10 MPH. I'm usually in first or second gear when it does it the most.