Why my truck jerks

Drive line....... Carrier bearings. Yokes.

 

Have a mechanic ride with you.

 

it could simply be the torque of the engine... If you easy off the pedal and easy back on it will probably be smooth. However if you suddenly let clear off the throttle, then just as suddenly slam the throttle back down, the amount of torque created is tremendous... Especially in lower gears. I have seen thus many times before in inexperienced drivers... Its not a car you're driving, you have to feather that throttle.

 

I had a 12 FL that also did that. It wouldn't step in to the throttle smoothly like other trucks I've driven.

It was a delayed throttle response that basically slams in to position. Can't be good for the drivetrain but the truck was a lease truck that gets traded every 3 years. It was nice when my 16 arrived and the truck went bye bye.

Could also have looseness in the 5th wheel. Every LOCAL truck I've driven has that. You slow down sometimes the trailer comes forward if you brake hard enough. Then back when you throttle up. An adjustment can fix that. The plate I have now doesn't have an adjustment. I"ve noticed that lucas 5th wheel grease helps tremendously with that also. Compared to the jelly grease shops use. It also last soooo much longer.

You may or may not have the same symptons though.

 

We can all speculate for days on this but @Ridgeline got it right.

 

Too much play in the transmission, u joints or the rear ends.

 

Mechanics don't seem too interested in test drives these days.

 

Check motor mounts, and cab to frame mounts while you’re at it. Also torque rods on axles and cab. Along with everything already mentioned

 

Even wore out motor mounts. Follow ridgeline's advise..if no solution has been reached.

 

I have yet met a mechanic that won't do a ride along when you pay them. It is an easy hours worth of money in their pocket.