??Violent jerk/clunk when cruise disengaged??

[jalberring]

Hello,



I was on the interstate today with the cruise activated at around 70 MPH. I approached slower traffic and hit the cancel button. As soon as the button was pressed the truck slowed quickly and a sudden "jerk" was felt. This happened simultaneously. It seemed as if there was some play in the driveline which caused the jerk. The jerk felt somewhat like being involved in a low speed accident.



I then decided I would check this using the accelerator instead of the cruise. While travelling at 70 I quickly left off the accelerator and felt the sensation again. This seems to cause a lot of stress on the driveline. I don't recall any other vehicle that I have driven doing this. What could be wrong and is there anyway I could check the components for play/defects?



The truck is smooth any other time (shifting, accelerating, etc). It is just when letting off the accelerator quickly that this happens. If the pedal is slowly allowed to return this can be avoided. I really hate having to baby the pedal though.



The truck is a 2002 2500 H. O. 6spd with 2800 miles

Thanks in advance,

Jason

 

[mberry]

My auto does the same thing. I guess it's normal? I don't care for it either.

 

[Hummin Cummins]

Mine too. I'm thinking maybe a stretched transfer case chain is causing mine. I checked it out when I bought it (used) and the rear diff seemed tight. Maybe just the nature of the beast, but it I keep waiting for something to let go.

 

[mikel]

It's not a 4x4 thing

I'm not sure what causes this, but it's not the 4x4 transfer case. My 2wd does this too...

 

[Steve St.Laurent]

I think it's simply the amount of mass that is slinging around on our trucks. Same thing happens on my truck. What I do is I put my foot on the throttle before I hit the cancel button, then I lift the throttle slowly. On some of the later trucks I think that the throttle isn't directly connected to the cruise so this may not work. On my truck the throttle moves up and down with the cruise, so if I rest my foot on it before I hit cancel nothing changes. Keep in mind that you are driving a 7,000 lb + truck with a lot of mass in the driveline (axles, driveshafts, crank, pistons, etc). Have you seen the pictures comparing the rods on our trucks to the Powerstroke and Duramax? The more mass there the harder it is to slow it down.

 

[HillCountrykid]

My throttle pedal does'nt move while on cruise, but I press it down until I fell the engine getting more throttle before I turn the cruise off. If I don't it jars pretty bad.



Brian

 

[jalberring]

Thanks guys, At least it doesn't sound like anything is wrong with my truck.