Truck lunging forward

It's the AC compressor kicking on and revving your engine up a little. It's just a thing these trucks do. I posted a thread like this almost exactly ten years ago asking the same question. You get used to it.

 

Was creeping into my garage last night....just a few more inches.....and it took off!!! Somehow I didn't put it thru my wall.

 

I have the same thing but it's very infrequent. I don't believe it's the A/C compressor or axle wrap. I think it's what this article describes.

 

Of all the explanations I have heard & read over the years, this makes the most sense to me. Thanks for posting it!

 

I think the doc linked above makes a lot of sense, but just to add to all the confusion I also think axle wrap does comes into play here. On my '15 which had the TSB leafs from the factory it did this for me. Installed suspension lift including a full Deaver leaf pack and I no longer had the jolting/lunging problem. I honestly forgot I ever had this because after several years on the new leaf pack it has not returned.

My only rationalization of my own problem is that the factory leafs, even the TSB leafs, are such garbage that they bind when wrapping at a full stop. The A/C comp kicking on and simultaneously causing engine RPMS to increase momentarily is enough to unload the driveline from that wrapping and that gives your jolting/lunging like you got rearended.

 

I have had the AC kick in and the truck moves a bit but not a violent jerking like the trans issue posted