Shifting from park into drive

[Zolton]

I've only had my slightly used RL for a month now and am still getting used to it. When I first start it up from cold and shift from park into drive it seems to click into gear then after a very slight delay, bumps into "drive mode". That is to say I can hear it engage before I can feel it engage (if that makes sense). Is this the norm? I can explain further but I think that describes it pretty well.

[csimo]

Yes, this is considered normal. I no longer even notice it.

[Zolton]

Hmm. Anyone know why there is the delay? What happens if you are being a knob and hit the gas before the transmission decides it's ready to go?

[shovelhd]

The same thing that happens when you stick a fork into an electrical outlet. BOOM.

[CBRidgeJockey]

then it clunks real good and loud.

[MikeT]

The delay, iirc, is due to the way the ECU tries to reduce drivetrain lash during shifts. During shifting, the throttle amount is reduced to decrease the load, shift completed, the throttle is placed back in the original position (All by the ECU via the drive by wire throttle). That's my understanding of the issue. If you get on the gas before the second clunk, the truck just simply moves normally.

[Zolton]

Originally Posted by shovelhd

The same thing that happens when you stick a fork into an electrical outlet. BOOM.

Hey....it's a knife not a fork. I'm not that stupid

[galamo]

I believe when you go from Neutral or Park to drive the transmission engages in second gear initially then drops into first. This smooths out the clunk that you get when motor torque is first applied to the drive line. So I think you hear the engine and tranmission engage but because you are in second at a low RPM there is not alot of torque through the drive. The downshift to first is what you feel through your seat.

The downshift is quick enough and the computer really has control of the throttle that if your were to gun it in neutral and drop it into gear you would probably just take off abruptly after a moment's hesitation.

Its just an attempt to refine the powertrain.