elptxjc, why do you keep saying its driveline play when I have posted that the clunk can happen with the weight of the truck resting on the driveline in park (on an incline) with no parking brake set? where is the play in that case?? Also, why does it happen in Neutral??

 

What else can it be? Think about it. And yes, it'd do it in neutral too. When engine starts, oil viscosity causes the torque converter (and motorcycle wet clutches) to move even when not in gear. If there's play (and there's always driveline play), the driveline moves until suddenly stopped. In our case, it's just a tiny bit, but enough to clunk if not dampened. What exactly clunks is debatable (tranny or differential), but something is, and it shouldn't be detrimental... unless it gets worse. THAT was my point. If you want to bend out of shape just for that, be my guest . But life is too short for that IMO, brother. By the way, the parking pawl in our transmission might not bind the drivetrain (I'm not familiar with it), so that could be your answer .

 

To the guys who said that their service advisors and mechanics were in awe when they heard the clunk: Your service advisors/mechanics are good actors. Every f150 make these loud clunks sometimes. Esp on a warm start. Not saying it's a good thing, I'm saying they all do it, and anyone who is around these trucks alot, like them, would know it.

 

to elptxjc and jalcon: these trucks shouldn't clunk like this. Period. i have worked on cars, trucks and 18 wheelers since i was 10yrs old. There is no way you or anyone else is going to convince me that any car or truck should do this. Life is too short to be saddled with a vehicle that doesnt work like it should. Jacon knows this already, ask him why he has a 2019 F150.

 

Hey all,
I'm having the same clunk. Even when shifting from drive to reverse you can hear a bad clunk and feel it. 18 2.7 4x4

 

Don't know about the Camaro but the Corvette is 8 sp.

 

My '19 F150 5.0 does it occasionally. It is definitely engine and not driveline, parking brake, etc. My theory: The 5.0 is really high compression, 12.5:1 I believe. Anyway, It depends on where in the cycle the engine stops. If it stop where the cylinder next to fire is just before TDC, the engine will kick back because of slow rotation (remember it fires before TDC) . This happens on aircraft engine some which is why we crank the engine and get it up to speed and then turn on magneto, and also why Model As and Model Ts had spark advance/retard on the steering column. Try to start a Model T with the spark advanced and it will kick back and break you arm.

 

Juan, i guess you havnt watched the videos where the driveshafts are moving when the clunk happens??

 

No, didn't watch the video.

 

Maybe also didn't note that the clunk happens with the 2.7 and 3.5 motors also.

It's driveline.