I was hauling about 7k for 350 miles yesterday when I stopped for fuel about half way. And when I shut off the motor I heard a bad rattle coming out from under the truck. First time I'd ever had it happen and I was a little concerned (turned my head and perked my ears like a lab puppy). Truck ran fine, pulled hard with the cruise on 72, and I didn't notice any noise while driving or tranny slippages. Today I still have the same noise. Put into R and D and I notice a little vibration (shutter noise) coming from the trans./driveline area. No noise in N. But, when I shut off the motor, the "rattle/vibration/shutter" is very loud and very noticeable.

I've been doing "searches" for about an hour on "shutters, vibes, trannies, carrier bearings, u joints, etc." but I can't find anything that would make that kind of noise on motor shut down, and I don't hear or feel anything while moving.

Just searching for ideas on where to start looking.

 

I would think possible exhaust system noise. These engines shake quite a bit on shutdown. Check for loose clamps or cat hitting transmission crossmember. Also if you have running boards check bolts make sure they are all tight. Flex plate on trans will give you loud rattle noise if it is cracked. Noise will usually go away in drive or reverse since torque convertor is under load then. Will be loudess in neutral or park. Good Luck

 

I would go with broken flex plate, if noise is loudess near trans bell housing. Will need to pull trans to replace if broken.

 

Would I hear something while driving it the flex plate were toast? Or, at least feel something?

 

My 2500 made similar sounds once, turned out to be flexplate/torque converter bolts were loosening up. After some quick wrenching, sound was gone for good. Easy fix for a change. Worth checking out. If you leave the truck in gear when you shut it off is the noise gone?

 

mine has a fair bit of rattle on shutdown also. i have the g56 trans though. it won't make the noise if i keep the clutch pedal depressed when i shut it off. any ideas, or is it normal?

 

Mine has always shook vilolently on shut down clutch in or out.The owners manual does say that with a stick to push the clutch in when turning it off. I think they all do it.

 

Mastercaster, that is totally normal....

 

thanks, i didn't think anything was wrong. it drives awesome and works great. my ford diesel just never did that on shutdown, so i wondered. thanks for the assurance.

 

Same noise here. Mine does the same when I put it in D, N, and R. Its a diesel they make all kinds of weird noises :0

 

Just dropped it off at the dealer. They will tear into it tomorrow and let me know what they find. The more I read, the more I'm thinking flex plate. $$$