New Noise. Ideas on culprit wanted

[Dirtleg]

So yesterday after a 540 mile 13 hour trip pulling about a 12-13K trailer(Before I even got to Atlanta the traffic reminded me of why we moved away last year) when I shut off the truck there was a heavy, rambling clunk. The best way I can describe it is it sounds like the drumbeat you'd hear after a cheesy one liner standup joke. And it shakes the truck. Did it on startup too. Now I am sure that if my arms were 6 feet long and I could crank and shutoff the truck while my head was under there to see and hear where the noise was coming from I could probably find it pretty easily. But since I am here by myself and don't have anyone around to start and stop the truck I cannot pinpoint where it's coming from. I know it's under the truck on the drivers side.

My first thought was broken motormount. The visual inspection didn't turn up anything obvious but it could be lifting I suppose and not leave any visible signs of it. Next thought was lost nuts on torque converter/flexplate connection. Truck drives totally normally the entire time it's running. Just on startup and shutdown it does this.

So what are the possibilities or has anyone else experienced this and what was the issue. Thanks for any and all suggestions.

 

[Diesel JD]

I thought your brother and Dad were in Atlanta, I guess they don't want to help out? I have no idea what it could be, sure hope you figure it out and its nothing that interferes with the rest of your trip. Be safe,
JD

 

[LCAM-01XA]

Dirtleg, have you tried spike-revving the engine while in park/neutral? When you do so it should twist the whole truck, open your hood and if you see the engine twisting but you can't feel the driver-side suspension unloading you may have a problem with the driver-side motor mount. Could be the passenger side as well, to check kick it in high idle and throw it in reverse, if you hear the clunk and see the engine jump a bit that motor mount is a goner.

 

[JeffMoss1]

I think it's your flex plate connection. That's kinda what mine sounded like when I didn't tighten the nuts connecting my flexplate to the torque converter enough.

Although it wasn't so much beat but a gong type of sound. On start up and shutdown and rattling while running when it was really loose.

Hope it's nothing serious.

I wish I could remember the thread on those studs, but whatever the thread I just bought some regular lock nuts from Napa and they've been working fine.

 

[Agnem]

Sounds like a likely culprit, since the DMF is famous for making shutdown noises. I suppose you already tried opening the hood when you shut down, and make sure it's nothing obvious.

 

[smoking89IDI]

You can start and stop the engine from the front, just make sure you are in neutral or park with the parking brake on, turn on ignition, make sure your out of gear AGAIN, now to start the truck just find the solenoid on the passenger fender to the rear of the batt and run a wire from the pos batt post (or right side of solenoid) to the little post with the wire on it on the solenoid, to shut down look at the IP and find the two electrical connectors on the right (drivers) side of the IP, the rear one is the timing advance and the forward one is the shut off solenoid, just pull it off and the engine stops (reattach to restart). Again don't do this if you can't keep it out of gear, I don't want to be blamed for someone running themselves over. This way is the best way I have found to "Bump" the engine over in small steps.

 

[Dirtleg]

Thanks for the suggestions and ideas. I've been busy as hell since I got back and we shut down our internet here in Virginia as we are closing on our sold house today. Truck made it fine to Virginia but man these hills around here are too much for it with the fully loaded trailer behind it. When I drove it to unload where I'm storing my tools at until we close on our new place (the 9th I hope) I was in 1st gear with EGT's over 1150. Yes this is on a road. Almost had to put it in 4 LO just to get up that hill. The trip from Atlanta to Lynchburg took 7 1/2 hours which really wasn't too bad considering.

Now that I am back in Virginia I have people around to help with the diagnosis.

JD I do have a brother and father in Atlanta but my brother was completely on the other side of town and my dad on a date. So hence I was by myself in that regard.

Well got to go I have to move 2 cars, a truck, gas powered welder and big air compressor out of there today. After I am done I have to pick back up the Kubota and be at closing by 4. Busy busy day today.