WORKING ON A 1997 F350. WITH A 7.3 AND STD TRANS. WHILE DRIVING AND PULLING A LOAD ON A HILL. AND JUST BEFORE STOPPING THE ENGINES RATTLES ALOT. THEN, WE TAP ON THE THROTTLE AND THE ENGINE SMOOTHS OUT. ANY IDEA!

 

I'm hearing a similar rattle on my F250 HD with 7.3L PSD. I hear mine intermittently when decelerating, and it goes away when I tap the accelerator.

The sound kind of remainds me of big rig diesels when they have the big noise out the exhaust when they use the engine to brake. Could it be a problem with the turbocharger locking up and acting like an engine brake? I'd be interested to know what it is.

Tom

 

You may have the dual mass flywheel going out. They will rattle at low rpm.

 

Powerstroker,

Thanks. I think you hit the nail right on the head. A bad flywheel is consistent with not just the noise, but the very noticeable vibration in the cab, and the thing literally sounds like the knock when a piston rod spins a bearing. ( Thankfully, I don't think its a bad rod bearing, I'd hear that all the time, not just intermittently).

So, now I know where to go.

Tom

 

These poeple have the solution, a LUK flywheel and clutch setup. I had one installed in my 97 PSD company truck and the difference is unbelievable. www.carolinaclutch.com www.southbendclutch.com

 

Powerstroker,

I need some more info. Did they use the dual mass flywheels on engines with automatic transmissions? Mine is an auto.

If not, I guess I'm looking at a torque converter.

 

No dual mass flywheels on the autos. If yours is rattling at idle it is more than likely the torque convertor. Sounds like a can of marbles.

 

Hey guy's,
I order a LUK clutch kit and replace the mass flywheel and clutch. And it work's, the rattling went away.
Thank's for all your input. Aloha