[FrostOne]

My F-350 7.3 automatic has made a "bag of pebbles" noise for quite some time. The noise is present in neutral and park (unloaded), but stop when you put it in drive or reverse (as you apply load) If your listening hard you can hear it as you back off the throttle while driving.

No real shifting issue with the possible exception of tough to get it into overdrive while towing (16k). At 70, on the flat highway while towing we're close to 3k RPM, but have to back off the throttle to get OD to catch.

Fluid looks and smells fine. We'll be pulling the pan thursday to look for chunks. Any suggestions, course of action, ideas? We'll be towing 4,000 w/ livestock in a 4 weeks and I'd like to feel OK about it.

Thx

 

[woodnthings8]

The "can of marbles" sound is pretty common for the early SD trucks. It is common to the torque converter and can be fixed by installing a new converter.

 

[FrostOne]

The "can of marbles" sound is pretty common for the early SD trucks. It is common to the torque converter and can be fixed by installing a new converter.

That's what I understood with the stock converters, but the this truck has a Sun Coast converter (or is supposed to) and that's throwing me a little. I understand anything can fail, maybe I'm in denial, but I'd hate to replace the Sun Coast with an inferior converter and have it not solve the problem? Is there a reasonable way to test / diagnose the TC? I've also heard the while the "bag of marbles" is common, they'll also "run forever" albeit the noise is annoying.

If I do have to replace the converter, any recommendations on brands?

Thank you

 

[rammertide07]

I've heard brake-tourqing can diagnose a bad tc if you got a shudder in it. Probably wouldn't help though in your case.

I have a BD and it holds up very well. I've heard good things about ATS tc's....not the transmission.