Just recently I've noticed a grinding noise in the Dart at speeds above 45 MPH, when under partial throttle. If I give a little bit more throttle or let up a bit, it goes away. Given this I've figured that it has to be the torque converter grinding due to only being partially engaged.

My truck does the same thing, but it's always done that (and it's a normal thing for Toyota torque converters to grind/rumble at high speeds under partial throttle); BUT the Dart just started doing it. Should I be worried, and is it possible that it could be anything other than the torque converter?
I'm so used to it being normal in my truck that I'm not sure if I should be overly concerned about it or not with the Dart. It's recently had the tranny fluid changed, but no new filter. Hoping to change the filter this weekend.

Thoughts, guys?

_________________
'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

Is your TC a lockup converter? Maybe it is not locking up properly.

Have you changed your axels? A chevy truck I drove once made a wierd noise too at highway speeds, it ended up being that the rear end was not perfectly centered. It was just a job of taking it to be centered at a shop.

_________________
If it ain't broke, I haven't started "fixing" it yet.

To be honest, I'm not sure. I just know it's factory stock in a '70 Dart Swinger with an A904.
Same axle too. The dinky little 7 1/4" (I think). Either way, I know it ain't one of the good 8 3/4" axles

_________________
'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

Check your rear axle bearings. They will make grinding noises when they go bad.

_________________
Official Cookie and Mater Tormentor.

But wouldn't that be strictly speed related? I only get the grinding at partial throttle. Ease up or give 'er some more and the grinding goes away.

_________________
'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me