Hey everyone, so I just swapped out my rear end and drive shaft and put the stock rear gears and a brand new drive shaft. (71RR 727 Auto, 7290). The car runs great put when I hit around 75 mph, I hear this faint then strong ringing sound. Nearly identical to the sound a finger makes when traced around a rim of a glass. When I lift the gas, it stops. I can't figure out where the noise is coming from. I'm thinking the rear. Any help would be appreciated.

Used gears? Tough to set back up to the original pattern they were before... Very well could be that.

Did you set up a new chunk or just swap it out?

Check the pinion seal shield. If it has one it can get bent easily and rub the housing which will cause the drive shaft to amplify a ringing sound.

I'm thinking classic ring/pinion issue.

I think it might be the ring/pinion.

Is this something that is serious in nature if left not cared for?

Its sounds dumb now, but I literally swapped out the drag end that was on the car and put the stock one that I had in a crate back on the car.

It sounds like you just swapped the center section, am I correct? Do you remember if the rear end made any noise when it was in the car before? I'm only asking because if you're like me, memory has a way of forgetting things! Is there any noise at all at lower speeds or is it only at freeway speed?

So the car had low end Richmond gears. All I did was swap out that rear for the stock gear. The drag gears never made a noise when it was in the car before. I put in a brand new 7290 axel yoke kit and a brand new drive shaft that went right into the transmission. Everything installed perfectly. Around 30-40 mph you start to hear a whine that disappears around 70mph. That's when the ringing sound happens. It will go away and come again every 30 seconds or so. Once I back off the gas a bit, it goes away.

If you swapped the pinion yoke did you retorque it and check the back lash.

No I didn't

You didn't swap pinions or you didn't check it?

You are NOT providing enough info. Nobody knows what you actually did to the car.

Did you take apart the center section? Meaning did you separate the ring gear FROM the pinion gear?

What rearend is it? 8 3/4? Dana 60? something else. Did you change the WHOLE thing? brake drum to brake drum? Or remove ONLY the ring gear and pinion gear, and reinstall the stock 2 gears? Sounds like you removed the RING GEAR and PINION GEAR and didn't re-set the backlash, and didn't re-torque the pinion nut.

8 3/4 rear end. I changed the whole thing. Brake drum to brake drum.

Did you do anything with/to the pinion gear nut on the rearend that you put it? Anything to the ring gear? Did you take out the pig at all?

It's like trying to pull teeth with some people, they want help but won't give out any useful info.

I'm sorry, I'm not an expert with rear ends. No need to be like that. I sincerely appreciate the help from everybody here.

No, I didn't touch the anything in the stock rear end. Didn't touch the ring gear. I literally bought a new 7290 axle yoke kit from Year One and a drive shaft and took the original rear end that came with the car when I bought it, the stock gears and assembled. I probably sound like an idiot, but I'm just trying to learn.

That's how you learn, by doing it, and asking about it. So you installed the yoke kit, but didn't torque the pinion nut when you installed it. How tight did you get the pinion nut? Very tight, VERY tight, or sorta tight?

And that axle yoke kit, is that a yoke and u-joint, or just the two sized u-joint?