67 Fury 440 Stroker Rearend Humming Noise

Hi Everybody,

Before I start this post I want to mention that I also posted this on the ForCBodiesOnly or FCBO forum as well. I’m trying to help out my stepdad here with the rearend in his ‘67 Fury with a 440 stroker and 3.23 sure-grip 8 3/4. The rearend keeps making a humming noise and gets worse the more you drive it at anything over 25mph. The pumpkin was rebuilt 3 times, this past time being built by a race shop next to my stepdads friends shop with new fluid put in each time. New stock tapered axle bearings were also put in too, and the car was jacked up and put in drive to precisely hear where the noise is coming from and nothing was heard. My stepdad is fed up with this car again as he always is, so I figured I would see what everyone else thinks is wrong with it.

Any tips are greatly appreciated.

Thanks in advance.

Have you checked the driveshaft for balance and straightness? Another dumb idea have you checked the exhaust to see if it is hitting anything?

No noise while spinning in the air but but noise when tires are rolling makes me wonder.

Have you swapped out the back tires with completely different tires to see if you have a bad one?

Also make sure the u-joints are not overly tight or binding.

Is the whining sound throttle sensitive?

Does it change on hard left or right turns?

Are they reusing the same gear set?

have you looked elsewhere? A lot of things can make and transmit noise. I'm thinking it's time to look outside the box (pumpkin)
There are some good suggestions above and likely more to follow. Tires might be a good place to start. had one years back that was similar. Drove several around the bend as the tries were new. Iswapped the ones off my 68 and the noise vaporized
keep us posted

No, it’s all new

It is throttle sensitive yes, and we are not sure if it changes when it goes hard left or right no so we will have to take it for another ride and find out

My stepdad says and I quote, “the driveshaft was straight last I knew”, and that the exhaust is not hitting

No

Humming noise would make me want to disassemble (again I know) and check the wear pattern on new gear set.

take out the rear seat and have someone ride [?] back there to see if the noise can be pinpointed.
i have done that several times in the past.
beats having them riding in the trunk when getting stopped by the police.

Please explain rebuilt. New bearings and setup. Or used r & p each time.

It’s my understanding once a gearset is used at a certain setting moving the pattern may result in noise.

If you had it rebuilt twice and the noise hasn't changed, it's time to look elsewhere......

I would take it to another shop next, what ratio is it?
Why does it have an earlier pre1965 rear end in it? 1964 was the last year Mopar used tapered axles in the 8 3/4 rear ends, 1965 and later should have the later style flat flanged axles in it without the tapered axles

He mentioned tapered axles bearings, not tapered shafts.

... and it's 3.23 gear .

No hum off the ground , if it's in the rear that would have me checking the axle bearings , is the endplay set right ?

Axle specialist in my area used to tell me that sometimes just touching the brakes - if the noise diminished and returned after letting off the brakes would be another way to see if the rear wheel bearings were at fault. The drum would “pilot” off the shoes and relieve pressure off the bearings. I just used the hard left and right maneuver to test the bearings.

New everything, even r & p

My stepdad said he set the endplay, with very little movement. He as you said thinks it maybe the axle bearings

You would be correct, thank you

I saw tapered axles and not the bearings, OOPS sorry.
As far as the axle end play it should be more than .001 up to .005, no more than that very, very little
Use the adjuster to set it so you have no end play and then back it out a tiny bit, one notch at a time until you can barely feel the end and out movement of that axle

If you have a whine coming out of a differential what I've run into is improperly set pinion depth. And in the two case I've personally encountered, the noise was different under acceleration versus coast. If loading does not change the noise, I'm with slantzilla, time to look elsewhere.

Another topic posted on Moparts- " What tool did you wait too long to buy....." made me think of the wireless noise isolation-determination device. it has multiple hook ups- like microphones to place in various areas. Then while driving the passenger wearing the headphones listens to each sensor individually. The sensor/channel with the loudest noise is the area at fault.

https://www.ebay.com/itm/314765649390

i will agree with the above adding deceleration to the mix. So, if the noise or pitch changes under any of the 3 conditions it is likely the gear set was not set up correctly. A noise on Decel is indicative of the pinion being to deep. the opposite is true under accel. I am not saying a hard accel or decel but rather a very slight increase either way while cruising on a flat road. Almost like adding or removing a feather from the gas pedal.
I will also comment that the noise would likely not be noticeable with the wheels off the ground as there is no load on the bearings or gears. While the noise is present a Sharp L or R turn will usually identify a bad bearing as you load or unload the bearings while doing so.
keep us posted

Don't be afraid to look elsewhere. Not saying it is elsewhere. But I hunted a drone/hum for 3 years. I changed everything, I'd swear to the man above it was coming from the back driver's side of the car. That's where the sound was. For a reason not related, I changed crank and water pump pullies. Sound totally went away.

you ain't the only one that's chased noises, only to find they were "miles" away from where you thought they were coming from.
that is why i have no hair on the top of my head...............
i see you are in Pittsburgh Jeff.
i'm only 85miles north in Brookville.