Whomp Whomp Whomp noise?

[Tony 69]

Hi members. I’m sure describing a noise on a post isn’t going to go to well but I will try anyway. I have a whomp whomp noise between 60-80. It doesn’t change “that much” whether on/off the throttle. But it gets loud and very rhythmic. Almost sounds like something is going to break. There is no vibration, just whomp whomp whomp. As far as I can tell everything is tight. New u joints and a yoke too that was worn out. No tail shaft seal leaking. Can my engine cause this? I have an oe balancer but don’t know about the internals of the engine. I see some 440 were externally balanced and some not.
Should I try a fluidamper balancer. It’s an expensive guess. Unfortunately the noise kinda fills the car so I’m not sure where it’s coming from. Thanks for your suggestions.

 

[Tony 69]

Oh yea, 69 Road Runner 440/727 and 355 8 3/4 suregrip

 

[RemCharger]

Double check the u joint install.
Some people leave the clips out.
Bad no-no.

 

[kiwigtx]

Check the trunk ....might be a Stooge hiding in the rear.

 

[khryslerkid]

 

[khryslerkid]

Seriously, maybe a tire starting to separate?

 

[Tony 69]

Hmm I guess that is possible
Wouldn’t I feel a vibration?
And I will double check the u joint

 

[RemCharger]

Seriously, maybe a tire starting to separate?

Now there's a likely bingo.
Spin the tires, check the dates. There will be some coding by the dot number

 

[khryslerkid]

Hmm I guess that is possible
Wouldn’t I feel a vibration?
And I will double check the u joint

A tire separating on the inside will make the noise you're describing. Do like RemCharger said. Look at the tread when rotating also to see if they're running straight. Terrible consequences if one flies apart when doing high speeds. There's been members on here that lost their quarter panels, fenders and worse.

Last time I was in your neck of the woods, 60 - 80 would have gotten me a big ole ticket!

 

[kiwigtx]

Seriously, maybe a tire starting to separate?

....or a flat spot.

 

[eldubb440]

Seriously, maybe a tire starting to separate?

could be Italian tires......... when dego flat, dego wop wop wop........ I'd like to hear Mario's spin on it @MarPar

 

[PlymCrazy]

Besides the sound can you feel it anywhere? Steering wheel? Floor? Gas pedal?

 

[Tony 69]

No. I cannot feel the sound anywhere. Originally I had a vibration which was a yoke and they straightened and balanced the drive shaft. Vibration gone. Now just the sound. And (before everyone goes nuts) the ties are old. Embarrassing 2011. The car sat a long time. They were next on my list, maybe a radial M/T sportsman if I remember right. I wanted to burn these off first. They are 255/60/15 BF. According to the tire calculator they are a 27” tire. I’ve put it off trying to decide on a tire size. 27 or 28?

 

[Tony 69]

Off subject but I have to show you all this too. WOW! Merry Christmas. Today at Walmart.

 

[MIKESPOLARA]

10 yr old tires,

 

[ruffcut]

When looking at new tires, with the 3:55 gears, consider a taller tire. I have the same gear ratio and 29 inch tall tires.
As for the noise you described, in the speed mentioned, I believe there are certain harmonics which could be causing the problem. JMTC!

 

[Cranky]

Seriously, maybe a tire starting to separate?

That thought came to mind too but at the speed he's talking about, it would be really fast wop wop wop

No. I cannot feel the sound anywhere. Originally I had a vibration which was a yoke and they straightened and balanced the drive shaft. Vibration gone. Now just the sound. And (before everyone goes nuts) the ties are old. Embarrassing 2011. The car sat a long time. They were next on my list, maybe a radial M/T sportsman if I remember right. I wanted to burn these off first. They are 255/60/15 BF. According to the tire calculator they are a 27” tire. I’ve put it off trying to decide on a tire size. 27 or 28?

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The BFG's on my diesel are from 06!! Yeah, I don't drive it very fast with them but so far, they ain't wopping. I would for sure jack up the car and roll the tires and see if you can find any high spots in the tread. Been down that road many times and with tires that were much newer. I HATE steel belted tires!

 

[Big Bad Dad]

With the driveshaft and yoke issues you mentioned, I would advise to check the tailshaft bushing in the transmission. If you previously had a worn out yoke, and out of balance driveshaft, that bushing probably took a beating. And if it is worn and sloppy, your driveshaft will "flop around" a little bit....

 

[Tony 69]

I did consider the tail shaft bushing. It moves up and down a little but I can’t measure it. And no leak so….I think tires first since they are due anyway and a safety issue. If the drive shaft turns at x speed in first, x speed in second, and x speed in third, shouldn’t I hear this at all speeds?

 

[Cranky]

I did consider the tail shaft bushing. It moves up and down a little but I can’t measure it. And no leak so….I think tires first since they are due anyway and a safety issue. If the drive shaft turns at x speed in first, x speed in second, and x speed in third, shouldn’t I hear this at all speeds?

The rear end dictates how fast the driveshaft spins. Of course it changes rpm as the car speeds up but the transmission doesn't change DS speed.