Rear noise HELP

[318Fred]

Can you please help me with a noisy rear axel
I have a 72 plymouth Satellite with an 8 3/4 3.23 open
I seemed like someyhing happened over night ??
The rear was very quiet. I started the car in the
morning and when I drove it, the rear now make
a heavy harmonic humming/rubbing sound. It starts at 20 mph and increases
as the mph increases.
It is consistant with speed and does not differ from
accelleration decelleration or cornering. If I break hard it quits ??
It was very quiet the night before. I don't think I ran over any Chebbies

So Far

I have check all the bearings, Ujoints and driveshaft for straightness
Yesterday I replaced the center section with another one from
a wrecker. 3 hours later ( replace carrier ) STILL THE SAME NOISE
It's almost like something is rubbing cousing the humming . Tires were checked.


Fred..

[rumblefish360]

Now your down to axle staightness. Did the rear shift? Worn suspension parts. Nose of carrier in the right position?

[PRO]

Sounds like an axle bearing going dry,do this test if you DONT have a posi,jack up one rear tire,start the car and put it in gear,carefully accelerate the engine(keep your left foot very near the brake pedal)then do the other side,the axle that isnt spinning when you dont have the noise is the culprit.Be sure to hand pack a new axle bearing with a superior grade of grease after its been pressed on............PRO.....

[318Fred]

Thanks for the replys Rumblefish360 and PRO
The axel is straight and did not move
I jacked the car up a side at a time.
The rear makes a very low howl only with the right tire up
and no howling or vibration with the left tire up.
But the noise is MUCH less with the car tires up
How about carrier bearings ??
OR A bum carrier from the wreckers ??

Fred..

[rumblefish360]

I can only think of 2 other things and I don't think they will apply...low oil and/or worn gears. From the been there done that (and got burned) desk. This what has happened to me. No oil in the rear burn out my gears. The wine was bad ( i was young and stupid)

[Hammer 74]

You have to remember that when you had the tire off the ground and it was spinning there was no load from the weight of the car on it. I think PRO is correct and you found the problem in the side that was noisy. I have seen bearings in machines that were noisy when under working loads but quiet when freewheeling/ no load. I would pull that axle and check the bearing for wear.

[318Fred]

Sounds like I should pull the axels and replace the bearings.
At least I will have new bearings.
The crown and pinion look good with no worn edges on either
If the noise is still there plan 2. Should I try Carrier bearings ??
A local mopar mechanic can do it . He will get back to me with a parts and labour cost
The guy I bought the 2nd carrier is willing to give me a full refund

GAD I just got the price of a 8 3/4 rebuild kit. (All seals and bearings )
$ 130.00
Now the plan is for bearings and another carrier from the wreckers
The rear is also getting noisier

Fred..

[Dartasaurus]

For Gods sake use Hypoid oil.