Hawk rear noise

[valleyguy]

I know noises are hard to diagnose; hopefully I can get some guidance; I have a noise coming from the rear of my Hawk, almost
like a grinding type noise, not a high squeal; the car has only been driven in the neighborhood, not over 35mph, so I am not sure if the noise would get worse at higher speeds. (Dana 44, not twin traction.)

I thought it was the rear wheel bearings but they have just been changed along with new shoes and wheel cylinder in the rear.
I have not changed the universal joints and there does seems to be some slop there. If it is not the universal joints, then I guess I have a more major problem with rear differential itself.

Any thoughts?
Thanks much,

Joe D.

[Bud]

I would think that the differential is making noise if you have replaced the wheel bearings and they have been adjusted properly per the instructions in the shop manual. Does the differential have enough lube in it? Also check the lube for metal flakes as that would indicate a failure of one or more bearings or possibly the ring and pinion gears. U-joints usually make a clicking noise when they are ready to fail, but they can set up a vibration when they get worn as the trunions get rough where the needle bearings touch them. Bud

[valleyguy]

The Rear diff is full, I just replaced the rear pinion seal and
re-lubed. I first noticed the leaking seal when I bought the car many moons ago; Since then, the car hasn't been driven much, as I said. Its possible that the previous owner ran it with little or no fluid, I don't know. Guess there is no easy way to isolate the noise - bearings vs the ring and pinion. Maybe just shop for another rear... Thanks,

Joe D.

[Dan Timberlake]

I'd run the car in gear on a lift and "listen" to different areas of the rear axle with a screwdriver or hose as a stethoscope.

http://www.multisurfacemotorcycling.com/Images/lever_adj/images/IMG_0916.jpg

http://image.truckinweb.com/f/8120045/0613tr_06_z+101_garage_tech+stethoscope.jpg

I ran a Ford rear axle real low on oil to the point the gear teeth were microwelding or seizing together at highway speed. On the gas, bang-bang-bang like an exhaust backfire. The gas station beside the highway did not have any gear oil so we filled the HOT rear axle up with motor oil and drove home. Refilled with gear oil and drove the car for several more years. Only symptom was It howled quietly at some mph and throttle settings.

[valleyguy]

Dan, thanks - good tip. Up to now I didn't have that option
since the car was not registered or tagged for the street.
Now it is, (as of today). Hate to buy another rear if this one
can be fixed at a reasonble price.

Joe Diggle