Rear End Noise

[nola_born]

After driving my '64 for 20 or more minutes,
whenever I turn, I hear a "rubbing" or "groaning" kind
of noise coming from the rear of the car. When the car
straigtens out, the noise stops. I also notice
that it's easier to hear when turning from a standstill (no
surprise there I guess). When coasting around a turn, I
still hear it, but not as much. I also notice that
it's considerably louder when I turn to go up a hill
or into a driveway.

Anyone have an idea what might be causing
this noise??

I've had the car looked at and everything checks out ok.

Thanks in advance

 

[Eric]

Welcome aboard nola!

My first reaction whenever someone mentions a rear end noise that occurs when turning is that you are low on fluid in the differential. However, that noise has been called many things from chattering, to clicking, to popping, but never groaning or rubbing.

The fact that the noise only occurs after the car has been driven a little tells me that heat is playing a part.

This leads me to believe that you may have a shoe that isn't retracting properly and is rubbing the drum and/or you have a drum that is warped ever so slightly and the heat is making it more pronounced. I'm assuming you still have rear drums. If you've converted to rear disks, then it still may be the shoe but in the parking brake assembly.

Hopefully some of our early mid-year guys and gals will pop in with more suggestions soon.

 

[Subfixer]

Sounds like a wheel bearing starting to go.

 

[JohnZ]

Classic symptoms of "chattering" Positraction clutch plates, especially when turning from a standstill. Someone either put the wrong lube in the diff or didn't add the required GM Positraction additive (4 oz. bottle, P/N 1052358). Go to your Chevy dealer and get two quarts of GM Positraction lube and two bottles of the additive; get a suction gun and suck out all the existing lube you can, add 1-1/2 bottles of the additive, and then add the GM Positraction lube to the bottom of the fill hole.

Then drive to a large parking lot and do a series of slow figure 8's to get the new lube/additive inbetween the Posi clutch plates, and drive it around town. If it still chatters after a few miles, repeat the figure 8 routine again. If it still chatters, you're probably due for a Posi unit rebuild.

 

[nola_born]

Thanks to everyone for the replies...I'll try the fluid change and post results.

Thanks Again!!!

 

[nola_born]

Had the fluid changed and the noise is GONE!!!

Thanks again for the advice everyone!!!

Rick