I previously had written to get feed back on locking up of brakes on my 1939 plymouth.? I had all the brake hoses replaced, return springs and wheel cylinders done.? Problem solved. Now when I drive the car at a speed of 10 miles per hour or more, I hear a clanking sound from the rear. Any ideals what that could be? When I backup in my drive way or turn around, I don't hear the sound.? I checked and put grease in the rear axle.? We pulled each wheel to see if the shoes or parts were loose, but nothing.? This started after I had brake work done on the car.
My first guess is that the universal joints are bad. At two separate times our 38 made a clanking sound too - but only at certain speeds. We removed the drive shaft and inspected the front and rear u-joints.
The first time the front u-joint had a worn part.
The first time I took the drive shaft to a shop and had them replace the faulty parts.
The second time (5 years later) the rear u-joint was worn. This time I bought my own shop press and did it myself (much more fun).
Both times, replacing that part did the trick and the car runs very quietly now.
To replace the worn parts we used a shop press to press out the pin. Then you can remove the housing and interior parts. Be careful handling the tiny roller bearings (they look like small cylinders) It's easy to drop one on the floor and then lose it. Then you get to buy a whole new set (experience).
Hope this helps.