I have been driving this car for a few days. Today on my way to work, I started hearing loud clunking noises from the rear passenger side. I pulled over, and checked to make sure the lugs were tight. They were. I drove it another 20 feet still with the clunking. I came back to it after work and the tire was flat. It must have been a slow leak. I didnt notice pressure loss when I was checking the lugs. This clunking was felt through the car. I am going to get the tire repaired in the morning. I need a few things to look for when I go to fix it

Eric in Montana

The brakes, maybe? Does the '79 have rear disc? Make sure the brake line isn't boogered up. Could also be a bad wheel. Shake the strut towers to make sure it's not loose. That's a few things. Good luck.

Check your u-joints to make sure they are not excessively worn and that all of the bolts are on and tight.

i took the tire to a repair shop, and the tech said it had seperated. i put the new tire on and drove it with no issues. thanks for your help guys!