I've been driving the Trekker for ~200 miles per week lately.

In the last month or so, my brakes will intermittently and randomly make a loud clunking sound from the rear of the truck.

It sounds like it clunks once or twice per revolution of the wheel. I've read other threads about pulsations that feel like ABS kicking in, but I've had ABS and this is much slower of a sound. I have also had warped rotors before, and this is completely different.

The first time it happened, I pulled over immediately because I thought a wheel was going to fall off. I checked torque on the lug nuts, all were tight.

The clunk is actually worse at lower speeds; at high speed, I can barely feel it. When I'm close to a stop, I worry that my rear axle is going to fall out.

The clunk also gets worse if I press harder on the pedal.

I did the rear (drum) brakes a year or two ago and they have been fine until now. I don't believe the amount of driving I've done could have worn the shoes already.

My proportioning valve was removed, as it was causing too many issues in the past. So, that isn't the issue.

Likely going to tear them apart today or tomorrow, just wanted to get a head start on getting opinions from you guys. I'd do it sooner but I already need to replace my front main seal today!

Thanks in advance for any input!