My F-250 is intermittantly tugging back for a split second(like the brake is applying itself). What is up?

Question

I have a 2000 diesel F-250 with 95k miles. I was towing a camper, and about 150 miles into the trip, I kept on feeling a brief tug back on the truck once a minute or so - it was very light at first, but then it got harder and the tires actually screeched for a split second a few times. I got off the freeway, pulled over for a few minutes, and got back on the feeder at about 40 mph, and the problem seemed to go away (or maybe I just couldn't feel it anymore at the slower speed).

I was towing a pop-up camper - it is relatively heavy for a pop-up, and it DOES NOT have its own brakes. It didn't seem like the engine was struggling - I was at normal 1800 rpm at 65 mph. It felt like a momentary brake glitch - but I couldn't tell if it was the back or front tires that screeched, so it could have been a temporary transmission glitch.

I have driven about 30 miles without the camper since then, and haven't duplicated the problem yet. Any ideas?

Answer 1

I'd check the wheel bearings on the trailer.
They may be dried, rusty, or locking up.