Originally Posted by ShrimpBurrito
I just did an overhaul on the TM wheels --- new brake assemblies (new shoes, magnets, springs, backing plate, everything), new drums, new bearings, races, and seals, and hand packed bearings with Castrol wheel bearing grease. Soldered the wires....one old wire nut connection was down to a few strands, and one wire going from one wheel to the other was very badly corroded.
After reassembly, I adjusted the brakes with the adjusting wheel so that I could barely turn the wheel, and then backed off until they were just dragging a bit. When I spun the wheel, I could hear brake drag for the entire revolution, but the wheel spins fairly freely with one hand, but definitely not as freely as with no drag. (which is what the Dexter instructions say to do -- adjust to a "light lining drag", whatever that means)
Then I went for about a 7-mile test ride, braking frequently, both at intersections, and manually braking the trailer via the controller while en route. When I got to my destination, both hubs were very hot (could only touch them for 1-2 seconds before getting very uncomfortable) and I could smell brakes.
So it seemed the brakes were too tight. I jacked up both wheels and adjusted the brakes to be less tight. So now when I spin the wheel, you can hear drag for part of the revolution, seemingly indicating a high spot on the shoes. I let the hubs cool off for about 30 min, then drove 3 miles. The hubs heated up again, but not as bad. After letting the hubs cool for about 90 min, I then drove the same 3 miles in reverse. The hubs got warm, but not hot -- about the temp as what they've been over the many thousands of miles we've traveled with the TM.
But then I drove back the 7 mile trip again, braking more than the previous 3 miles, but not as much as the first time doing the 7 miles. At the end of that trip, the hubs were again very hot and I could smell brakes, although probably not quite as bad or smelly, but still obviously too much of both.
So it seems my brakes are still dragging too much. I haven't touched the adjustment on my controller. I was going to lower the voltage and go from there, but first decided to wear them in first. But even at the controller's current setting (which is the maximum voltage on the Prodigy P3 controller), and after about 20 miles with new brakes, the wheels still don't come close to locking up during a hard stop. So I don't think the controller is set too high. And according to the controller display, there is no voltage going to the brakes while underway.
I don't think it's the bearings generating the heat because a) I smell brakes; b) the hubs seem to get hotter when I brake more; and c) I can't think of anything I could have done wrong installing the bearings. It was the first time I've changed the races, but not the first time I've repacked bearings. I tightened the castle nut tight, then backed off about a 1/4 turn....it's on there a little bit tighter than hand tight. The races are fully seated.
I think I'm just going to keep backing off the brake adjustment until I'm not generating heat, hoping I don't superheat the brake shoes or smoke the bearings in the process.
Any suggestions?
Dave
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