Hey, new guy here. I don't have a Ranger or B-Series, but I do have Ford's older B-Series counterpart. 1979 Ford Courier, 2.3L/5-spd. I have had a bad rear end shake since I bought the truck nearly three years ago, so I'm sure it existed well before then. It only happens around 60-65 mph, and there is also a kind of buzzing/humming sound whenever I'm coasting to a stop in neutral. I have:

• Replaced and balanced the tires several times
• Rotated the tires several times
• Replaced all four wheel bearings
• Replaced steering linkage
• Replaced front suspension
• Balanced driveshaft twice
• Replaced driveshaft center bearing
• Replaced all three U-joints
• Checked rear wheel lateral and radial runout
• Had the front end aligned three or four times
• Checked engine and trans. mounts

And yet the issue persists. Any opinions or help would be greatly appreciated as I am stumped and this problem is driving me bonkers!

 

Are the U joints parallel?

 

As in are they phased? I'm sure they are, because I got the truck up on stands and had my wife run it at 60, and the driveshaft wasn't vibrating or buzzing or anything like that. I forgot to mention that when I was doing this the driver's side rear wheel was vibrating rather loudly, and the vibration was definitely visible. The other wheel wasn't vibrating at all. I also seem to remember checking the pinion for play but getting none.

 

Is it possible for the rear drum to be warped or out of balance?

 

Probably not out of balance. It didn't seem to have any runout, either. I did take those drums off of another truck shortly after I bought it. It had the shake before and after I did this.

 

Bent or off balance rear axle?

 

That's kind of what I was thinking. Either that or the diff., but I would definitely hope the axle instead of the diff.