Driveline vibration origin.

[LeftHander]

I recently discovered an odd source of a driveline vibration in my '96 Ranger supercab. Shakes at freeway speeds. Replaced the center bearing carrier assembly. No joy. Had the driveshaft assembly checked at the driveline shop. All good. Discovered that BOTH axle shafts were bent ('96 had a soft alloy shaft). Replaced them with Rock Auto shafts. Still shakes. Replaced the rear axle assembly with a junkyard unit, thinking there has to be something out of balance inside. Still bad. Jacked it up and set the axle on stands, took the wheels off, put it in high gear at an idle, and looked at the driveshaft. Looks and feels (sanding block against shaft) okay, but still can feel a shake. Crawl out and see the drum spinning, and realize it's not round (concentric) on the outside! Turns out the Chinese are making brake drums using a manufacturing process that has a step that must be done very precisely to avoid needing to machine the outside. They are welding (not sure which process they are using) the flat faceplate to the drum without ensuring it is centered. The inside is finished afterwards, but the drum now has a variable thickness since the inside and outside are no longer concentric. That is a LOT of metal mass spinning off center. Sometimes they weld balance weights to the edge of the faceplate, but that is seldom enough weight to compensate. What is usually noticeable is a machined edge inside the drum at the edge of the plate. If that is even all around, it's probably a good drum. If that width varies enough to see, it's junk. Every drum brand I have looked at in person, or photos on the web (rock auto), show the same type of welding assembly. Half a dozen+ brands all the same.

 

[rusty ol ranger]

I recently discovered an odd source of a driveline vibration in my '96 Ranger supercab.

Could be anything from a u joint to a bad input bearing....more info would be helpful

 

[LeftHander]

I suspect that these offset drums would exceed the minimum metal thinkness spec when worn down to the limits of the inside diameter. I think that is a federal violation.

 

[LeftHander]

Could be anything from a u joint to a bad input bearing....more info would be helpful

It posted in the middle of typing...

 

[Josh B]

We wanted Cheap, and Cheap is what we got :/

If there was a major trade war now we wouldn't stand a chance, there are not enough machines left here to do much with. I think they also scrapped all those and sent them to China, and China is setting on it all while building war ships and submarines, while our government is sending them money to pay for OUR pollution, why? Because they claim to still be a "developing country" :/

Cheers!