Jakerx

awesome thread cool info

Manning

Yeah, I was blown away when I read it, really interesting reading. He really caught hell from a bunch of the other lister about it though. Actually I wish he would post to this BBS, but I have never seen him do so.

faithless

Why not start making the bearings smaller, and puting a sufficient insulator around the outer race?

ErichCS

Interesting info, as others have said its not something i would have thought to to be true before reading some off the information he provided. You gotta love the basics of EE. So what's is the take home message here? Is there something we can do to prevent this from happening? Are some of the wheel bearing failures in the 944's due to this perhaps?

I'm sure nobody is going to have answers to these questions, but its something to think about...
Manning - Thanks for the info!
-Erich

Porsche-O-Phile

Made me a believer. Interesting stuff. . .

Dmitry S.

We were actually taught this stuff in my automotive technology class. Most of the the time, when the Engine to Chassis ground is missing from some reinstalling an engine incorrectly, the electricity does flow through the wheel bearings. Think about it, the engine and transmission are only supported by rubber mount to the chassis. The electricity is forced to travel from the engine/flywheel, down the torque tube, through the transmission, out the CVs, and into the wheel bearings.

IceShark

Busses used to always have a strap to the ground/street. I'm not sure what they were made of to take the constant abrasive duty and how fast they would wear out. And they were city busses not going that fast so the strap wouldn't go aero and lift off the ground. Perhaps it would be a good idea to put one on.

Chris_924s

I'm calling Sid Viscous. He'd LOVE this!!

Interesting read.

Legoland951

An extreme case of bad ground, when I tried to start a car, the rear steel brake line caught on fire (from the liner inside the braided steel) because of the heat from GROUNDING THROUGH THE STEEL BRAID to the torsion bar housing. The fire travelled up and almost got to the plastic gas tank. That would have burnt my house down. I had pictures of the brake line along with leaking fluid on the ground in a previous post.

Rock

He has to be right! I believe him 100 percent. My car is proof.

The thing had trashed ground, and was an electrical mess. That current had to be going somewhere. Then! Behold! Both my wheel bearings failed! Woo woO!

bader$

Ive seen it happen with Clutch cables why not bearings.

Bret08

I have static on my stock AM radio but I have a 2007 GMC Sierra 4x4, not a Ford. Could it be from the rear wheel bearings? And would the ground straps help or is it something else?

Chalt

I have been reading a bit about this after I came across this thread. Some of the links don't work anymore so I was googling and reading. You can still buy the ground straps. Amazon and others have them. From what I read, they touch the ground when you come to a stop but not touching when you are at highway speed. There are two instances I read about where people use them.

1) people trying to reduce getting shocked when they touch the car from static electricity. Some people said the straps were effective and some said they weren't.
2) people who work in welding or under High Voltage power lines >250Kv. They said you get induced voltage if your truck sits under power lines (>250Kv) and it will shock the hell out of you when you touch the truck. Welders and others who work in the oilfield - some said it's a requirement (per the oilfied company) to have a ground strap.
I didn't find anyone who said they were using a ground strap for static electricity generated by the wheel bearings.

I did read that having a poor ground from chassis to engine or poor chassis to battery will cause the electricity to try to find the path of least resistance which will mess things up. I found some people suggesting to ground the transmission to chassis, the suspension, and even the wheel hub to chassis, though I'm not sure how you ground a wheel hub. I even read that some people believe insufficient ground can ruin a transmission.

Then people said that tires are an insulator while others argued they are a poor conductor (metal in the tires and carbon black). They argued that electricity can ground through the tires.

So I am left thinking what additional grounds would be good prevention on our cars. I don't know if 944s eat wheel bearings often.

Van

Holy old thread!

When I was a kid, my mother had a Mazda Protege that always gave you a static electric shock when you closed the door after getting out. She got the rubber "grounding straps" that dragged behind the car... no difference. We just lived with it.