Technical ever see an arm bushing grounded?

just found this while apart for new bushings, why?

 

That's a first for me... not sure about that one.

 

Wouldn't the inner sleeve do the same thing?

 

Safety wired.

 

Not a ground. That's a safety wire.

 

Now that's...funny..a safety wire.!?
That would never work as any semblance of safety wire.

Maybe the guy that did this worked in the Aerospace industry. EVERYTHING is grounded, some parts are redundant grounded.

Mike

 

Right.

 

I don't think so. The metal inner sleeve of the bushing is in contact with the A arm shaft and the bolt on the end. Rubber separates the inner sleeve/inner shaft from the A arm itself, with no metal to metal contact. If that were not the case, the rubber would not isolate the the road shocks as intended. The construction of the strap is that of an electrical ground strap. If it was intended to be a safety wire, it would have to prevent the end bolt from turning. It would not as configured. Safe tied bolts have drilled heads for the safety wire to positively prevent the bolt from turning.

As for what the installer had in mind by grounding the components, we'd need to ask him.

Ray

 

^^^^^ Your right.

 

It was factory on some model of vehicle as I have replaced the bushing on at least one of them. No doubt the engineer that came up with it had a reason for installing it.

 

Was it off topic?

 

Dodge Omni had that problem. Electrical current was seeking a ground through the wheel bearing.

 

I don't believe so but that was around 1972 or 3 and I remember dealing with the ground strap but can't remember the car. When you have to stop and take a couple of extra steps in the process it sticks in the back of your brain. I did front end and brake work in a Firestone tire company store then and we often got cars that no one else wanted to work on.

 

Technically, that is a bonding strap, not a ground strap. Bonding is done to ensure that the parts are electrically continuous. In a vehicle application, it's usually done to eliminate static electricity that can interfere with radios, or if the car is newer, electronics. If you've ever pulled a front wheel bearing dust cap and found a spring with a contact that rubbed on the end of the spindle, it's the same concept...

 

Steve, while I enjoy reading your informed comments on many items, and I do not disagree with your analysis here, the words 'grounding' and 'bonding' are, I think, a "distinction without a difference"......or am I missing something?

 

I was pretty sure the one I saw was originally intended to combat static electricity. If I'm not mistaken there is some model that the strap runs from the A arm to the frame

 

I can see that happening as well. Black magic is funny that way.

 

thanks for the reply's, yes this is a first for me, its a 67 caddy

 

There's a webpage somewhere that I'm too lazy to dig up, that talked about really weird stuff that stray electrical currents and static can do. Grounding is really important, but also bonding, fleet owners were some of the end users that figured out some of it. One, because it costs a lot of money to run a fleet so they notice,l trends, because odd things happening in only a small number of otherwise identical vehicles. One was as I recall some kind of static electricity buildup that started in the differential or d/s or somewhere like that and somehow caused trouble with the transmission or some damn thing. Really off the wall stuff. Stray electrical current through radiators/coolant can cause real $$ problems, and yeah pitted wheel bearing surfaces causing early failure due to faulty grounding or stray current.

 

Well, yes and no... LOL. This is my training showing here. In AC electrical, you have three wires that all originate at the same place, the system ground; the neutral, grounds, and bonds. But each one has a distinctly different purpose, and trying to use one for another can cause some pretty bizarre issues if not being outright dangerous. A neutral is a current-carrying conductor connected to ground at the main point of service entry. A ground is a emergency-only conductor that offer a secondary ground path, connecting to the same place. A bond is for connecting any generally metal items that may represent a 'difference of potential' with one of the other conductors to eliminate that 'difference', such as metal water or gas pipes or if a piece of gear has a flexible connection. My favorite one was the neighbor who showed up at my door on a Sunday to ask if I'd please come look at his pump house. To make a long story short, a 'friend' who claimed electrical knowledge installed a light in his pump house but connected one side to the ground, not the neutral. When he turned on the light, it put 90 volts across the kitchen sink while his wife was washing dishes. She was not happy to say the least... LOL. Two issues here; one, the light applied current/voltage to the ground wire (first no-no) and the plumbing wasn't bonded (second no-no). Or another one with the 'hot' shower drain grill, when all the waste plumbing was plastic... Electricity can be funny stuff....

In a vehicle, you only have two 'wires'; the 12V hot and 'ground'. Now, the 'ground' is a current-carrying conductor, whether it's a wire or part of the metal structure. So any wire you install that allows current flow is a 'ground', such as a ground strap between the frame/body, frame/engine, etc. If it's just there to eliminate any difference of potential, it's a bond....

 

^^^^^Steve....Thank you for that explanation...... I now see that "grounding" and "bonding" are a distinction with some difference....potentially

 

Exactly!!!! LOLOL!!!

 

Electricity thru vehicles is interesting. The way engineers designed ways to get around perceived problems.

On a side note of weird auto electronics, years ago I met the man who designed the ball on top of the radio antenna on cars.

 

Actually, after thinking about this more, I can give a more relevant explanation. If you look at a wiring diagram for any '60s/70s Ford alternator, it'll show the various wires and where they go. It also shows that the alternator is grounded, as is the regulator housing. Some drawings show a wire between the two ground points, some don't; all the Fords I ever worked on had this wire. Now, if both points are grounded, why do you need a wire between them? Because the ground path between the two grounded points is longer than the wires, with multiple 'joints'. The alternator ground has to go through the engine block, somehow has to get back to the body structure, and then past the fasteners attaching the regulator to the body, not including any joints that may be in the body structure. Any losses along the way will 'confuse' the regulator because you now have a 'difference of potential'; the regulator checks voltage output by measuring to ground. So 'bonding' those two points will eliminate that difference and allow the regulator to function normally. Theoretically, you shouldn't need that wire but Ford installs it as a preventive measure. It's a 'bonding' wire in every sense of the term.

 

Whatever happened to those I think aftermarket grounding straps that were fitted between the body /chassis and dangled on the ground. A 70's thing, well certainly here in the UK. I think they were sold as an anti carsickness thing as well as trying to prevent static shock. Funny though, I've had a few of those shocks over the years, typically when getting out of a car, but don't recall this occurring for many years now, and I've never had one of those straps! All rather OT though.

Chris

 

They did seem to work to stop travel sickness. My Dad fitted one because my sister would get sick going to Kwiksave. She stopped once the strap was fitted - maybe a coincidence, maybe not


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When I was a kid in the ‘50s I noticed that may heavy trucks, and most commonly ‘tankers’ had a strap dangling front the trailer to the ground. Fairly often it was a piece chain. I was told, when I asked ‘why’, that they were ‘ground straps’ to prevent some electrical shock related disaster.

Funny thing though, the chains used to skip along the pavement and make visible sparks. I thought that would have been exactly what you wouldn’t want under a tanker!

 

Steve,

Excellent example to illustrate the finer point of the difference. Thanks again for taking the time and effort to respond with the details that clarify the matter.

Ray

 

In the local car factory we added lots of extra grounds to the bodies of the COPO cars. Hood deck lid body to frame. Used to help with static for the radios and lights mounted on the bodies.

 

Next time you catch a flight, have a look at the long wire that connects the tanker to the grounding point, which must be connected before re-fueling. (the tarmac is not the best place to have a nice big static spark make an appearance!)