Hey all,


Today, I was walking up to my Cat (X300, Straight Six, Non Supercharged, VDP) and I noticed something hanging beneath it - it seems to be a piece of aircraft cable kinda dangling around the front driver's side wheel. (I attached a not so good photo of it) - looking on the passenger side, there is another piece of cable, and it looks like its attached, so I imagine I have to fix it.

Does anyone know what that cable is for exactly? Any information would be great!

Thank you!

 

It is some kind of earthing strap for the front calipers. I have to say that I don't really understand what it's purpose is. I don't have the cable on my car and I don't have any issues. You obviously don't have the cable and and don't have any issues. So don't worry about it. Put it in the bin.

 

Yeah, I just noticed it, so it could be a new "injury" or an old one, either way, as you say, I've had no issue driving it - thanks for getting back to me so promptly. I wonder why they'd put a ground wire there? A little strange, but I guess old saying holds true: "There is no excellent beauty that hath not some strangeness in the proportion."

Thank you again!

Ash

 

Hi Ash,

Those braided cables are ground/earth straps that help protect the wheel bearings from erosion due to electrical currents and static electric accumulation and discharge.

See pdf page 21 of this document:

Timken Bearing Damage Analysis

Probably a good idea to repair your ground straps.

Cheers,

Don

 

Don B, interesting read about bearings on that Timken site.

 

Thanks for that info Don. I've never heard of that before.

But I have to say that damage to the wheel bearings from static electricity arcing through the bearings is something that will be very low down on my worry list.

 

I tend to agree, Brendan. The wheel bearings should be relatively isolated from electrical currents, but when you think that the subframes and monocoque are all part of the ground path for nearly every electrical circuit in the vehicle, including the alternator and starter, and that tires can generate static electric charge that could build up in the wheel hub and discharge through the bearings, it's not inconceivable that a bearing could be subjected to damage from electric currents over time. Timken has obviously seen it enough to include it in its Damage Analysis manual, and Jaguar was concerned enough about the possibility to add the ground straps.

Cheers,

Don

 

Wow, that's something completely new to me ..... and interesting.

 

I would think it has to do with the ABS brake ground

 

Hi steven300,

The ABS wheel speed sensors are grounded via their own two-wire harnesses. See post #4 for the explanation of these hub ground straps.

Cheers,

Don