Magnet on the gearbox - myth or not?
Discussion
I'm in Calais, waiting for a ferry. The guy 2 lanes over from me got out of his cab, reached between the chassis rails at the back of the cab, and retrieved a small object - I couldn't see what it was. He then put it in the door pocket, and walked away.
Could it have been a magnet, or is there a simple, less dramatic explanation?
Could it have been a magnet, or is there a simple, less dramatic explanation?
That's it. It's a Hall Effect sensor, like most current speedo drives. I'd heard stories of drivers placing magnets near the speedo drive to disrupt the signal to the tachograph head.
It means (as long as you're not caught) that you can go faster than you should, or not be subject to drivers hours regulations. Thus, you could drive for far more hours in a day than you're supposed to, and gain a competitive advantage.
It means (as long as you're not caught) that you can go faster than you should, or not be subject to drivers hours regulations. Thus, you could drive for far more hours in a day than you're supposed to, and gain a competitive advantage.
Works exactly as other posters have said by interrupting the magnetic field of the sensor.
The new Tachograph standard to be fitted to all new trucks first registered from October 2012 will (should) eliminate this as they require two speed signals e.g. gearbox speed sensor and ABS. The Tachograph will compare the two signals and make sure they are within a tolerance. If not, it will flag a fault code.
For M1N1 vehicles like pickups where we already use the ABS signal as the main speed input, we will be fitting GPS secondary speed pick-ups.
The new Tachograph standard to be fitted to all new trucks first registered from October 2012 will (should) eliminate this as they require two speed signals e.g. gearbox speed sensor and ABS. The Tachograph will compare the two signals and make sure they are within a tolerance. If not, it will flag a fault code.
For M1N1 vehicles like pickups where we already use the ABS signal as the main speed input, we will be fitting GPS secondary speed pick-ups.
Cyberprog said:
The sensor on the gearbox detects the change in the magnetic field as part of the gear mechanism passes by it. Putting a magnet near it can over-ride this, so it thinks you're stationary, or similar, and therefore the tacho/limiter doesn't operate.
Yes ......But if you get caught they (VOSA/ police ) will reem a part of your lower region 
http://www.commercialmotor.com/latest-news/vosa-ta...
http://www.truckuk.net/news-item/?news=VOSA%20are%...
Up to a £5000 fine and two years in prison.
http://www.truckuk.net/news-item/?news=VOSA%20are%...
Up to a £5000 fine and two years in prison.
Falsifying drivers records has been going on since they were introduced, in fact falsifying logbooks and tachographs were all part of the norm when I worked in the industry and if you weren't prepared to do a bit of hooliting and run bent you were out of a job...
I remember hearing stories of how a certain Carlisle company who shall remain nameless boasted his drivers were all legal and never fiddled tachos, until one was stopped for a spot check and when they went back to the operators offices multiple discrepancies were found on over half the drivers tachos.
I remember hearing stories of how a certain Carlisle company who shall remain nameless boasted his drivers were all legal and never fiddled tachos, until one was stopped for a spot check and when they went back to the operators offices multiple discrepancies were found on over half the drivers tachos.
Every transport company is at it one way or another, I refuse to believe that there is a transport company that run 100% legally with regards to tachographs
Whether its tipping off cards, pulling them early or magnets, they all do something outside the law, and those that claim they don't are liars
Whether its tipping off cards, pulling them early or magnets, they all do something outside the law, and those that claim they don't are liars
Talking of which and seeing that quite a few people have posted on this one, i was just passed at maidstone services on the m20 by an old shape silver actros 4 wheeler. The copper sitting in the passenger seat with a camera looked rather dissapointed that i was just picking my nose and not on the phone 
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