Autobox clonk

Transmissions, Transfer Boxes, Axles, Drive Shafts
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Clem
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Autobox clonk

Post by Clem » 30 Sep 2013 06:09

Guys, when I've been driving at speed and coast to a stop at an open road intersection, just before I come to a dead stop, there is a single clonk as the box shifts down; ie a slightly harsh downshift. Is that normal? A new 4.8 GRX.

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David
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Re: Autobox clonk

Post by David » 30 Sep 2013 07:20

Hi Clem.

Mine also did it from day one. I think it is related to the idling speed and it's behavior changes with your driving style.
Try coasting in slowly before you come to a stop.

Check out this link: Thud

You can also try resetting the TCU by unplugging it over-night and by adjusting your timing to 10 degrees advance as yours are more than likely still a factory stock 5 degrees.

Must say it is quite an unrefined clunk :surprised:

Let us know if that helps :thumbup:
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Clem
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Re: Autobox clonk

Post by Clem » 30 Sep 2013 08:07

David wrote:Hi Clem.

Mine also did it from day one. I think it is related to the idling speed and it's behavior changes with your driving style.
Try coasting in slowly before you come to a stop.

Check out this link: Thud

You can also try resetting the TCU by unplugging it over-night and by adjusting your timing to 10 degrees advance as yours are more than likely still a factory stock 5 degrees.

Must say it is quite an unrefined clunk :surprised:

Let us know if that helps :thumbup:
Many thanks for the input David. I'm not sure about the aircon thing - will monitor but I think in my case I did not have it on, but I could be mistaken. The TCU is the transmission control unit? Maybe I can just disconnect the man in batty overnight instead? 5 degrees advance on the engine timing? If that's all it has I probably really should get it changed - obviously set to cope with really low grade fuel (?).

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David
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Re: Autobox clonk

Post by David » 30 Sep 2013 10:46

You can do so but it is actually very easy to disconnect the TCU.

Stick your head under the dash drivers side. It is mounted below the radio. It has a lever that flips open and then the connections can be removed. :thumbup:

If you disconnect the battery your radio will ask for a code and you will have to reset all the stations :doh:

David
2006 Patrol 4.8 GRX Tiptronic Y61/GU(4)
ARB Bullbar, TJM 2" Suspension, Snorkel, 285/70/17 BFG KO2's, 40L Engel, Nuvi 1410, TPMS, SatNav

Stop Rhino Poaching Supporter!

Clem
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Re: Autobox clonk

Post by Clem » 30 Sep 2013 12:58

Thank you David.

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