http://www.trucknetuk.com/phpBB/viewtopic.php?f=2&t=20253&start=30 - about 4 posts down.
you would do better posting in one of the dedicated truck forums you would have found whilst doing your own search for a solution - you DID try searching for yourself, didn't you?
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix lorries/trucks.