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My 2004 XKR 4.2 . has developed an annoying problem, when slowing to a stop, I can hear and feel the car changing down gear sometimes with quite a audible clunk, this problem is intermittent. Hartwells Bristol have reset the gearbox 3 times but no change. Of course when they test drive the car it behaves perfectly !! Any sugestions gratefully received.

Early versions of the 6 speed gearbox went through a period when this type of fault (occasional clunking into first gear) was not unknown. Most cars were cured by reflashing the software as presumably your dealer has been doing. However, some were not and at the time, gearboxes were replaced under warranty. I am not aware of any instances of the original symptom resulting in gearbox failure (other readers please supply information if they know otherwise) but it does spoil the normal smooth progress of an XK8. Equally, any backlash in the driveline (gearbox, UJs, diff, drive shaft splines) could give rise to clunks. In other cars, I've even come across damaged crankshaft thrust washers which have produced a similar symptom. If you've not got the facilities to check these these items, it might be better to get a second opinion from a Jaguar specialist like David Marks to aid rapid diagnosis. Mike.

hi Mike. thanks for that information as hartwells seem unsure what to do I have just sent a e.mail off to david marks i await his reply regards Mike