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Matt
Matt, Engineer
Category: Car
Satisfied Customers: 20599
Experience:  Honors degree in Mechanical Engineering, worked 8 years as a Formula 1 engine engineer.
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I have a 2002 Discovery V8 auto, When idling there is a loud

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I have a 2002 Discovery V8 auto, When idling there is a loud 'clanking' noise coming from the gearbox area. It's louder when the gearbox is hot. It drives and changes gear normally. Any advice would be appreciated.
Hello

I'd take a look at the colour of the transmission oil it should be a dark red colour if its black then its needs changing together with its oil filter. Also check its level with the gearbox warm and just after you've moved the selector through all the positions leaving it for a few seconds in each one and then back to park.

You can top up the box through the dipstick tube if required and make sure you use the correct oil for your car as the fluids are not all the same. Some manufacturers recommended a change of the type of fluid - Speak to the local dealer and parts dept - they will advise you on the updated fluid to use..

also check the condition of the prop centre mount, the centre bearing is quite loosely mounted so this can be moved normally but if you can run the car in gear with the wheels off the ground and then feel the centre bearing housing for vibration if there's any then consider replacing the unit

also check for worn mountings - check the tightness of the engine and gearbox mounts and their condition - this is best done by using a jack to take the weight of the engine off the mounts and seeing if any cracks or splits open up in the rubber.Also check the tightness of the mounts bolts
Hello Les

I see that you're dissatisfied with my answer

how can I help further?
Customer: replied 3 years ago.


The Discovery Gearbox does not have a dipstick and the propshaft doesn't have a centre bearing. The clanking is metalic when the vehicle is stationary and the selector is on Park so the propshaft isn't rotating. The Engine is at idle.

Customer: replied 3 years ago.


The Discovery gearbox doesn't have a dipstick nor does the propshaft have a centre bearing. The clanking is metalic with the engine at idle and the vehicle stationary with the selector in 'Park'.

Hello Les

thanks for the extra information, in that case there should be a oil level plug on the side of the gearbox casing and the oil should just be running out with the vehicle level and the engine warm

the reason I say to check the oil level and colour is that this sounds like either a worn lay shaft gear or faulty torque convertor and both of these will discolour the oil

and a low oil level will also allow the torque convertor to move back on forth on its shaft and produce other noises inside the gearbox


so if these are both OK then check the mountings as I suggest
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