I took my 2001 Defender Td5 into my local garage because of whining coming from the clutch and a clunk when changing gear. The clutch and dual-mass flywheel were found to be worn, so both were replaced along with the spigot bearing.
About a week later, as I was parking up, a loud metallic bang came from underneath the vehicle – as if the chassis had been hit with a hammer.
I went back to the garage, who said they could find no noticeable reason for the bang. They suggested it could have been the CV joint, because when the bang occurred I had the steering on full lock. It drives okay now, although there’s once again a slight clunk when changing gear.
Could the bang have come from a failure in the new DMF or clutch? Or is it likely to be an unrelated problem?
John Hampton, Somerset
There are many causes of a clunking noise, not all related to the clutch.
Your garage is right that a failed CV joint may present a clunking noise, usually when the steering is at or near full lock.
Check that your axle halfshaft driving members aren’t worn; if one or more of them has some wear, this can manifest itself through clunking, especially when drive is taken up (such as when setting off or changing gear). Even a small amount of wear in the splines can cause clunking. Are the propshaft splines and UJs in good order? Wear in one of these can cause clonking or vibration. A worn diff can also cause this noise.
Finally, check the vehicle isn’t stuck in diff lock. This would cause the diffs to wind up as you drive; in such circumstances the wind-up in the transmission will inevitably release itself every now and again – complete with a loud bang.
This workshop advice appeared in the December 2015 issue of LRO. Back issues are available to download on digital devices here.