small 'pop' upon applying drive

Hi guys,

I have a strange noise which seems to have appeared recently in my 2008 110 Puma (travelled approx 63,000miles)... upon applying drive (releasing the clutch) where the vehicle begins to move, I hear a small 'pop' noise coming from the drivetrain somewhere. Mostly I hear it when reversing out of my drive... straight and slightly uphill. But it can also happen forwards start in 1st, turning or straight... It also happens say when I am changing down to 2nd to corner slowly. Only happens under slow rpm and I think it only really happens once or twice on a drive.

I have never heard this type of noise before, but could it be something that is slipping slightly under load and ok when rolling? The rear diff did have a leak in it when I bought it, that was fixed by LR in London prior to delivery... maybe a lack of oil for a while in there?... or something to do with the clutch assembly maybe?

Anyway... I am at a loss and wanted some advice incase it is a sign of something needing replacing or imminent failure

Thanks in advance!

Decided to call into my local LR service centre and have a Defender 'expert' drive the car. He heard the pop noise but could not diagnose. Checked the drive shaft which was solid, and then suggested lack of grease in the swivel joints... I then went home, lifted and checked both swivel joints which had plenty of grease in them.

Could it then be something with the clutch drive shaft? Any ideas would be good as it seems to be getting more frequent during a drive (or I am just tuned for it more)... thanks heaps!

There's sometimes a noise caused by slack in the drivetrain. Even on fairly new machines the propshafts can be rotated by hand, often about an eighth or a even a quarter of a turn. A tiny bit of movement with each set of gears or splines can add up to quite a lot over the entire transmission. Obviously, you want the universal joints on the propshafts to be nice and tight, and as soon as you can feel any slack in them it is time for replacement. But many of the other transmission components have a little wear and it is not a problem. Most people experience this as a clunk rather than a pop though. So maybe there's something else in your case. But a lot depends on what's resonating, your soundproofing or padding (if any) and the way your ears work. One person's pop may be another's clunk.

In my case the biggest improvement in this kind of noise on lifting the clutch was achieved by replacing the drive flanges on the rear hubs. That quietened it down considerably.