Knocking at rear

[Rincewind]

The van has a knock at the rear which only occurs when the accelerator is pressed (81 CU Aircooled 4speed)

can't hear it at low speed or when revving stood still but quite noticable at 45-50mph on the road.

bizarrely stops as the steering wheel is turned left.


Any ideas?

I been having a read, could it be the gearbox mount?

Cheers

[Gadders]

Loose wheel nut ? Can cause knocking sound if only one is slightly loose

[HarryMann]

You will have to get down and get a bit dirty to find it..

Start with getting rear wheels off the ground and checking for rock or looseness in both planes (asap safety)
Check rotational play isn't excessive (gbox)

Up on stands or over pit and check all the engine and box mount (big lever and sharp eyes)
Exhaust fixings
Rattle the driveshafts up down/side to side both sides both inner & outer (check while at it) joint boots and gbox output (flange) seals (drips)
Check gear linkage shafts and bushes (rattle around)

[cozmik]

Does it sound like a giant chicken clucking?

Then it's the CV joint.

Grip it firmly, give it a bit of a w*nk for 2 minutes to redistribute the grease inside.

Ta Da!

Sorry for graphic description, but basically that's the required motion, one we're all familiar with..!

OK some more than others

[HarryMann]

Or squeeze the boot to force the grease into the joint or even pop it right off and pack some more in... MS02

[toomanytoys]

I'd be checking wheel nuts first.. then see if any CV joint bolts are loose.
Also might be worth checking the rear hub nuts are tight too..

[HarryMann]

I'd be checking wheel nuts first.. then see if any CV joint bolts are loose.

He's right you know!