Gearbox / transmission noise!

[MHux1701]

Hi Folks,

I'd appreciate a little help with my '99 A140 that has developed a noise from the transmission / driveshaft area. Only just started being audible and I ain't a clue what it is!

The noise sounds like clicking at low speed which becomes faster at higher speeds.

Interestingly the noise is only audible when the car is rolling forward slowly and out of gear. Put the car in gear, or simply move the gear lever towards a gear to engage it and the noise disappears. The noise can't be heard when driving (even very slowly). Engaging or disengaging the clutch using the pedal has no effect.

Raising the car and rotating either of the front wheels produces the clicking which, using my mechanics stethoscope seems to originate where the driveshafts enter the gearbox area.

Any comments?

Martin

 

[jibcl500]

CV joints at a guess.

jib

 

[brandwooddixon]

I think that its normal behaviour for MB auto boxes.
They don't like freewheeling in neutral.

 

[Ellsy Tanners]

I second the c.v joint as jib.

 

[brandwooddixon]

Well I suppose it could be a CV joint for an A class.

I only mentioned it because both of my W210s would do this if I freewheeled with the engine running and the gearbox in nuetral.

I first discovered this when in traffic on a hill. At the time I just put the gearbox in nuetral and allowed the car to freewheel. As speed increased the clicking got more frantic until a warning message was displayed. Putting the car back in gear cleared the warning.