metallic clunking at drive shaft

that's best how to describe it ...

at worst it is real annoying, but it only shows itself every once in a while.

I had a look today at the drive train and this is what I found:
- rear flex joint looks new and has no cracks
- ditto to front
- bearing carrier has some play, but it's not loose and looks OK
- rubber boot covering splines in tact and splines are clean and lightly greased.
- no other drive shaft sounds (i.e. humming or the like)

when banging against the front section of the drive shaft I managed to recreate the annoying sound. It sounds like there is another tube inside the drive shaft and that by banging against it (by hand) I manage to get the two to 'clunk'.

Is there two sections of pipe in the front part of the drive shaft ? What would be loose inside the shaft ?

It must be of considerable length (about the same as that of the outer shaft) and affixed by flexible means to cause the symptoms I describe.

Does this sound like any known part of the drive shaft front half ?

As I said, it's rather annoying, very intermittent and looks like it will cause the shaft to be removed to get to the bottom of this ....

Any pointers into this will be appreciated !

oh, it's a Euro 200E 4 speed manual.

TIA
L

Can anyone shed some light on the construction of the front part of the drive shaft then ?

TIA
L

[engatwork]

My first thought is, although the flex disc look good they may need to be replaced. They wear by the bolt hole being "wallowed" out and you probably can't see it unless you remove the fastening bolts.

hi, engatwork

I do not notice any radial play apart from the normal drive train play - i.e. I can not get the shaft to turn when the diff / gearbox play has been taken up. That kinda illiminates (sp?) disk wear - I'll check anyway ....

whaddaya think of the noise maide when banging against the front shaft? Really sounds like there is another pipe, of only slightly smaller dimension inside the shaft and it strikes the side of the external shaft when I smack the outer shaft ...

thanks for your reply ...

L

I've seen two cars in which the deterioration of the rubber allowed the rear end of the transmission to sag enough to produce weird noises from the misalignment of driveline parts. In the case of one '76 Volvo 245, the front u-joint was actually lightly tapping the crossmember, but in the case of a '91 BMW, the noise produced was a rumble in the center driveshaft bearing.

I would suggest that you THOROUGHLY re inspect the front flex disk. As engatwork said, the bolt holes wallow out. You have to wiggle it around a good bit when underneath to determine the condition of the flex disk. Mine ALMOST went undetected when I was looking for my problem. I had to shake around a good bit to find it.

The front disk will go long before the rear because it is exposed to the engine and catalytic converter heat.

Good luck,

[JDUB]

Check to see if the centering sleeve in the front of the driveshaft is ok. Some mechanics say they have never seen on go bad, but I have, mine somehow got damaged and it looked like someone hammered on it.

Hi, All

thanks for replying, JDUB, LarryBible, Fimum Fit & engatwork.

I'll dismantle the front of the shaft at the flex disk (after marking everything properly) to inspect the shaft and the flex disk whilst standing up

I will not be able to do this anytime soon, but seeing that neither of you did raise any serious warnings, and becasue I do not have this noise all the time, I wait for a more milder highveld winters day ...

thanks again !

L