Backlash when letting clutch out

[Z2TT]

Hi.

I got a E30 325i and I hear a clunk-clunk-clunk noise when I let out the clutch mainly at slow speeds going out of reverse and 1st gear.

Also while driving, if on a certain gear, mainly 4th I let off the gas quickly I would hear and feel a clunking/shaking in the drivetrain.

The guibo is good, the clutch doesn't appear to slip. I assume the centre bearing is good as the driveshaft doesn't have too much up/down movement.

Could it be loose gearing in the diff, or clutch/flexplate issue?

Cheers.

[Z2TT]

Any ideas guys?

I have been told my rear half shafts have freeplay, could this be a cause?

Seems to be getting worser even has a clunk when letting on/off the throttle when driving in gear.

[jlevie]

This could be worn half shafts, worn drive shaft, or a worn differential. With the car on a lift further diagnosis is possible.

[Z2TT]

Half shafts have been changed with good ones just today.

The driveshaft does have play, you hear a clunk if you move it.

I am wondering is it the Uni's that normally let go in these shafts, or is it the centre spline joint?

I'd like to have the parts on hand because I have been told you cant inspect all the Uni's as one of them is above a heat shield

From what I understand there is a bush that goes on the slip joint that I have been told wears, does replacing this normally fix everything or can the metal on the splines wear itself?

[jlevie]

If you hear free play when rotating the drive shaft back and forth, the u-joints are worn. The fix is to replace the drive shaft (and center bearing) with good used parts, or a reman assembly (I like those from Drive Line Services). Personally, I'd only go for a reman unit.

[Z2TT]

Hi

Just head the heatshields off today to access the driveshaft. U-Joints do not have play in them, hardly any. The Centre Support bearing is good and not much up/down movement.

The centre slip spline joint does have a small amount of play.

I have been told it may be engine related, e.g stalling when giving it small amount of throttle.

At times when driving there will be a clunk clunk clunk from the driveline when I give it a small bit of gas, or when letting the clutch out and putting it in when at speed.

I had suspected the drive shaft to be extremely worn but it wasn't it's in good condition.

[jlevie]

There should be no play at all in the u-joints and they should be silky smooth. You really have to have the drive shaft out of the car to assess it's condition. Also check the differential mounting bolts and the differential bushing.