W124 gearbox 'clonking' noise...your advice

[IMD]

Hi all,

My W124 e220 gearbox has started to make a bit of a clunking noise.

This happened today when I moved from P to D when stationary. When drive is taken, it makes a clunk noise and also when putting the box into Reverse. It drives smoothly and changes well, but this noise also happens if I change from D to 3 or 2 whilst on the move.

Any suggestions?

Ian

 

[WLeg]

Change the ATF !

 

[IMD]

ATF? Auto Tranmssion Filter??

 

[IMD]

But its sounds mecahnical..like something is loose?

 

[Big_Jon]

Definately suggest a change of fluid, it will sound mechanical when low on fluid, I discovered this on my SEL500, to the untrained eye the box was knackered but to me, a simple o&f change and back to silky smooth operation.

 

[IMD]

Is there a filter to change as well and is this as easy job as an engine oil change?

 

[grober]

Yes there is an internal filter to be changed which means taking off the gearbox oilpan (new gasket essential ). I would not recommend doing this unless you have good access under the car over a pit or up on a ramp. Everything must be kept scrupulously clean also. Great care must be taken to put in exactly the correct amount of fluid since overfilling can be as bad as not putting in enough. If you have the 4 speed hydraulic box I would recommend FUCHS TITAN 4000 DEXRON 3 You can get this from Opie Oils http://www.opieoils.co.uk/
I recently learned that UNIPART branded oils are made by Fuchs so perhaps thats a local alternative?

 

[Frank O' Phile]

If you can do an engine oil n filter change then you can do gearbox too. Filter sits inside the sump. Get oil, filter, sump gasket, and use a torque wrench to tighten. It's all covered here before, a quick search will reveal all.

 

[GazCaff]

I wonder if its backlash in the propshaft couplings or the diff, rather than the gearbox itself?

 

[Smiley]

I wonder if its backlash in the propshaft couplings or the diff, rather than the gearbox itself?

Thats my bet too - it is one of the joints or the centre bearing on the propshaft.
Still worth changing the ATF though if it has not been done recently. If not sure and you do not want to spend money unneccessarily (who does?) then take the dip stick out and look at the colour of the fluid - if it is a nice clear light red colour and no other problems then leave it for a while. If it looks brown or black then get it and the filter changed soon.

 

[kth286]

Are the actual gear changes on the move OK?

If they are also getting jerky perhaps you have a bad vacuum somewhere, pipe splitting or similar.

Good vacuum is important component for good auto gearbox operation.

 

[redw124]

clonking

most common are the rear subframe mountings being worn.
if it sounds like something hitting against the boot floor, this is where to look! i too own a 124 e220 and have same problem.

kev

 

[janner]

I wonder if its backlash in the propshaft couplings or the diff, rather than the gearbox itself?

^^^ What he said ^^^
Get underneath and have a look at the propshaft coupling (usually the front one) and the diff mounts.