Checking Gearbox Oil

[Neil1971]

How do i check the gearbox oil on a W140 S Class 420?

 

[television]

You either need to buy a dip stick from MB at £35 or you can use a length of curtain wire, where when it touches the bottom it should read about 5.6 cm up the wire with the car hot after a drive you will need to get a new locking tab for the cap

 

[mikestrivens]

Mine has the atf dip stick insitu, and is very easy to check, just like the engine.

 

[television]

Mine has the atf dip stick insitu, and is very easy to check, just like the engine.

Mid 1996 they went over to the 722.6 box and these did not come with dip sticks

 

[Neil1971]

Thanks Guys. I will sort out a dipstick and a cap and check it. Had a real funny problem with the gearbox. Tried to put it in drive and nothing happened but just revved up. Turned the engine off and started again and it went in. Then driving home it was stuck in 3rd gear think it was in limp mode. I had the oil changed in box about 6 months ago and had a new filter and seals put in. Any idea how much oil is supposed to go in the box?

 

[Miffy]

around seven and half litres I think for a full change, but dip the box and check its between 54mm and 65mm and you can at least rule out the atf volume

 

[mikestrivens]

My Indie told me of a car that had been serviced by kwikfit. They had sucked the oil from the atf tube and then put 7 litres of atf fluid into the engine. Both engine and gearbox were destroyed.

 

[mr_w140]

You either need to buy a dip stick from MB at £35 or you can use a length of curtain wire, where when it touches the bottom it should read about 5.6 cm up the wire with the car hot after a drive you will need to get a new locking tab for the cap

Hello Malcolm,

I hope that you are keeping well!

My old w140 S320 LWB P reg - 1996 model had been parked for some time and I noticed that oil had been leaking. I took it for a drive and it was very sluggish. I checked the gearbox (following your guidelines using a curtain wire) and I was surprised to see the level on the wire was upto 1cm only!

I noticed that the handbrake pedal is also very hard to depress when activating the handbrake, could this be anyway linked to the very low gearbox oil level as well?

I haven't checked or topped up gearbox oil before because I was told it is a specialist MB job but is it just a case of finding the right oil and putting it through the filler loop?

Thank you for your advise.

Sami