Autobox oil change

I recently bought a 1998 Mercedes-benz 230 CLK with 171,141 miles and lots of service history. I have just done an oil and filter change, and I would like to change the autobox fluid, but there is no dipstick to check the level. I have been told that the autobox has to go to a Mercedes dealer for computer diagnostics to check the level. I have also been told that Mercedes sell a special tool for £50 to check the level. It’s all a bit mad – why didn’t they just fit a dipstick?

John Wright For reasons unknown, Mercedes stopped supplying a gearbox dipstick quite a few years ago. Later models no longer have a dipstick

for the engine oil either. Mercedes would probably tell you that it’s one of the ways to keep the weight down, but I suspect that it’s just one way to push owners into their workshops for servicing and repairs.

In fact, the automatic gearbox oil can be dipped in the conventional way, but does require you to buy a dipstick. Sealey makes a tool for checking the oil level (part number VS1200TD) – this costs around £20, making it far cheaper than buying the official Mercedes version. However, before you can remove the cap that covers the top of the gearbox dipstick tube, it is necessary to extract the small red plastic retaining pin.

When changing the auto gearbox oil, I recommend dropping the gearbox sump and replacing the strainer/ filter. Although the oil capacity of your gearbox should be 6.2 litres, some of this is retained in the torque converter, so it is unlikely you will be able to drain it all. Once the gearbox has been topped up, check the oil level with the engine running after the gear selector has been run through the gear selections and placed back in the ‘Park’ position.