Towing A 453 Fortwo & Forfour

Warning

Mercedes UK state that the 453 can’t be towed more than 30 miles at 30mph. This is the same shit they’ve been spouting for 20 years.
So far I have heard of 2 people who have dragged towed an auto 453 and then discovered massive transmission oil leaks under the car resulting in the owner needing to purchase a new gearbox. They claimed that they followed the instructions perfectly (but of course that’s what they say) but considering how many of these are being towed, I’d expect to hear many more people with the same issue.

There was a suggestion that the flat towing guide released by smart is for US smarts only. It does use “authorize” instead of “authorise” so there always is that possibility but I can’t see any difference in part numbers or wiring between the US and Euro versions so I suspect it’s just a handful of people who got it wrong.

Conclusion

The fact that smart can’t even get their facts straight is a concern. So I can’t recommend flat towing a DCT 453 so if you do it, it’s up to you.

Preparing The DCT Vehicle For Towing

Contact an authorised smart center for information on recommended tow bar equipment and installing a matching on/off switch on the battery terminal. Do not flat tow the vehicle with the front axle raised. Doing so may cause serious damage to the brake system which is not covered by the smart Limited Warranty.

Failure to follow the recommendations for flat towing can cause damage to your vehicle:

Not following the battery disconnect procedure properly may result in data loss in the vehicle’s control units.

Not disconnecting the battery and leaving the key in starter switch position 1 (ignition on) may result in a flat battery and the ESP being activated during towing. Active braking action through the ESP may seriously damage the braking system which is not covered by the smart warranty.

Flat Towing 453 DCT 6-Speed Auto (Twinamic)

Before towing your smart fortwo 453 DCT, follow these simple instructions in this order.

Engage the parking brake.
Make sure the ignition is switched on.
Press the brake pedal and keep it pressed.
Move the gear selector lever down to D and then over to manual.

Move the gear selector lever back to the downshifting position and hold it for about 30 seconds.

Gearbox engages defined gears for dinghy towing.
Wait approximately 30 seconds until the 6th gear is displayed in the instrument cluster.
Release the gear selector lever and leave it in the manual shifting lane.
Release the brake pedal.
Confirm that 6th gear is still shown in the instrument cluster.

Switch off the ignition.
Wait approximately 10 seconds.
Leave the key in the ignition.
Turn the battery off using the previously installed battery switch or disconnect battery.
Release the parking brake.

Exiting Flat Tow Mode

Engage the parking brake.
Turn the battery on using the previously installed battery switch or reconnect battery.
Depress the brake pedal and keep it pressed.
Switch on the ignition.
Move the gear sector lever to park position P.
Ensure ‘P’ is shown in the instrument cluster.
Release the brake pedal.
Switch off the ignition and remove the key from the starter switch.
Lock the doors.

Leaving Dinghy Towing

Moving the gear selector lever out of manual row will abort the flat towing program.

Gearbox engages defined gears.

Flat Towing 453 5-Speed Manual

Put the car in neutral, release the handbrake and make sure the car can be rolled by pushing.

Flat Towing an Electric Drive

Turn the key to position 2 and put the car in Neutral (N). Release the handbrake and ensure that the car can be free wheeled by pushing it in each direction.

DCT Towing Issues

In 2020 I had an email from a guy saying that, after towing, there was a massive fluid leak from the gearbox area. He tried to explain where the fluid was coming from but I couldn’t really work out where he was talking about. Smart told him that a new gearbox was required as he’d not entered towing mode correctly. After that, I didn’t hear from him regarding an outcome. It was a 1 off so it went out of my head.

Then just over 2 years later I had another message from a guy with the same fault. This time the position was explained better but it confused the issue even more.

Originally I thought the gearbox fluid had leaked but now I think it could be engine oil since the area it’s leaking from isn’t where any fluid should be (the clutch area). So now there are 3 options I can think of.

1 – Tow mode wasn’t entered correctly and the gearbox was spinning at an overspeed, the fluid over heated and the gearbox input shaft seal popped because of the heat and pressure.
2 – Tow mode wasn’t entered correctly and the engine was spinning at an overspeed, the oil over heated and the engine output shaft seal popped because of the heat and pressure.
3 – The car started off in tow mode but rough road conditions managed to cause the clutch actuator to release from its locked position and engage the clutch.

Conclusion

Don’t tow the DCT 453. It’s unlikely to go wrong if you do it correctly but it can go wrong and it’ll not be a cheap fix.