It is never pleasant to perceive a sound that you don’t know where it comes from. So, what if you discover a gearbox noise that continues on your smart forfour? It is most likely to be a minor issues, but before making sure of that, it is best to do a few verifications. Our staff has composed this content to help you to resolve it. First, we will see what the sources and different gearbox noises can be on smart forfour, and second, what are the solutions available to you. 
The several noises and their sources
A gearbox / your transmission is the significant part of the transmission, it is linked to the clutch that will release the engine force on the gearbox mechanisms. Finding out noises from your smart forfour’s gearbox is never a good indicator, its repair is pretty much impossible to execute due to the lack of special mecanician and its replacing necessitates a heavy expense. The advantages is that generally its life expectancy after a first noise is reasonably long, which provides you time to program the repair, but it is important to examine immediately what is your specific issues.
Your smart forfour transmission generates noise in neutral
If you encounter a gearbox noise even when you are in neutral, it shows that the gearbox’s internal mechanisms are already well worn and that you will have to swap it quickly. In fact, if you are not even with a gear on and it produces sound, the pinions must already be at the end of their life.
You hear a squeaking, a humming noise at the time of the gear shift
If you are unfortunately feeling squeaks, or humming noises when you switch the gears of your smart forfour, it is unfortunately a good bet that it is your gears that are starting to fatigued. If this sound is not limited to passing the first gear and keep going when you drive and shift other gears. This is most likely an indicator of a gearbox which is nearly good to be replace. If you have the feeling after examining that the noise comes from the clutch and not the gearbox, we suggest you to browse this content page to be able to find the origins and solutions to a clutch noise on smart forfour.
You encounter a whinning or hummin sound from the gearbox of your smart forfour
Finally, if you hear a noise almost like a humming or whinning sound on the transmssion of your smart forfour, it is very often the case that the gearbox of your smart forfour lacks oil. In fact, if it lacks oil, the elements will be exposed and grind agaisnt each other. In addition, each of its contacts will produce chips or metal dust that will mix with the oil and create even greater resistance to mechanisms that are already worn out, a snowball effect will appear if you do not almost instantly change the oil. In this situation the oil should be black and your can can smell burning. On occasion this sort of noises will be linked to a release bearing on smart forfour, don’t hesitate to look at our content page.
The solutions available if you have a gearbox noise on your smart forfour
- Verify the gearbox oil of your smart forfour via the level gauge and reflect on swapping it if the oil is black
- Use the double clutch to try to make it last till you’re able to replace the gearbox, this will limit the already advanced wear of your gearbox and limit the wear of the pinions.
- Start looking for a second-hand or new gearbox, very few professionals have the ability to change damaged parts in your own system, they will almost always offer you a standard exchange.
