How to repair and overhaul defective gearbox

Especially with older years of construction, the question arises in the face of expensive repairs: “Is it still worth it for my car?” And if not, where can I get an affordable vehicle quickly?
Although garages offer new gearboxes from the original manufacturer, replacement gearboxes are usually cheaper. If the market value of a car at the time of the gearbox damage is below a certain amount, the repair effort is no longer worthwhile. The sum of wages and procurement of materials quickly exceeds the value of the car. Here it means looking for a hobbyist who buys the car and looking for a technically perfect used car yourself. This does not apply to car owners who know how to help themselves or who know someone who can carry out such repairs professionally as a courtesy.

Causes of defective gears

There are several reasons for broken car transmissions – human or technical in nature, or sometimes a combination of both. Securing the car standing on a slope with reverse gear is quite normal. However, to decouple the vehicle that has started and is already rolling and to let the gear “come” while moving forward is a very safe method of ruining a transmission through human error. A blatant example, but unfortunately in this way and in a similar form is often the reason for the expensive workshop bill that follows. Of course, the car industry and its suppliers are not perfect either; material defects and production breakdowns are therefore also among the causes of gear damage. Incorrect oil levels can also be the cause of later expensive and often even avoidable repair bills. A heat overload and a number of other reasons can also severely damage the gearbox or individual parts – up to a total failure, where only a replacement can help.

Early detection avoids greater damage

Transmission damage can lead the driver into extremely dangerous situations – just think of the awkward situation of being stranded in the middle of a motorway construction site, narrow and already full of dangers, due to a defective transmission. That’s why it’s important to know your vehicle well and to take every change when shifting and clutching seriously. It could be that the attention to detail makes the repair cheaper in the end, since not the entire transmission but only one component has to be replaced. Drivers often only experience failures because of a fault in the transmission control unit – that does not mean that the entire transmission is defective. A company that can eliminate such errors is, for example, EPS Elektronik GmbH & Co. KG.

Compare prices between original part and replacement parts

The extent to which the price gap can widen between an original part and the appropriate replacement part quickly becomes clear from a few examples: For a Mazda 6, a customer received an offer for the diesel pump that needed to be replaced (after filling up with contaminated fuel from a petrol station in Germany!) – she should cost over 2000 euros. In addition, the removal of the broken pump, the installation, and the cleaning of the tank and diesel line – the total calculation in the cost estimate was very close to the 3000 euro mark. Only when the customer asked, did the contract mechanic look for a replacement pump, which was significantly cheaper at less than 1000 euros. This was ultimately installed, which saved the car owner more than 1000 euros in repair costs.

Transmission repair costs

The situation is similar for a gearbox. Depending on whether it is an automatic or manual transmission, the price can differ by as much as 50 percent. Of course, there are always arguments in favor of an original spare part. However, a 100% suitable replacement transmission, which also comes with a guarantee, can definitely be the more attractive choice in view of the factor of the current value of the vehicle and the associated profitability of such a repair. It is important that you know for sure that the gearbox – and not just individual components – is really defective.

The car should be taken to the nearest workshop to be checked if

• sporadic or constant noises (a kind of rustling or rattling) can be heard when shifting gears.
• the aisle jumps out on its own.
• the gear lever can no longer be moved into neutral without problems. Shifting problems from one gear to the other also occur if the transmission has a defect.
• the correct gear has actually been engaged, but the engine still remains idling.
• the vehicle falters when driving and no longer runs smoothly.
• Gear oil leaks out.

Mileage, load and age of the vehicle are not always responsible for gearbox damage. As already mentioned, a material or production defect can also be the reason for a very early damage. If the above problems occur individually or in combination during the first few months or after a few kilometers after buying a new car, you should contact the car salesman. In this case, it is essential to make use of the warranty or (after a longer term) to at least insist on a goodwill repair. Rivets are installed inside the gearbox. If these come loose for whatever reason, they shoot through the gears like small projectiles and cause irreparable damage. In this case, you must contact the manufacturer or its authorized dealer from whom the vehicle was purchased in order to assert your claims. Nonetheless, having to bring the vehicle in for this costly repair is annoying, time-consuming and inconvenient.

Replacement gearbox or original replacement?

As described above, the authorized dealer will first suggest the original transmission to the car owner for replacement if it determines that the entire transmission complex needs to be replaced and not just a single component. This is significantly more expensive than a replacement gearbox. A replacement gearbox is a used system. If it comes from a reputable source and not from some junkyard or dubious auction offer, it has been completely overhauled and is therefore fully functional again. This means that a car owner can save several hundred euros compared to branded gearboxes that come brand new from the manufacturer.

The replacement gearbox is particularly recommended for older people on four wheels or car owners with a tight budget. However, it must also be said that as a layman you only save on spare parts, but not on the wages for converting the transmission and other preliminary work.

If you don’t have a competent mechanic on hand (or aren’t one yourself), you have to pay full price here. You can see how the gearbox actually works in this short video.

Car hobbyists with extended basic knowledge are more likely to manage the gearbox repair in a rental workshop where – if problems arise – a master mechanic offers his help (for a fee). Of course, the decision as to whether a new transmission from the manufacturer or a replacement transmission should be installed is up to each car owner. It is important that non-professionals do not try to change the transmission themselves in a fit of saving rage. The risk of putting yourself and others in extremely dangerous situations on the road and even causing an accident is very high. In addition, the (financial emergency) situation can definitely be aggravated by false ambition: If the replacement gearbox is damaged due to mistakes made during installation, the damage is twice as great and the problem that you cannot use a vehicle for commuting and the like, given even longer. Even if it is hard; the wages for the mechanics have to be paid, unless it is a guarantee or goodwill case.