Manual Transmission Oil: Does it matter or not?


Changing the oil in the manual transmission? Is that necessary? Some time ago gears used to be considered eternal, but now you often hear about the damage caused by driving with old oil.

Even if the manufacturer does not recommend changing the oil, sometimes it is advisable to change the oil in the gearbox.
transmission can mean problems!

Why be smarter than the manufacturer? If the manufacturer writes that the oil in the gearbox does not have to be changed, is it worth exaggerating? Definitely yes, and for several reasons. Most importantly, fresh oil can prevent major breakdowns.

Fresh oil lubricates the bearings better

This will certainly be confirmed by the users Toyota Corolle, in which the manufacturer did not prescribe gear oil change. However, to avoid the need to replace the bearings (mainly fifth gear) after about 150 thousand. km, oil needs to be replaced even every 60.000 km on! The driver will love it too Opel Astra X and Zafira B, in which the famous (unfortunately, not durable) M32 gearbox works - oil change is one of the few activities we can do to protect ourselves from problems, and there are many of them: worn bearings, cracked housing, broken teeth.

Remember that the manufacturer, when it says "for the whole life of the car", does not mean 20 years and 500 thousand. km, already half this time and distance. During operation (or elapsed time), the oil loses its properties - in addition to lubrication (you also need the right viscosity), it must also be cooled, protected from corrosion, etc. Although it has better working conditions than engine oil (lower temperatures, no exhaust fumes), it is also old! The last argument for replacement may be the low price.


The right gearbox oil selection is the basis of a good deal

We hope we have convinced you of the need to change the oil. Can you do it yourself? In most cases, yes, but a mechanic can wait for a few pitfalls, causing problems even for professionals.

The first thing is to prepare the right oil. While poor viscosity choices can illuminate, for example, winter problems or improper lubrication during the summer, applying another API (American Oil Institute) than necessary can lead to the destruction of portable parts after several thousand miles! Theoretically, the higher the class (GL-3, 4, 5 or even 6), the better the preparation for harsh conditions (GL-5 has twice as many anti-wear additives as GL-4), however, the use of GL-5 oil in improper gearboxes can destroy, on
example, non-ferrous metal synchronous!

Some manufacturers do not specify the parameters of the oil, they only give their standard. Oil producers are ready for that - they are developing products that meet these requirements. Some companies, such as Honda or (Lada Samara), recommend a gear oil viscosity… 10W-40 (especially for gearboxes or engines!). If the transmission is lubricated together with a differential that has, for example, limited friction, then it may require the LS additive (limited slip). We will not give specific brands of recommended oils, but sometimes it is worth browsing professional websites and getting feedback from forums focused on a given model, because it may turn out that in certain cases some oils will work better than others.

Oil cannot always be easily changed

The oil is being bought, it's time to replace it. If everything goes smoothly, it will take a few minutes. The box should be heated to the right temperature (only a few kilometers).

Each gearbox manufacturer has its own system design. The gearbox usually has two screw plugs - the one located just below half of the gearbox was used for topping up and filling. It was enough to turn away and see if there was oil under the finger. When adding oil, it is necessary to wait for the oil to appear in the hole. There was an oil drain plug at the lowest possible point of the gearbox housing.

We always start by unscrewing the… plug! If there is a problem with this (with the corresponding key, location…) the operation can be postponed. If you drain the oil earlier - the car will be disabled.

NOTE: Do not unscrew the transmission if you are not sure of its intended use!

It is sometimes easy to find an oil filler plug, for example, a vehicle speed sensor, a reverse travel sensor or a vent, fitted to the housing.

Often you cannot rely on the topping because the amount of oil you supply
the manufacturer searches for, for example, 1 cm below the hole (or topping oil from the top
laptop). Therefore, it is necessary to pour a precisely measured quantity of oil, without suggesting its level.

There are cars (e.g. Ford's) in which there is no drain plug. Sometimes it may also turn out that the right flap needs to be unscrewed, e.g. differential or underbody cover (Daewoo Lanos). The oil can be changed by suction or, for example, when replacing the clutch (when it is necessary to remove the transmission and rotate so that the oil leaks, eg near the shaft). Depending on the transmission and model, there may be other surprises waiting: for example, Opel suggests replacing the transmission plug, sometimes it is necessary to use a gasket or additional elements (eg clips to be destroyed, disassemble battery, cover, etc.). .
Although changing the oil in an engine or automatic drive is more important than with a manual transmission, this should definitely not be neglected!

Transmission Oil Change

Manufacturers often provide information on gearbox oil change intervals. It can be 30.000 km as well as 200.000 km on. If you do not have the right information, you can assume that the oil will last until the end of the transmission. However, it is worth paying attention to the often overlooked reservations about using a car in difficult conditions. It has been shown that, for example, in the city or while trailers are being towed, theoretically essential oil should be replaced with new oil. Even if the manufacturer assumes that the oil does not need to be replaced, we think it is worth it. At what frequency? Depends on car brand, transmission model, etc. If there are no additional indications (e.g. the tendency of the box to carry bearings), it is worth doing every 80-100 thousand. km or every 8-10 years.

Drain plugs sometimes have magnets on which sawdust accumulates. You should watch them - it gives an overview of the state of transmission. Plugs can have seals (eg copper washers) or it is recommended to use a sealant (not very sticky). Pour fresh oil - in this case you need to measure it carefully, but it can be pulled into the chest by gravity from the tank, a syringe is not needed.

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