How to treat the
lifespan of a gearbox depends on how it has been used during its life. It’s a simple
as that. If the box get’s noisy, or goes kaput, 9/10 it’s your fault only
or/and the car’s user before you, in the case if it is a used car.
buying a used car and you stumble upon a car with a sloppy stick, noisy changes
and whining driving, simply don’t buy that one. If the gearbox has been treated
that bad, how are the rest of its mechanics been used and how well have they
been maintained, if maintained at all.
when the car is out of it’s warranty-period, people seem to “forget” the maintenance
because it’s too expensive.
following points under consideration and the lifespan of your gearbox will be
significantly extended. Starting with the worst:
change oil regularly.
Though practically no manufacturer advises an oil change
for their gearboxes at all, they simply state its oil is holds for a lifetime. Why
this is I have no clue, because there’s always synchromesh wear -where the
debris eats in the gasket seals-, water can come in through its ventilation on the
top, and there’s always the leakage along the drive axles seals and between
gearbox half shells.
Leakage is the biggest gearbox killer; since there are only
a few litres in there and a leakage of a few drops a day over several years is
enough to loose too much oil from the ‘box to still function properly. But
before it is empty the fifth gear’s needle bearings will give the ghost because
of lack of lubrication, due to the fact the fifth is positioned ‘outside’ the
actual gearbox. It gets just enough lubrication when the oil is on level, but
only gets oil by chance if the level is only a bit -say half a litre- under it.
Long lefthanders don’t do any good either, in that case. Hot, thin oil on long
drives neither. And if there’s water in the oil it will become *very* thin,
since it will start to foam in that case!
So, check the level -or have it checked- at every engine
oil change. Don’t listen to the ‘sealed for life’ guarantees from the
professionals or people who think they know.
It’s as simple as undo the level plug and eventual fill up
until it refluxes. Leave it running out until it stops dripping and put the
plug back with a new seal ring.
Otherwise you are ‘carrying water to the sea’. Go cheap on the ring and it is
better not to check at all, because the plug will start to leak as a fishnet!
A gearbox oil change (which normally costs max €100/$160 if
done at the dealer) should be done every 60-100,000 km. Keep at least to the
advised grade stated in the manual, but a known brand full-synthetic is better.
Stick to the normal ones, not the friction reducing crap. Same story for add-ons:
don’t: the PTFE used in for example Slick50 causes the metal debris to continuously
float around in the oil instead of it getting caught by the magnet fitted in
every gearbox (sometimes on the end of the drain plug, sometimes in the box
itself). Plus a worn box cannot be fixed by add-ons. It simply needs an
avoid jerky power changes, such as clutch-drop launches and full throttle
accelerations followed by sudden idle (full deceleration) repeatedly.
Though for some it’s incomprehensible that a gearbox can’t
handle this abuse (“a WRC car can do that too” failing to understand it has a
straight-cut purpose-build ‘box that, even though it’s supposed to be
bullet-proof, lives for two rounds only), so they claim that “my ‘box is crap”
after they themselves totally wore out each and every single mechanical part in
Hopefully you can now make your own opinion next time you
hear a story like that.
fast gear shifts, especially in combination with short-shifts.
Largely like the above, since a road ‘box is not a
straight-cut dog ‘box, it’s made for comfort and actually has something called
synchromesh rings to make the gearshifts smoothly and noise-free (ever hear a
dog ‘box engage 1st gear?). The best way to shift gears is to “slowly”
pull it out of gear and hold it against the next gear until the gearbox’
synchromesh has done its work and the lever almost gets “sucked” into gear.
A good gearbox manages this in half a second, so it’s not
going cause you to miss your dinner.
shifting diagonally when making a
change from (for example)
3rd to 2nd. Use a square movement following the H-shape
as pointed out on the lever. Mechanically this is how it’s supposed to be done
and if not, the levers and the internal shifter-forks and its shifter-rail will
wear unnecessarily. Over time
this will show as a sloppy, gutless lever and when it becomes excessive it will be impossible to shift into reverse and/or 5th.
put your hand on the shifter when you’re not changing gears. Basically for the
same as above. Unnecessary wear on the mechanics and especially the gear used
as the armrest gear, which is normally the fifth.
under the chapter "bad habits"; don't rest your foot on the clutch
pedal either. This will keep the clutch’ thrust bearing unnecessarily engaged
over long periods and it simply cannot cope with that. It's a bit of a
waste to have a big operation like removing the gearbox from the car, just to
renew the clutch bearing.
but not least; do treat the clutch with respect. Fully depress the clutch pedal
with each and every shift. As with gearboxes, there is a significant difference
between race and road clutches. The first is made for (again) comfort, so even
your granddad can drive you car and for mechanical preservation. A road clutch
plate is made with a centre part (attached to the gearbox) and the outer part
with the friction material (connected -when the clutch is engaged- to the
flywheel of the engine and the two are separated by springs fitted in a radial
fashion around the clutch’ centre. These springs help
to isolate the transmission from the shock of the clutch engaging. All the
forces go through these springs. The more you “launch”, the more you abuse the
springs (apart from nearly every other single mechanical part of the drivetrain).
There are also waved sheet-springs between the front and backside of the
clutch’ outer plates, under the friction material. These are fitted to
progressively engage the clutch, just help you not to stall the engine. A race
clutch is one pieced, purely made to get the torque from A to B, no build-in
comfort at all. That’s one reason why it’s much easier to stall an engine when
trying to drive off, if the engine’s fitted with a race clutch. Long story
short; if you don’t have one fitted, don’t treat the standard clutch like a
race clutch and stop imitating what you see on TV.