Driving to Not Break Parts
[ January 20th, 2009 ] By: Mark Ozimek Posted in » Tips and Tricks
I came across some intruiging information earlier on the Nissan GT-R. While this may be old news to some of you, the gist of it is that Nissan is not honoring the warranty if the transmission fails after doing launches with the VDC off, and launch control on.
The GT-R has an interesting transmission, a computer controlled dual clutch sequential. So this means that Nissan has intentionally included a feature in their car that would void the warranty when used for anything other than getting the car unstuck from mud or snow. While this can be interpreted in a lot of different ways, it brings up an interesting, although blindingly obvious point to me.
Cars break.
The real question then is why do they break? For the average person, it’s likely due to improper maintainance, or simply normal wear and tear that takes out a component that may or may not be critical to the operation of the vehicle.
However, for people like Charles and I, and most likely you as well, we drive our cars hard. We expect the engineers who designed it to allow the car to be driven at full power and aggressively by including headroom in the strength and durability of critical components. But of course, even with that, there are things that you do that wear down parts, and will eventually break them.
Luckily, things are designed so that cheaper parts that are easy to replace take the brunt of the damage, protecting the more expensive components.
Aggressive turning will wear down suspension bushings, and tires a bunch. Hard shifting is hard on the clutch and engine mounts. Rough roads are also tough on the suspension bushings, and the dampers, and sometimes rattles the interior apart.
However, it’s not too hard to exceed the limits of some of these safety components and break something more important. For example, launching the car by dumping the clutch with the engine at a high rpm is very hard on the transmission, driveshafts, differentials, axles, and related bushings. It’s not uncommon for someone to break a differential gear or axle spindle when doing hard launches like so.
Something else transmission related that is hard to avoid is synchro wear. Synchros allow you to change between gears easily, and without rev-matching. In most modern manual gearboxes, the gears are always meshed together, but spin freely on a shaft. The gear is selected by engaging a ring, which then prevents the gear from rotating, and transfers the torque into the shaft. When engaging this ring, it needs to be spinning close to the same speed as the gear, or else there will be an awesome grinding noise and you won’t be able to select the gear. It is the synchro’s job to make sure everything is spinning at the right speed. However, the synchros wear out with use. Each gear shift puts a little more wear and heat into it. If you’re using the synchros a lot to make shifts that involve large RPM changes, they overheat and warp, creating a spot that rubs more than the rest, getting hotter and wearing faster, etc. So when downshifting, try to double-clutch whenever possible to reduce wear on those synchros! I know that was an awkward and cumbersome explaination, so I’m sorry, I’ll make a dedicated transmission post someday to explain it in more detail. However, we have made a video a while back on how to double-clutch if you’re not familiar with it:
In addition to that, there are plenty of other things. Keep the interior and exterior clean to avoid rust and damage to the finish. Don’t run into stationary solid objects. All those things that you generally can’t avoid when rallying, hahaha.
