Our featured post is clutch replacement on a 2010 Audi S4
While this article is about clutch replacement what inspired its writing was not the dual mass flywheel or modern clutch technology but the use of innovative weight saving materials related to this job.
Auto manufacturers are constantly looking for ways to save weight for improved fuel economy and engine performance. It only makes sense that shaving a few hundred pounds from the car will require less fuel, and that a 300 horsepower engine will move a lighter car much faster.
On many high end cars, aluminum frames and body metal are utilized; this is moving down to vehicles like the Ford F150 pickup which now utilizes an aluminum frame.
Our featured Audi certainly has aluminum in the body but it was while doing this clutch replacement that we saw some additional weight reduction features. First was the transmission to engine bolts which are made of aluminum. It’s quite bizarre to hold these large bolts in your hand: they are feather weight. From years of working on cars we definitely get a feel for the weight of a bolt and these are so light. Its like holding nothing.
The only disadvantage of these bolts is that they are one time use only. We notice this happening with more European cars, and for many jobs, bolts must be costed into the service.
The other weight reduction part that we noted from this job was the clutch slave cylinder which was made entirely of plastic. It too was feather weight.
These are just a couple examples of what manufacturers are doing to reduce weight. While the bolts and slave cylinder probable reduce the weight by a kilogram at most when these materials are used throughout the car the reduction can be impressive.
Clutch replacement on this Audi S4 is time consuming and expensive. As with most high end European cars many hours are required to remove the transmission and clutch, replace the parts and perform the reinstallation. It seems that German car makers just have a way of making things more complex than they need to be. This clutch utilizes a dual mass flywheel and there is no single mass conversion kit available. With all the labour involved in removing and reinstalling the transmission it makes no sense to risk not changing the flywheel at the same time as the clutch.
This Audi S4 is a beautiful car to drive: it’s handling is tight, the engine is agile and powerful and the manual transmission shifts beautifully. All of this expensive and complex clutch technology along with lightweight materials is just a small part of what make this happen.
For more about the Audi S4 click here https://en.wikipedia.org/wiki/Audi_S4
For an interesting study on vehicle weights and reduction options click here https://mitei.mit.edu/system/files/OTRin2035_Chapter-3.pdf