SVT Enthusiast discussed the pros and cons of changing engine drive pulleys to help enhance power and performance. The story noted that one of the drawbacks to such an aftermarket modification is the possible effect it would have on the owner's New Vehicle Limited Warranty. When SVT's own Tom Scarpello read the story, he felt that the whole vehicle modification vs. warranty issue is one that deserves a little more than a cursory explanation, especially to performance-savvy SVT vehicle owners. So he asked Joe Bradley, the Manager of Ford's Warranty Analysis department, to add a little perspective on how certain vehicle modifications can affect the service life of some factory parts or systems, and how that may subsequently affect the factory vehicle warranty. The following is Joe's report.

As you might expect from the company that formed SVT, the Ford Motor Company has many employees who are true performance enthusiasts -- folks who love and care for their personal high-performance vehicles as much as or more than the next guy or gal. Many of us, in fact, are true "weekend warriors" who can be found at the local drag strip or road course on Saturdays and Sundays, and tinkering under the hood during weekday evenings getting ready for the next event. As automotive enthusiasts, we certainly can appreciate performance machinery.

That said, as Ford employees we all want to do the right thing for our customers as well as for the Ford Motor Company. That is precisely why it is important to have a concise, easy-to-understand policy with regard to Ford warranty administration. For vehicles that are not modified, the Ford warranty policy is clear – the company backs its products within the guidelines of the new vehicle limited warranty, which is designed to protect the customer from defects in factory workmanship and/or material.

However, in the case of vehicles that have been modified, one needs to understand that the modifications may affect warranty coverage. This is simply because any damage or failure of new vehicle components or systems that was caused by modifications to the vehicle are not defects in "factory supplied" workmanship or material.

To illustrate this point, let's consider a small sample of vehicle modifications and see how they might affect factory components or systems:

When it comes to changing the factory engine drive pulleys, there are some powertrain system and component concerns that deserve consideration. One would be any electrical and/or charging system problems that arise because of reduced alternator operating speed caused by the installation of underdrive pulleys. After all, the performance and serviceability of many system components are based on certain design parameters that include operating speed. The same goes for problems stemming from higher cooling system temperatures because of reduced water pump

flow caused by the installation of underdrive pulleys. Increased underhood temperatures caused by owner-induced changes to a factory design-specification part can have a detrimental effect on any number of powertrain components or systems – some that may have long-range implications. And things can get even more serious when supercharger pulley changes are made, including head gasket leaks and piston and connecting rod failures. Also possible is piston damage due to detonation from improper air/fuel and timing modifications.

The installation of any non-factory forced induction system can also cause problems. Base engines modified with aftermarket superchargers, turbochargers or nitrous oxide injection systems may indeed bring about some power gains, but they can cause piston, connecting rod and/or crankshaft failures as well.

Other parts of a vehicle's factory-spec drivetrain are also susceptible to damage when engine torque and horsepower is increased. Performance chips or other power-enhancing devices increase torque loads on the driveline and can force failure of the transmission and/or rear axle. The latter problem can be especially true when owners switch to wider tires or racing slicks in an effort to increase traction. Even non "go-fast" aftermarket accessories such as remote starters, alarms, supplementary gauges and audio equipment can cause electrical system service problems if they are installed incorrectly or have improper connections.

When it comes to fairly evaluating the possibility of a warranty denial, there's one simple rule of thumb to follow: Although the installation of non-Ford parts and aftermarket modifications, by themselves, will not void the Ford New Vehicle Limited Warranty, failures that result from these parts and/or modifications may result in a denial of warranty coverage for such failures or damage.

The bottom line is, Ford Motor Company wants each of its owners to enjoy their product to the fullest extent – and that includes performance vehicles. But dealer service technicians have seen, and continue to see, that modifications may cause the original design to fail. The addition of aftermarket parts is a risk that each and every vehicle owner must evaluate for themselves. All that's needed is a reasonable dose of common sense. When and if you modify your vehicle, please consider whether the modification may cause another component to fail – and if it does, recognize that warranty coverage for that failure or damage will likely be denied.