Cover Story: Advanced Gasket Technology – Dry and Tight – Sealing Engines and Customer Loyalty
The effects of the interplay of materials, the physics of combustion and operating conditions are difficult to anticipate. Just ask the Ford Motor Company.; OEMs are bringing gasket companies into the design process earlier and demanding more, and gasket manufacturers are responding with more exotic composite gaskets.
Gaskets seldom receive the praise heaped on the modern technology of engines and their complex electronic controls. The gasket comes into play after a repair; it is seldom seen as the determinant of a successful repair. In short, the gasket gets no respect.
Yet few parts have been the subject of so much development over the past decade, and few parts have as wide-reaching impact on the success of a repair, than gaskets. The simple truth is that when you take something apart to fix it, you have to put it back together. And if it leaks afterward, no matter how adept the rest of the work, it will be deemed an utter failure by the customer.
Original equipment manufacturers (OEMs) have recognized the need to keep car owners’ driveways stain-free–lest they risk a stain on their reputation. What is seldom considered is how difficult it is to do just that.
Given the effects of the interplay of materials–the pairing of iron and aluminum in engines is now the rule rather than the exception–the physics of combustion and operating conditions are difficult to anticipate. Just ask the Ford Motor Company. In one of the most highly publicized sealing failures of recent times, its 3.8L V6 engine developed a problem with its head gasket after a design change to the engine in 1994.
The engine, which had found its way into virtually every top-selling model, became the subject of one of the most drawn-out customer service damage control initiatives of recent times. It wasn’t the only case of an automaker having to handle a premature sealing failure, but its persistence as a customer-satisfaction issue is astounding.
Ford had recognized there was a problem and issued a cylinder head torque procedure update to combat it, extended the warranty provisions in 1998, extended them further in 1999, then extended them again to cover more 1994 and 1995 models in 2000. As we reported in 1999: “Ford Motor Company, which had previously recognized a problem with the head gasket performance on its 3.8L V6, has extended the warranty to seven years or 160,000 km on certain models.
“The warranty affects the head gaskets used on the 1994 Lincoln Continental, 1994-1995 Ford Taurus and Mercury Sable, and 1995 Ford Windstar, and is the second time Ford has extended the warranty because of the problem. The original warranty extension, issued in 1998, was for 5 years/96,000 km for Taurus, Sable and Windstar vehicles, and 6 years/120,000 km on Continental. (The extension in 2000 included the 1994 and 1995 Ford Thunderbird and Mustang, and Mercury Cougar.)
“The problem stems from design changes to the engine for the 1994 and 1995 model years and is not, in fact, a problem with the gasket. Instead, according to Ford, it results from the different expansion rates of the aluminum and the steel head bolts. Under certain cold-start conditions, the head will actually lift off the block and then slam down repeatedly, until clamp load is restored–presumably when the components warm up. This repeated pounding causes bore grommet (fire ring) cracks. The original gasket, of a graphite design, wasn’t up to the pounding it was being subjected to. The replacement gasket is made of a higher density graphite to support the torque load better and more evenly.
“In addition to the gasket revisions, Ford had previously revised its torque procedures for the cylinder heads and offered a new bolt kit.”
Ford offered to help pay for failed engines, and even offered to help pay for a new Ford if customers couldn’t get a satisfactory repair done in short order. The whole ordeal must have cost millions of dollars, plus a lot of customer loyalty. It is a lesson learned by many OEMs, but which has spurred further development to achieve the no-leak engine.
“The biggest challenge is that the sealing systems in engines are lasting longer so it creates a challenge for the aftermarket,” says Raymond King, director of marketing for gaskets, oil seals and anti-friction bearings, Federal-Mogul Corporation. “We are seeing long life cycles. Most of the engines that were built in the ’90s are very realistically 150,000 mile (240,000 km) and better engines.”
OEMs are bringing gasket companies into the design process earlier and demanding more, and gasket manufacturers are responding with more exotic composite gaskets, replacing cork and fiber with molded rubber and steel-bodied constructions.
“And most of the domestic North American car makers, with the exception of GM, are using Multi-Layer Steel (MLS) gaskets. That’s a very sophisticated product, used mainly because the head and the block are getting lighter and lighter. So there’s more movement in bimetal engines and more of the weight being taken out.
“Taking total weight out of the vehicle gives them flexibility in the design of the engine; it can be put into a smaller space, but now you have parts that move around a lot more. The MLS gaskets are very forgiving.”
The challenge of sealing may have fallen to the gasket, and there may be a lot of technology at play to get it to seal for a decade, but the real world offers some real challenges. It’s a good news-bad news story, says Tom Gacioch, vice-president, marketing, Rol Manufacturing.
“The reliability and durability of the engines manufactured today is significantly better than 10 years ago, and a quantum leap from 20 years ago,” says Gacioch. “There is better engineering but the use of better products too, especially in sealing. Twenty years ago soft fibrous materials were common. It used to be that at (100,000 to 130,000 km) they would start to leak. These days an engine could run for (250,000 to 300,000 km ) and not leak at all.
“The bad news is that we’re not seeing the gaskets to repair minor leaks. The good news is that these engines are lasting (250,000 to 300,000 km ) and we’re seeing gasket sales due to catastrophic failures. Unit sales of gaskets are going down and that’s bad news for us, obviously. The good news is that a box of gaskets may have cost $15 to $20 years ago, but today they cost in excess of $100.”
He says that the materials and engineering are far superior–tooling up for a single MLS gasket design may cost upwards of half a million dollars, according to some estimates–but that doesn’t change the fact that some technicians may have difficulty making the transition; sticker shock has hit the gasket market, too.
Kevin Casey, in sales at Altrom Canada Corp.’s Toronto location, agrees. He says that he has noticed some surprise at the cost of newer-technology gasket sets, but that one of the key issues accompanying it is the variety of packaging options.
“At the installer level, I talk to many people and, depending on the brand, they include different pieces. They’re never really sure what they’re getting.”
In addition, he says, the proliferation of technologies has some installers confused.
“A lot of people have headed in different directions with gaskets, like head gaskets. Overall, there are people that want to make sure they get good quality, and the suppliers want to make sure that the installers follow the proper procedures.
“I don’t really know that the installers read all the literature that comes with gasket sets. Because of the different manufacturers and the different types of gaskets, there are different procedures. Just like everything, it’s a good idea to read the instructions.
“I see it more in the workforce now; with younger and younger technicians, everybody is under the gun to produce and they try to cut corners. You have to make sure that you perform the proper procedures or you’re going to end up with leaking–there’s no question about it.” With this in mind, a technical analyst for Rol Manufacturing wondered aloud at the time of the Ford 3.8L warranty extensions whether installers were going to remember the revised torque procedures at service time, or if the problem would continue as technicians continued to use outdated procedures.
“Sealing is getting much more technical,” says Casey. “And that’s why you can’t have your oil change guy replacing a head gasket.”
“One of the problems that the ins
tallers are seeing lately is the bimetal engines,” says Rick Pacyna, product specialist, Victor Reinz Gasket at Dana Canada Inc. The issue of surface finish on MLS gasket-equipped engines is paramount. “Basically you have from three to seven layers of metal in a sandwich, and that works in the same way. They can move around without tearing apart. These are being used for a lot of the bimetal engines because they do allow for a lot of movement, but the drawback is the surface finish.” Glass-smooth is the phrase he uses.
“A lot of people have to be wary, especially the machine shops. So if you have an imperfect finish, it is going to be very hard to seal. A lot of guys will take sandpaper to get the old gasket off, causing scratches. Depending on what material the gasket is made of, it might not be able to take up those scratches. With an MLS gasket, if you try that you’ll never get it to seal,” says Pacyna, adding that the gasket often shoulders the blame for the subsequent failure.
This necessity of using the proper procedures is an important message that the jobber can help deliver, says Allan Crosbie, marketing manager, engine controls, Dana Canada Inc. “We need to pass that message through, about sealing solutions and educating the end user on the proper procedures to use,” and on the options available, he adds.
“The 4.6 L Ford from 1991 to 1994 has an MLS gasket that requires an extremely smooth surface finish,” Pacyna offers as an example. “The block and cylinder head flatness are so critical that if the vehicle manufacturer’s surface finish specification is not adhered to, the gasket will fail. Dana went to a graphite gasket replacement to allow more tolerance for a less-than-perfect surface finish.
“The MLS is a great gasket. It accepts a lot more movement than any other type, but when you’re talking about a practical application, you can’t always get that factory surface finish. This provides an option.”
“The sophistication of these types of gaskets is amazing,” adds Crosbie. “You often think about the old cork gaskets, and now you look at the MLS and the different compounds,” he continues. “I don’t think a lot of people understand the technology that goes in; the science that goes behind dealing with these sealing issues and the development that goes into the replacement gaskets to compensate for engine wear and the field conditions.”
Somewhere in the midst of designing engines that will last a decade or more without spilling a drop, the consumer has become used to having a stain-free driveway. And, in a way, it has become the measure of a car’s prospects: a 10-year old car with a persistent leak is more likely to be consigned to Band-Aid solutions and an early grave than a dry-and-tight 15-year-old one.
Preventing or fixing a leak may be less common and require more technology than even a short time ago, but it is more important than ever.