Interior Insights: What You Need to Know When Installing Aftermarket Seat Belts

Jun 11, 2010

In the world of automotive interior work, seat belts are a must-have. Even if customers are only planning on trailering their cars to and from shows, not having the right kind of seat belts, or not having them properly mounted, is a liability issue for the vehicle owner and a serious safety issue.

For this column, I spoke with Steve Pekrul of Beam’s Industries, a seat belt manufacturer in Oklahoma City, about what auto trimmers and vehicle builders need to know when selecting, and installing, aftermarket seat belts.

Once you or your customer has decided that a vehicle needs new seat belts, the first step in selecting the right product is to know what standards those belts must meet.

Like the vast majority of vehicle safety equipment, seat belts are regulated by Federal Motor Vehicle Safety Standards, specifically standards 302 and 209. FMVSS 302 is the standard belts must meet for flammability and 209 lists the requirements for seat belt assemblies.

Trimmers and builders should check for a tag with those standards certified on them, Pekrul said. He added that beyond just checking for a tag, you should be able to obtain test data from the supplier. The company tests a percentage of all the components it receives in actual belts according to federal standards. These tests are performed to destruction to ensure the belts aren’t breaking under conditions less-stressful than those the standards specify.

“We record all of the measurements, when they break, before we even allow that particular product to be released for production,” Pekrul said.

Next, Pekrul explained that the hardware mounting kit for seat belts is important.

“You want to use at least a Grade 5 or better mounting hardware kit, which all of ours have to be to meet the strength requirements for FMVSS 209,” he said. “That should be something they do rather than just go down to the hardware store and buy some bolts that may not meet the strength requirements. Grade 5 or better bolts are strong enough and are heat-treated.”

He said that most of the seat belt installations he sees are done properly, but that it’s often difficult to tell whether a builder or trimmer mounted a belt properly.

“You’re probably not seeing how some of these people may be attaching the seat belts, whether it’s to a strong spot or not, if it’s going to the frame or not, that sort of thing,” Pekrul said.

“You may see that it’s mounted but you can’t tell that it was mounted properly because you don’t know what’s underneath the floor pan, whether it’s going directly to steel, etc.,” he added.

That said, Pekrul did praise builders for their technical savvy.

“[Builders] do a lot of good things,” he said. “They understand the safety aspects and will weld in [to] steel plates or across the frame to make their seat belt anchoring points stronger.”

Still, there are a number of questionable practices he sees. He pointed out that builders or trimmers who use more modern seats (he gave an example of a 1994 Cadillac) with integrated seat belts could be taking a risk.

That risk comes when these types of seats get mounted like a traditional seat that doesn’t have a seat belt integrated into it. The risk is due to the fact that the mounting points for a seat with seat belts integrated into it will see a much-greater force during a crash.

The risk can be reduced by ensuring that the mounting points for these seats are strong like seat belt mounting points.

One industry-wide issue that Beam’s Industries intends to address is the lack of available custom seat belts.

“There’s a great need in our industry for customization in seat belts: different lengths, different types of buckles and tongue combinations,” Pekrul said.

To combat this problem, Beam’s Industries recently launched a new website that will sell custom seat belts and seat belt mounting kits to builders, jobbers and auto trimmers.

In addition, Pekrul said that by the time you read this, the company will have started a seat belt refurbishing service available through the site

He added that the company’s engineers will evaluate the seat belts they receive for refurbishing to determine whether they can be salvaged. If not, the company will send the correct type of product back to the customer.