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LEADERS: Talking 6x2s, disc brakes and downspeeding with Meritor’s head engineer

LOUISVILLE, Ky. -- Are 6x2 axle configurations coming to Canada in any significant way? Is interest in air disc brakes cooling? How are the new reduced stopping distance (RSD)-compliant brakes performing in the field? And what other trends are...

LOUISVILLE, Ky. — Are 6×2 axle configurations coming to Canada in any significant way? Is interest in air disc brakes cooling? How are the new reduced stopping distance (RSD)-compliant brakes performing in the field? And what other trends are driving component suppliers?

These were a few of the questions I had the opportunity to present to senior executives with Meritor, during an exclusive interview with Jay Craig, senior vice-president and president, commercial truck and industrial, and Joe ElBehairy, the company’s vice-president of engineering and quality.


TN: Jay, how is the market shaping up for Meritor this year and for the industry as a whole?

Craig: What we see for the rest of the year is very, very strong. What we’re hearing, even today from customers walking around the (Mid-America Trucking) show, is the market seems strong.

The good thing about this upturn compared to previous ones – especially the last one – is there is no regulatory deadline looming, so we’re all hopeful production can be much more rational.

TN: Do you have any concerns about production capacity and being able to secure the raw materials you need?

Craig: No, I think we’ve planned for it and we feel very well prepared. Any time you get a spike like this, you tend to see some commodities that tend to run away a bit, but overall we feel very good about it.

TN: Joe, one of the themes at this year’s show has been fuel economy and one of the ways OEMs are improving fuel economy is through engine downspeeding. But this places some additional strain on downstream components, doesn’t it?

ElBehairy: There’s more torque that goes through the driveline because of the startability. In order to have an acceptable level of startability, the engine torque and drivetrain torques are increased. What customers need to understand and look at is the drivetrain system, starting with the engine, what powertrain protection technologies are enabled in the engine is really critical to making sure that as they go faster, they’re not overloading the rest of the system. But then beyond that, they need to make sure the transmission, driveshaft and axle are all linked up in terms of those torques that go through the system.

TN: How does this impact the spec’ing process?

ElBehairy: Customers have to look at things a little bit differently. They have to understand the technologies and how things interact more than they used to; there’s just a lot more interaction between the engine, transmission and the axle than their used to be.

Where I think some fleets get into trouble is when they don’t coordinate the selection of those components or those systems properly, and they have a less than optimized system. So what you see OEMs trying to drive are unique configurations that are better tuned to drive fleets into more optimal solutions.

TN: There continues to be a lot of talk about 6×2 axle configurations. Will this ever be a mainstream spec’ or will it always be a niche market?

ElBehairy: The technology is there that should enable them to become mainstream from a functional standpoint. We’ve developed systems that are every bit as functional as a 6×4 and we’ve demonstrated them to skeptical fleets. You have a roughly 400-lb weight savings going to a 6×2, you have comparable traction and you have a 2-3% fuel economy advantage just because of the loss reduction that you have by eliminating the gear sets.

I think all the technological enablers are there, but it’s a matter of changing peoples’ mindsets and fleet buying habits. I think it will come – the question is how fast? Boldly, I’ll say yes, it will be mainstream in the next five years, but we’ve said that about a lot of technologies that haven’t made it yet. But the technology is there.

TN: You mentioned skeptical fleets – that must be especially true in Canada. Will we see the 6×2 trend spread up into Canada?

ElBehairy: There are several provinces that don’t allow it today. We have been working with a mini-consortium to try to address some of the challenges in Canada and the two (provinces) that are really resisting this right now are Quebec and Ontario.

Specifically, it’s the load shift technology that is necessary to enable traction. They don’t allow it because their concern is, there’s nothing to control it from being done full-time and not just in a traction event.

TN: But why would a driver do that?

ElBehairy: In an extreme situation where you can lift the axle and turn it into a 4×2 – that’s the extreme of a 6×2 with load shift – somebody could do that (raise the axle when loaded) for fuel economy reasons. That’s what we’re discussing with both Ontario and Quebec, but that’s really the limitation we have right now. The other provinces have agreed with us and are okay in accepting it; it’s those two that have stepped back. This is recent, within the last couple of weeks. We’re going to keep pushing.

TN: Moving to brakes, have there been any issues in the field with the reduced stopping distance (RSD) brakes?

ElBehairy: The brakes are performing very well. The things we’re looking at for RSD is the aftermarket cycles, making sure people replace them with stopping distance-compliant friction so they don’t reduce the safety that was the whole purpose of the brake.

One thing we’re seeing a little bit of, is there’s more braking force on the front end of the truck now. The OEMs and brake manufacturers are working through that to try to tune things to make sure that’s not an issue, but by and large, it’s been very successful.

TN: I heard it said recently that you shouldn’t feather RSD brakes, that they are formulated to work. Would you agree?

ElBehairy: I wouldn’t disagree. When you baby a brake, you have a tendency to allow it to glaze and that could impact its performance when you need it. So the challenge is, though the brakes were designed in extreme braking situations to (stop shorter) – most of the OEMs drove about a 225-ft. stopping distance, about a 10% margin to the regulation – the reality is drivers are still stopping at the same braking speed they did before RSD, they just have a lot more brake force if they need it.

As a percentage of absolute power available, what they’re using is probably a lower percentage than they used to, so I wouldn’t disagree. It’s not a cause for concern, but don’t be afraid to use the brakes that are there.

TN: Besides compromising stopping distances, what other risks are involved in using non-RSD aftermarket friction?

ElBehairy: If you put a friction in that wasn’t developed for that brake system, you have noise concerns, you can have friction swell, pad swell and other issues like that, that would be concerning. You might have premature wear on your drums. Those things are all certainly possible.

TN: Are you continuing to see increased demand for air disc brakes or has it cooled off?

ElBehairy: The short answer is yes, we see continued adoption. It’s steady but it’s still slow, on an order of 1-2% per year increase, which isn’t insignificant. We see more OEMs planning for standard position platforms with air disc brakes. Obviously there’s an upcharge, it’s a premium technology.

TN: Drum brakes have gotten better as a result of the reduced stopping distance requirements. Has that slowed the adoption rate for disc brakes?

ElBehairy: No question about it. When the RSD regulations came out, I think the original view was the majority of the applications would be driv
en to disc brakes. The reality is drum brakes evolved. I think that has been a bit of a challenge for disc brake adoption and rightfully so.

At the end of the day, fleets have to make a purchase decision based on total economics: acquisition price, service, maintenance, ease of use, drivers, safety – all those parameters are part of the equation.

TN: Besides downspeeding, 6×2 axles and disc brakes, what other trends are you seeing that affect – or can be affected by – Meritor?

ElBehairy: Lightweighting. There’s always a double-edged sword when it comes to lightweighting because there’s usually a cost impact that goes with it and the majority of vehicle platforms aren’t willing to pay a premium for lightweighting. As a result, we can’t apply those economies of scale and make further advances. If 80% of the market was going after lightweighting, imagine the scale you’d have and the cost reduction you’d get from doing that. So that’s a big challenge.

The other thing you’ll see is more focus on vehicle dynamics, specifically suspension integration. A Class 8 truck is not typically thought of in the context of handling, but one OEM is developing a rear suspension that’s targeted at increasing roll stiffness. You wouldn’t inherently think about that, but we see that as a trend.

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1 Comment » for LEADERS: Talking 6x2s, disc brakes and downspeeding with Meritor’s head engineer
  1. Mike Pennington says:

    Great reporting. Again, James “found” the story and got some insights from Meritor’s Elbehairy. Well done!!!

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