2017 Honda Ridgeline: Death Valley Post-Mortem
by Dan Edmunds, Director of Vehicle Testing
I wasn't working for Edmunds back in May 2005 when one of our staffers drove into Death Valley National Park to see the famous "sliding stones" that mysteriously move about the surface of a remote dry lake called the Racetrack. He drove a 2006 Ridgeline we'd just bought for our long-term fleet because it seemed like the right job for the new 4WD pickup.
The 54-mile round trip on the remote washboard dirt road to the Racetrack seemed to go well enough, but once he returned to pavement it became clear something was seriously wrong. All four shocks had given out, but the dealer refused to believe the damage wasn't the result of a badly landed jump or some other imagined type of abuse. The dealer eventually replaced them under warranty anyway, but with a "one-time-only goodwill" proviso.
Fast-forward to 2016 in San Antonio, Texas, where the 2017 Honda Ridgeline was introduced to the press. There I met an engineer who'd actually dealt with the aftermath of our 2005 Racetrack trip. Those blown shocks apparently made it into his group's hands, and what they learned was incorporated into the design requirements for this new second-generation truck.
With that in mind, we went back and repeated the journey with our 2017 Honda Ridgeline long-term truck. Along the way our Ridgeline's right rear shock developed a leak and lost effectiveness. But the other three dampers came through with flying colors, and the wounded shock wasn't completely dead.
Once it cooled and we got back onto pavement, it seemed to recover and do its paved-road job as well as it ever had. In fact, if we had been in pure tourist mode like the previous outing 12 years ago we might not have suspected anything had happened.
This was a huge improvement, even though one shock was a little worse for wear. In isolation, the result may have been dulled by a tinge of disappointment, but the other two trucks — our long-term 2016 Nissan Titan XD and 2016 Toyota Tacoma — that came along to support the effort fared much, much worse. Next to them, this seemed like a clear win.
The new 2017 Ridgeline has something the first-generation truck did not: amplitude reactive damping. In short, this means the new truck's shocks contain two internal valve circuits: one that operates when wheel motions are small and another that joins in as they grow larger.
This difference expands the performance envelope of the shock absorber. With this extra variable in play, the tuning engineer isn't forced to make as many compromises. Trust me, this is a big deal. I was the guy tuning shock valves in my last two jobs before coming to Edmunds. The process is a black art that boils down to managing compromises imposed by hardware limitations — particularly when you're tuning a truck, which is expected to work on a wide range of surfaces.
The precise details of how the second-generation Ridgeline engineers took advantage of this added functionality are not known to me, but I can hazard an educated guess. Our washboard road inputs, vicious as they were in terms of sheer unrelenting repetitiveness, were not terribly large — a little more than an inch at the tire. The shock, in turn, only experiences three-quarters of an inch or so because of its motion ratio, its specific mounting position along the length of the suspension's lower control arm.
It may well be that this amplitude was not sufficient to fully engage the second circuit at least some of the time. If so, this basically amounts to a bypass that allowed the shocks to flow with the surface rather than fight against it. On a surface like this, a little less damping force than you might otherwise want for a deep pothole strike might be just what the doctor ordered because damping force equals heat, and too much heat leads to shock absorber failures.
We might be able to guess where the line is drawn by studying why the left rear shock fared better than the right rear. Like many of its kind, this dirt road wasn't as wide as a paved two-lane road, so the left tire ran down the middle over waves shaped by two-way traffic. Meanwhile, the right tire ran closer to the edge where the waves could only be shaped by travel in a single direction. The left shock probably benefitted from waves that were less jagged, slightly shorter or possibly both.
Because it was still drivable, we called the dealer before we took it in. It would take five days to get the part. Without seeing the truck, the dealer couldn't tell us if it would be covered by warranty but agreed to order a shock and sort out the payment when we came in. To avoid the possibility of another five-day wait, we suggested the staff order both rears in case the left one had suffered some damage we couldn't yet sense or see.
After looking at the truck, the dealer agreed that the repairs would be covered by warranty. Moreover, it decided to change both shocks. Not because anything was wrong — the dealer confirmed there wasn't — but because Honda HQ had requested it so folks there could study the difference. They didn't know about our trip before we went, but they must have sniffed it out during the dealer visit. As with all warranty repairs, this one cost us nothing but time.
Since then we've driven our Ridgeline another 1,300 miles. It feels exactly the same as it did when it was new, and that's pretty much how it felt when we came off the road to the Racetrack and got back on normal pavement.
Dan Edmunds, manager of vehicle testing