I don’t think the wheels are skipping. Bucking is the best description, with the front end dipping as the back raises, and vice versa. But the tires feel and sounds like they maintain contact with the ground.
The oscillations increase in amplitude as you drive over the affected pavement. On most of that road trip, the affected stretches of pavement were short, a couple hundred yards to a quarter of a mile perhaps. But there was a section that lasted for several miles, and it was then that the bucking became severe enough I had to pull off the highway.
I stiffened the DSC valves evenly (front and rear, high and low speed) two clicks, I think, then drove again. It was a little better, but still a problem, so I pulled off again and stiffened the rear another click on the high speed, and 2-3 more clicks on the load speed. I’ll admit I didn’t really know if these were the right adjustments to make, but it lessened the bucking and it felt safe driving on that pavement again.
If you’ve ever ridden a full suspension mountain bike with the rebound set too fast, this feels somewhat similar to that. The Fox DSC shocks don’t have an adjustable rebound, and I’m far from a truck suspension expert, but it sure feels to me like the rebound is not right.
I come to that conclusion mostly because of the tendency for the oscillations to increase in amplitude the more lines/cracks in the pavement I drive over. Each previous line adds to the up/down movement coming from the next line.
I plan on talking to the off-road shop that installed my shocks, not that I think they did something wrong, but because I hope they’ll have some advice and experience with suspension issues like this. (They did not, incidentally, pick the components; I did that and had them install). What’s kept me from doing that so far is that it’s tricky to explain (as you might have gathered by my long reply), and that I’ve only run into this issue once in the Atlanta metro area where I live. I probably can’t ask the folks at the shop to drive out to South Dakota with me.
And even then, that stretch of highway was on the opposite end of town.
In other words, I’ve got to find some local stretch of road that exhibits the problem. If I can’t do that, I’ll just give them a call and maybe my awkward description will be enough to trigger some ideas.
Oh, I will consider upgrading the control arms, though. Too bad I missed the sale Core 4x4 just had.
