The other day I had the opportunity to drive a new 2015 Ford F-250 pickup. With the sheer variety in cab and bed configurations available on pickups these days, saying what it is often doesn’t paint the entire picture. This particular example was four-wheel drive, with an extended cab, and the 8′ bed. It was powered by the standard 6.2 liter V8.
Despite its sheer presence, it was quite easy to drive. It rode like a Lincoln of yore on smooth pavements. Then it happened. An occurrence I have experienced before with a few other vehicles, it is irksome despite it being a natural phenomena. On concrete pavements having joint spacings of both 15′ and 30′, the spacings conspired with the 158″ (401 cm) wheelbase of this pickup to cause a harmonic that will shake any extra insulation one keeps around their midsection.
I have experienced it in an extended cab 2007 Chevrolet Silverado and to a lesser degree my 2007 Ford F-150. In each of these instances, the wheelbase is longer than the norm.
So, the question: What vehicle(s) have you driven that demonstrated unorthodox behavior in some situations? What was the vehicle and what was the situation?
My 1946 Willys would develop an up/down oscillation on some pavements that were not flat. It felt like riding a quad on whoopdie-doos only at a much faster speed. It creates a bucking motion.
My 1994 Wrangler has done it, but not near as often or as badly. The Willys felt like a bucking horse on the one road I was on.
My Samurai would do this, too.
Did that feel like the car was bending in the middle?
My 2007 BMW X3 did exactly the same. Despite being many times more expensive than Willys and Samurai…. 🙁
A late 70s model full time 4×4 Suburban my dad used for a work vehicle. It’s wheelbase lined up perfectly on Colorado’s suspension bridge sections to give quite a ride. I remember it well.
I assume the bed was empty? The ride will improve with some cargo.
It wasn’t a load issue; there were several hundred pounds in the bed.
I assume the bed was empty? The ride will improve with some cargo.
I used to see a pickup ad on the tube that always cracked me up. Two trucks running side to side, one on a dirt road, one running on a railroad bed. One view showed how violently the tires were bouncing over the railroad ties, but the front view of the two trucks showed the one on the railroad bed riding about as smooth as the one on the dirt road. At the end of the ad, the two trucks passed under the camera, and you got a fleeting glimps of the beds of the trucks. The one on the dirt road was empty, while the one on the railroad bed was loaded with bails of hay.
Just older vehicles for me. I had a Ducati 450 Jupiter that I bought used. The first time I got it above 80 mph it started to oscillate side to side like a metronome. Pretty scary. I guess the frame must have been bent. Never drove it again above 75 mph. My high mileage ’63 Valiant was unneccessarily equipped with the numb Mopar power steering that contributed to an over correction jamboree when I swerved to miss a groundhog. I couldn’t get it back on a straight line for more than half a mile, and a lady going the other way spun out rather than get sideswiped. I drove back to check on her, and all she could say was, “Next time, let the groundhog DIE!”.
These days, that would probably be grounds for a recall!
A Saturn SC2 that would drive perfectly normal up to 68 miles per hour…then shake violently between 69 and 77, then go back to normal.
“So you see, Officer, I have to speed.”
I eventually got underneath the car and determined that I had clobbered the subframe so hard that the wheelbase on one side of the car was an inch shorter than on the other side. Maybe that was it.
Are you sure you weren’t driving a Renault?
When I lived in California I was told certain freeways around L.A. could set off a porpoising action in some cars, but I never experienced it.
I did have a friend who could not ride very far in my 80 Fiesta, when we drove around the San Jose area, without falling asleep. Something about the gentle rocking up and down caused by the slabs of freeway concrete would have him nodding off in no time.
Right now, as you cross from Georgia into South Carolina, you get concrete slab interstates that are annoying to ride on as they are somewhat jarring forward and back as well as side to side.
I suspect the newness of your truck also had some impact (no pun intended) on the ride.
Those must be murder on shock absorbers.
… certain freeways around L.A. could set off a porpoising action in some cars,
I recall Motor Trend test reports in the 70s noting a car’s susceptibility to “freeway hop”. If I recall, MT laid it to LA using thinner concrete, because they don’t have the repeating freeze/thaw cycles that tear up Michigan roads. The thinner slabs would sag in the middle, leaving the edges of the slabs higher, imparting a rhythmic up/down motion on the car. With the weak shocks that were common at that time, the suspension couldn’t damp out the motion, so the car would bound from slab to slab.
We’ve got that in Houston on a few highways. Can be fun….
18 passenger Dodge full-size van, pulling a trailer on which I had loaded an F-150 parts truck. I apparently had the center of balance off, because when we pulled on the interstate and accelerated past 45mph, the whole shebang started severely oscillating sideways back and forth. Finally got it under control, but had to iron the seat covers back flat when we got home.
My old ’69 F-100 suffered from horrible bump steer (“Twin I-beam suspension!), and I had to be super careful at certain known spots on our poor roads around here. My ’99 F-250 does the same thing, only at the rear end (unloaded) – hit the wrong pothole at the wrong speed and the back end suddenly wants to be out front.
Had a 510 on a tow dolly behind my Nissan truck once that began oscillating wildly at 90km/hr. We moved the two extra rims and tires plus the spare out of the trunk and put an extra 10psi in the back tires and this bought an extra 20km/hr. We figured it was the radial tires on the tow dolly and bias ply snows on the car that was the root of the problem. The gusty crosswind didn’t help much either. The trick was to catch it when the car began to sway and accelerate to pull it straight without going over the magic speed. It was a long uneventful drive after figuring out the dynamics of the rig.
It’s been a long time, but certain sections of Los Angeles area freeways, the concrete ones, did seem to set up harmonics that would make my long bed single cab Chevy pu start to ‘buck’ in the center, like it was hinged in the middle. It must of been some kind of surface irregularity that affected some vehicles more than others. The same section in my VW would only be a gentle motion. I’m thinking it was 134 freeway heading from Glendale toward San Fernando Valley, but it was so long ago it may have been on a different freeway.
I can tell of a TRAIN that did it. In the early 1990s, Amtrak experimented with Spanish Talgo trains in the Pacific Northwest. They rode fine on welded rail but in 1995 a route between Seattle and Vancouver BC was revived, and that route had the older, jointed rail. The bolted-together rail sections were a standard 40 ft. long…close enough to the single-axle “wheelbase” of the articulated sections of the Talgo train that they caused exactly that “porpoising” at just the “wrong” speed. I was on the first trip of the revived service (it had been discontinued in the 1970s and in any case the old trains used streamliner equipment with four-wheel trucks spaced farther apart) and officials said that with an empty train on test trips, the resonance of the suspension differed so the problem did not show up. Over the years the track was eventually rebuilt with jointed rail; until then certain speeds had to be avoided.
My father had two XJ Cherokees, a first-year ’84 and a ’90, that I spent quite a bit of time in. Both vehicles exhibited unusual side-to-side movements on bumpy pavement, like it was rotating on its roll-center. I always attributed it to the solid axles.
Do they have Panhard rods?
I recall some late-60s perimeter frame cars were highly susceptible to that phenomenon. One of the magazines (Hot Rod?) even speculated that was the real reason GM moved from the 115-inch wheelbase to the 112/118-inch split — to avoid that harmonic range. (I don’t know that that’s true, but that was their speculation.)
I’ve never run into that specifically, although certainly the freeway surfaces produce other annoyances, especially at certain speeds. My pet peeve is the way the longitudinal grooves in some sections of freeway will cause some mild but very disconcerting lateral weaving, which is more pronounced the higher the outside temperatures are. (I don’t know if it’s that the ridges become pronounced due to heat expansion or that when tires are warmer the rubber is more apt to stick to them or a little of both.)
My ’02 Ford Super Duty is the same configuration as the feature. Never had the bucking motion, but it sometimes oscillates severely at speeds above 70 MPH on the 405 freeway.
a while back, I worked for a supplier to (then) DaimlerChrysler. One glorious weekend, I was entrusted with the keys to a soon-to-be launched 2003 Viper. You know, back when 500 hp was news.
On smooth roads, that car was a dream. If you were stupid enough to drive it on a road with rain grooves, or an asphalt road which had ruts worn into it, that thing would tramline so badly it’d threaten to rip the steering wheel out of your hands.
Man, you just made me remember the old bias-ply tires I initially had on my Vega. Same deal – you really had to watch your track on certain roads. My first set of radials (ever) were a revelation (Michelin XZX).
this happens to me now in my falcon as I approach intersections under breaking where trucks have carved those grooves.
My ’00 Wrangler was experiencing horrible death wobble when I first got it in ’03. 99.9 % of the time, this jacked up beast drove like a dream considering what a nasty looking rig it was. But hit a bump the wrong way and it would violently rip the wheel out of your hand as the front end wobbled in a reciprocating action. The 2″ BDS lift and 33″ BFGs on 15×10 deep dish wheels were what I thought to be instigating the problem…turns out the track bar bushing had turned to goo from some spilled motor oil. I replaced it with a $6 urethane piece from Energy suspension, and upgraded to a heavy duty steering stabilizer. Problem solved for the entire 10 year span I had it.
At freeway speeds, all short wheelbase Jeeps are a bit skittish even on perfect roads. Add a lift kit and bigger tires and it magnifies this…even though mine was only 2″, a quality name brand kit, and professionally installed. For the other Oregonians on here, if you’ve ever come up I5 north, the center lane between Salem and Woodburn was horribly rutted out from the traffic. Well the track on my Jeep was a good 6-8″ wider than stock due to the tires I had with wide offset wheels, meaning it could never really center itself in those ruts, rather riding on the outer edges of the tires. I learned to avoid all but the fast lane when coming home from Roseburg when I had an ex g/f down there. More than once I redeyed that trip first thing Monday morning after leaving her place to get to work and man you DONT want to be half asleep fighting an unruly Jeep at 70mph!
They have been fixing the worst parts of I-5 in Oregon lately (very slowly), it’s not as bad as it was. That section you described was horrible in the rain, cars would hydroplane terribly on it. Oregon is very bad on setting up “work zones” that never seem to get any work done, they just set up cones and call it good for a year or two. I suspect it’s revenue enhancement.
I’ve experienced some very odd porpoising in our ’12 Forte Koup, which is odd given its wheelbase isn’t especially long (104″). It only seems to happen on certain bridges, most noticeably on the three mile long Wright Memorial Bridge headed toward the Outer Banks in North Carolina. I was probably doing 70-75 MPH and it got so “bouncy” that I slowed down out of an irrational fear that I’d fly off the pavement… And the car usually has quite mild road manners.
Well first off I grew up in the Southern Tier of New York so I have heard stories of city cars like the Honda Fit and Scion XB behaving terribly and/or getting damaged on really rough asphalt roads or rutted dirt roads that are not even seasonal. Some cars with thin sidewall sport tires have also had a problem with dented rims or blown tires or poor handling on anything that was not smooth asphalt. I do remember that back in November 2008 driving a 15 passenger Chevy Express 3500 from Texas to Louisiana on I-20 was no fun (especially for the rear most passengers) because as soon as you entered Louisiana the Van would start porpoising so the drivers just stuck to the left lane which is smoother. The bridges in New Orleans would also make the Vans behave that way, but the operators and passengers in the 15 passenger Ford Econoline 350s had it even worse due to that Van’s large Badonkadonk.
I had an 87 Caprice that would drive itself into right hand side ditches if I let go of the wheel. I once managed to negotiate a curve nearly the whole way without holding onto the steering wheel. My 1995 Voyager would experience a squirrelly rear end if I did not have much weight in the back and I was driving (too) fast on a rough road. Now that I live in Portland, OR with an 03 Caravan I have yet to find a handling quirk with my Caravan. Sure it only has 150 HP so going up hills or mountains at or near the speed limit is usually out of the question, but that is to be expected.
” Some cars with thin sidewall sport tires have also had a problem with dented rims or blown tires or poor handling on anything that was not smooth asphalt.”
HA! Id like to see how the donkers handle our snow and ice up here in the land of no salt! Luckily, I see a lot more beefed up Jeeps and 4x4s than donks.
My 133″ wheelbase Ford F-150 has similar “trouble”. I put a 800 pound slide in camper in the bed and now, loaded, it drives like it ought to.
The road is always putting vibration to the chassis. The frequency of that input is directly related to the vehicle’s speed.
What may have happened here is that whatever frequency was there matched one of the resonances of the structure. Which is not good at all. Some weight may help as it would modify the value of the natural frequencies involved.
Has this happened to you at any speed or just one particular range? What was the value?
I drove this particular pickup around 180 miles, with me and one other person. There were two loaded toolboxes mounted to the bed rails. The pickup had 2,500 miles and wore highway biased tread tires. The harmonic was at speeds from 60 to 75 mph. It did increase somewhat with speed, but not as much as expected. Joint spacing (15′ and 30′) did not seem to affect it however, 60′ joint spacing did not pose near the issue.
The road where I drove this pickup is one I have not experienced the issue as much in the ’07 Silverado. The Silverado is typically unloaded; I have had a more pronounced issue with it elsewhere.
Sometime ago I talked to a gentleman I know how works extensively with concrete pavement. We were in the Silverado on a section that is particularly pronounced for it. He stated that this is a typical problem with longer than standard wheelbase pickups and it has been discussed on a nationwide committee in which he serves (AASHTO – American Association of State Highway and Transportation Officials). He said it’s simply tough to get a joint spacing that accommodates all vehicles and the small to large sedan wheelbase is the typical design vehicle.
Perhaps they should look at varying the spacing then, similar to how the blades on a radiator fan are irregularly spaced to avoid harmonics.
I lived in north central Nevada in the early eighties and made a few trips to Salt Lake City via I-80. It was basically impossible to drive in the slow lane in my little Datsun–the ruts were so bad you would just get hurled from side to side. What a steering wheel wrestling match that was!
Damned annoying, and the only solution was the fast lane. In my slow-ass Datsun….
Yep, left lane bandit right here, and I did not care.
I forgot to mention Id bought that ’00 Wrangler when I still lived in Memphis. Coming off the freeway Id take a left to get to my old apartment. If it was fresh rain the pavement would be good and slick and I rarely kept the rear seat in, lightening up what was already a noseheavy rig. If I hit that left turn with just mild speed, Id downshift into 3rd, blip the throttle and slide around that turn every time! Quite a few times I even got it to do a perfect strafe sideways into the outer lane before recovering and taking off with a little fishtail. The 4.0 is great fun around town…out on the open road, not so much.
I’m trying to remember if any of our cars had freeway resonance issues, but maybe I’m blanking on anything that happened. I do remember, though, that both our ’93 Sable and our ’03 Civic Hybrid seemed to go out of balance all too easily, and then driving them on the interstate was no fun, especially at 75 mph. Oddly, our ’09 Camry Hybrid is smooth as silk at freeway speeds, and the wheels never seem to go out of balance.
My glorious Nissan Laurel develops an interesting up&down wheel oscillation but only in specific (and repeatable) circumstances: when being cornered enthusiastically uphill on gravel roads. It only needs a few corrugations across the road to get the oscillation started – always on the inside (and thus unloaded) front wheel. The oscillations continue well after the corrugations have stopped. I imagine from the outside the wheel’s bouncing like a pogo stick. But nothing beats driving a RWD car enthusiastically on gravel, so I live with it!
RWD and gravel is the best combination to sharpen ones driving skills all while providing excitement at somewhat lower speeds. It’s the best of both worlds.
That is why corrugations gradually grow over time, both the height and number/length. Do you still have the JDM shocks I wonder?
Corrugations are something I don’t like, you have to chose either a slow speed so your car doesn’t get shaken to death or go fast enough to skip across the tops and hope you don’t need to make any sudden steering or braking inputs because your tyres are only touching the ground about 15% of the time, and that is after you have passed the resonant-frequency speed where in 1980s cars you would see the dashboard shaking a couple of inches up and down.
These would be the sort of conditions that saw the first Opel based Holden Commodore prototypes fail, the shock towers tore out of the car and I gather not at a welded joint. No rust-induced weakness as experienced in a US salt-using area either on a brand new prototype!
Yes, original JDM front shocks, still pass our 6-monthly roadworthiness inspection but are finally getting soft (after 17 years and 330,000km). The JDM rear shock made it to 15 years and 240,000km before giving up the ghost.
My litmus test for currugation speed is the sweet point where the frameless door glass stops squeaking on the seals, and before they start again! And the other litmus test is focussing on how much the wheel alignment will cost!
I-5 Northbound just past the Tacoma Dome has a bend first to the right, then to the left. And of course, the left hand bend has a nice offset height seam in the center-right lane. With a live rear axle (Panther love!) the back end of the car jumps a few inches to the side. Wakes you up right quick. I’ve subsequently learned to be in a different lane through that section.
My 85 GLC had a slightly different vice, really soft mounts on the powertrain. iirc, there was one big mount on each end, nothing on the sides of the engine and trans, so they could rock forward and backward. Once in a while, I wouldn’t quite wind the engine up enough before engaging the clutch. The engine would rock one way as the clutch engaged, then the engine would bog, just as the car started moving, which pushed the engine the other way, then the engine would catch, and rock the other way again as it applied torque, then it would bog again. Once the powertrain started it’s front to back oscillation, I had to release the clutch and wait for it to calm down, before trying again. Never had that problem with any stick shift Honda or Renault.
My first car (1990 Peugeot 205 Roland Garros) had something similar, and now I know that it was because of a previous accident. The car shook between 100 and 120 km/h… If I rode slower or faster, the car would be smooth as silk.
But there was no centre console problem?
There was no center console at all – the way God and Henry Ford intended! In that rig, I could sit with my legs crossed without hitting anything. It was great.
If I had it my way, no full-size truck (SUV or pickup) would even be available with anything besides a flip-down console bench seat.
Luckily, I don’t.
It was folded up on this one; the cupholders weren’t big enough so something different had been done to it.
My old Seville STS had an annoying torque steer problem. It actually had a bit of a learning curve to actually keep it on the road (not to mention a singe lane) under full throttle.
At first when i bought the Expedition it floated all around in road surface grooves.. it was impossible to keep it in a straight line even on dry roads. After i switched to slightly less used tires from a different manufacturer and 5% higher sidewall in the front and the issue was gone.
Also one general problem is the horrendous turning circle with the large FWD cars. especially compared to full-size 4WD SUVs. The Expedition feels nimble compared to the battleship-like Seville. I once did a U-tun on a 4-lane and despite having the steering wheel to the very end could not avoid the curb on the side of the right lane.
Rented a cube van once to go empty a house. It was a brand new Ford with abs and less than 3000km on the dial. There was about 1cm of fresh snow on the ground and I was almost stopped at the first stop sign when the abs kicked in and prevented the truck from stopping. Lucky it was 7am on a Sunday morning so no traffic on the cross street so I ran the stop at half walking speed with the abs groaning. Same fresh snow on the street where the house was located so I stopped before each sign without triggering the abs and idled up to the stop. At least the sun came out while loading up the truck and dried up the road. I’m sure it would have behaved differently with a load in the truck but I would rather not find out it was worse.
heavy truck tires are almost universally terrible in snow.
My 72 F100 short wheel base would do that sometimes. Between the twin I beam / leaf spring suspension and that old bench seat, I’d have to tighten my lap belt to keep from hitting the roof. It was most notable on I-20 just west of Jackson, MS.
Toyota Yaris. It handles like an old French car – buckets of body lean but it WILL hold on! (at least with 44 PSI in the tires it will)
One reason those fair better on roughed up Central New York roads than Fits.
My ’97 Escort would “porpoise” at certain speeds and it was caused by expansion joints. One of only two things I disliked about that car, the other being the ridiculously tiny door openings. Come to think of it, my ’97 Wrangler did the same thing.
During a severe storm in january 1990 my 1982 Renault 5 (Le Car / The Voiture) wouldn’t go beyond 50 mph. No matter how hard I, or it, tried.
That’s routine in an R5. Even though mine had the big 1.4L, desmogged to US spec, top speed depended on which way the wind was blowing. With a tail wind, it could cruise at 80. With a headwind, it topped out at 55. One day with less of a headwind, I tried to pass a semi. I was overhauling the truck just fine until I hit the bow wave coming off the truck. Try as it might, with the gas pedal floored, it couldn’t penetrate that wall of air. Finally we started pulling a hill, the truck fell back and the R5 finally managed to break through.
You had the Big Block. I had 845 cc.
meanwhile, someone on Jalopnik called the 325 hp Ecoboost F-150 “underpowered.”
o_O
Learn how to anticipate in traffic and how to use a stick properly. The main advantages of tiny engines. Everything after that with more power comes as a revelation. Even if it is a grey metallic 1987 Ford Escort One-Point-Four. With 75 hp IIRC.
Learn how to anticipate in traffic and how to use a stick properly.
In the R5, I called it “conservation of momentum”
It was happened with my grandpa’s samurai, few years back. but no one of us got the actual reason for it that time.
Death wobble! That’s EXACTLY what plagued the ’00 Ford Explorer I used to have. I took it back to the dealer 4 times just for this (among many other problems, I don’t miss this vehicle AT ALL) and they just could never find anything wrong with it. FInally, one day on the way home from work it started the shuddering again, and before I knew it, it was on it’s side in the median… One of the front wheels tore right off, and it cartwheeled up against the median divider. Nobody was hurt, fortunately. I was in rush-hour traffic going 60mph or so, so this could definitely have turned out SO much worse. But at least now I know what to call the shuddering, shaking feeling it made. Eesh, I hadn’t thought of this for years, until I read this article… I also wanna add that this vehicle was less than 2 years old when the accident happened, and had only ever been used for commuting between a suburb and downtown, so no crazy off-road damage or anything.