Fleet Tacoma Bucking/Shuddering/Bouncing

[Squatch]

A couple of weeks ago I had this happen to me in the 1st gen Tundra with Eagle camper. The 1st time ever on I-81 north in PA. The truck bounce was so beat into the pavement that my truck synced up and started bouncing in sympathy with the road. 1st time I've ever had this happen that bad in any truck. Slowing down and changing lanes helped. I have E rated Tires at 45/55 psi and I run my air bags around 26-30. Normally even on bad roads it drives and handles like a dream. That has got to be the worst section of truck imprinted roadway I have ever encountered though. I looked at a flatbed towing a 5th wheel next to me and it was bouncing so bad the bed was flapping.
I'll be upgrading the rear shocks before long. And maybe replacing the air bags with heavier steel springs.

 

[buckland]

Squatch. That is exactly what happened to me in PA on the same road... It never happened since. That cement was worn onto camel humps and the porpoising just amplified.... Only way I could drive was to get off the Highway and go back roads! I wrote to the Highway dept and the Gov. Won't go back through PA until the roads are new.

 

[takesiteasy]

I-80 in Nevada does this to my truck also, along with ruts in the pavement from tire studs. I won't drive that road again.

I don't have air bags but I've had the porpoising experience a few times- not often enough to do anything to the truck yet. It is irritating when it does happen.

 

[WAhawk]

For what it's worth, we have a Ford F150 + Hawk + airbags that had a bucking problem on the highway. It took six years but we finally figured it. The problem was caused by condensation around the spark plugs that caused misfiring. The moisture finally got bad enough for us to figure out the correct plug to change. (We live in western Washington). Problem solved.

 

[shellback]

I know all about I-81 in PA. It's terrible, and guess what? We have the highest gas taxes in the US! An old joke, A Penndot foreman called in one morning to report all their shovels were stolen. He asked what should he do. The supt said just lean on each other till they can get some more shovels out to the job!

 

[Squatch]

Just got back from yet another almost 2,000 mile trip. My Tundra has the stock shocks on it. It is becoming obvious that they are getting tired now that I'm running the camper a lot. So this winter It'll be getting new shocks. I'm also looking into adding some heavier rear springs.

Other than that the above mentioned I-81 deal was the only issue we've had!

 

[john cotterman]

Just got back from yet another almost 2,000 mile trip. My Tundra has the stock shocks on it. It is becoming obvious that they are getting tired now that I'm running the camper a lot. So this winter It'll be getting new shocks. I'm also looking into adding some heavier rear springs.

Other than that the above mentioned I-81 deal was the only issue we've had!

All four shocks to be replaced? Just rear, just front? What's the reasoning for this choice?

 

[PackRat]

Hmmm...sounds like reports from some owners point to the composition of the highway (concrete) and the amount of damage it has sustained. Furthermore, most report that the condition exists either for a small percentage of their total miles driven or to certain highways. In addition, it seems that changing ones' speed can make a difference to the bounding effect.

So...one has several options here:
​1) get out of the lane trucks have destroyed (if that is possible)
2) get off that highway and choose an alternate route
3) find a speed that either minimizes the effect or eliminates it if #1 and #2 are not possible
4) throw thousands of dollars at a "problem" your truck does not have....the bouncing is the symptom, the highway design/condition is the problem.

Trying to mess with the suspension for a problem that occurs in pretty much easily identified highway routes and speeds seems to be a waste of money unless the suspension of your truck is not set up for the camper you have in it anyway or it is worn out.

It would seem to me that to smooth out the bouncing you are only "softening" the suspension so the ride is less rough.

Sounds a lot like why passenger aircraft choose to fly at a different altitude when turbulence is causing a bouncing/rough ride....they don't redesign the aircraft, they just find "cleaner air" with less turbulence and change altitude!

Just $0.02 cents worth of speculation here....

 

[buckland]

ditto. Road surface ... segmented cement.... builds harmonics then it escalates. I had to keep two wheels in the breakdown lane to get off that highway. They are tearing all of them up but it will take years.

 

[iowahiker]

We have driven that section of I-81 without trouble in the truck lane (right) routinely. Our longer wheel base plus OEM heavy duty shocks and springs at all four corners works well. The payload package was the best money we ever spent, $1500 for heavy duty shocks, springs, and E rated tires at all four corners plus the larger rear axle (nothing like steel).

 

[john cotterman]

PackRat,

I was on (otherwise) good concrete Interstates this summer in Wyoming, Nebraska, and Missouri. The only thing in common with my porpoising events was the grooving in concrete surfaces. It was really bad between 60 and 75 mph, not leaving much speed range to drive in. We got off the Hwy more than once just to avoid it. I know the PA hwys but this is another problem.

 

[Redfish]

I posted earlier in this thread (#2 and #29) about major porpoising issues with my 2016 Tacoma/Fleet combo. In total, I've now driven my truck/camper about 24,000 miles. After doing some research and reading about other folk's experience on this site, I had adjustable Rancho shocks and struts installed this summer while out West. I already had Firestone airbags and E-rated tires. The Ranchos replaced stock front struts and Bilstein 5100 rear shocks. I've now driven approximately 6,000 miles on this new combo, including everything from very rocky, potholed and/or washboarded FS/BLM roads to every variation of bad to good segmented concrete high speed highways and paved roads. The final porpoising test was driving from MT to FL last month, which included hundreds of miles of segmented concrete roads. By playing around with the shock/strut adjustments, the Ranchos have almost completely eliminated my porpoising problem, plus they give me much greater road feel and handling on washboard dirt roads. The camper is now off my truck and I've readjusted the shocks/struts back to something approaching the original stock ride. Note that I also had to install a sway bar relocation bracket to eliminate rubbing between front strut and sway bar, but this was a simple and cheap fix. Thanks for sharing your insights and I hope my experience helps someone else.

 

[Squatch]

All four shocks to be replaced? Just rear, just front? What's the reasoning for this choice?


I'll replace them all. I believe in matching all 4 corners. My main reasoning is that the stock shocks on all vehicles are pretty wimpy. At 60k miles mine are showing they are tired. Time for better shocks that will last some time. I intend to have this truck a long while.


I'm thinking these. Maybe crank them up an inch or so up front.

https://bilsteinlifts.com/shop/toyota-tundra/00-06-toyota-tundra/bilstein-6112-0-2-front-5160-0-2-rear-lift-shocks-00-06-toyota-tundra-4wd/

In my case this is not to stop the occasional bucking issue. it's just a matter of getting my truck where I want it for my type of useage.

For rear springs I may contact Deaver or Alcan spring or maybe just get a set of these.
http://4x4.fatbobsgarage.com/toyota-tundra-5-leaf-heavy-duty-rear-spring-single-4wd2wd-2000-2006-p8519.aspx

 

[Redfish]

I agree with Squatch -- replace both front and rears with matching shocks and struts. Part of my original problem was do doubt only replacing rear shocks, which helped with carrying the camper on rough and washboard roads, but no doubt exacerbated the bucking issue -- a rookie mistake. I choose not to mess with springs because my camper is only on my truck 50% of the year.

 

[PackRat]

I believe this problem is not only due to the wave-wear that semis do to the road surface, but possibly the combination of your speed and wheelbase and the distance between the expansion joints in the concrete road surface. Has anyone who had this problem on roads such as this experienced the same bounding effect when on an asphalt surfaced road at the same speed? When I was a kid, we travelled Highway 99 in the summer and it rode and felt like that due to the shortness of the concrete sections and the expansion joints crumbling under 80,000 lb. semis. The "fast lane" wasn't much better, but once off that road the problem went away....and this was in the family station wagon!

If of course, the suspension of your truck is lacking with the load/speeds you drive at then the problem would be worse on "bad" roads. My question is if it is necessary to go beyond the suspension upgrades an already maxed out truck has is worth the cost to fly down the highways when so little of those highway conditions exist and your time on them will be minimal.

I believe anytime you redesign the shock/spring/air-bag suspension on a vehicle it will end up either "riding like a truck" or "riding like Grandma's Buick" especially when on different surfaced highways and especially with the camper dismounted.

But....if you experience this problem all the time and at any speed over 55 then you already have suspension issues that need addressing! Comparing apples to oranges....different trucks, different campers, different road surfaces, different speeds, different suspension set-ups....all that can contribute to a "hard", "mushy", "bouncing effect" or an uneven set of the truck/camper once mounted in the truck bed.

Your results may vary....so don't just copy the other guy's rig without determining if you BOTH have "apples or oranges" so to speak!

Starting with a truck that can haul your camper and everything/everybody who will hit the road is the first order of business...trying to make the truck handle the camper and stuff is the wrong way to go but that's just my opinion...

Do your homework on what you want to carry...THEN find a truck that can handle it or you will be spending plenty of ca$h trying to "upgrade" the truck/suspension to handle it if you started off with a truck that wasn't cut out for your load.

Never send a boy to do a man's job....so they say.

Adding better shocks when yours die is one thing....having to add springs, air-bags, etc. right from the git-go indicates to me you bought "not enough truck" to begin with.

 

[shellback]

My 2016 Chevy Z71 also bucks on I-81 when towing my boat, no camper onboard. Packrat is right on, but bad suspension can be another problem. I-81 is terrible up in the Scranton area of PA. Rt 322 west of Harrisburg, PA used to be bad also. They overlaid the concrete with asphalt and no more bouncy bounce.

 

[ntsqd]

All roads cause the suspension to move. That's it's job, to comply with the terrain which the vehicle is driven over with minimum upset to the occupants. To say that some particular highway section is at fault is incorrect, and to then say that the suspension shouldn't be adjusted to deal with it is faulty logic. It may not be worth pursuing if you've only ever driven that section once and will never do so again, but that section revealed a fault in the tuning of the suspension that may or may not show up somewhere else.

If you are getting harmonics then the dampers aren't dealing with the inputs as they should be. It is that simple. It is not the road's fault, it is the suspension's fault. Some oscillations just aren't going to be tuned out without spending a lot of time and money to do so. Others are simple to tune out and they should be.

 

[shellback]

All roads cause the suspension to move. That's it's job, to comply with the terrain which the vehicle is driven over with minimum upset to the occupants. To say that some particular highway section is at fault is incorrect, and to then say that the suspension shouldn't be adjusted to deal with it is faulty logic. It may not be worth pursuing if you've only ever driven that section once and will never do so again, but that section revealed a fault in the tuning of the suspension that may or may not show up somewhere else.

If you are getting harmonics then the dampers aren't dealing with the inputs as they should be. It is that simple. It is not the road's fault, it is the suspension's fault. Some oscillations just aren't going to be tuned out without spending a lot of time and money to do so. Others are simple to tune out and they should be.

Not sure if you have much experience on concrete roadways in northern freezing climates. Heavy truck traffic and frost does heave the roads and causes the bucking. It's a common scene in the northeast to see concrete roadways being repaired due to heaving at the joints. I run I-81 from PA all the way north till it ends at the Canadian border. Each year they are always working on new sections to be repaired. They also run machines which I believe are called profilers. They follow the contour of the road and use a diamond grinder to level the humps. I think some roads are worse than others due to the spacing on the expansion joints.

 

[ntsqd]

I've driven on those NE roads, but not a lot. We've got a stretch of exactly that kind of heaved concrete pavement right here in town, though I highly doubt that it got that way from freezing - not on the lower-left coast. The right wheel base, say a GM extended cab long bed truck or an 80" WB dune buggy, and the right speed, say at the speed limit of 45 mph and you're bucking around like one of the ponys in front of the drug store.

We made the Chevy work well on that stretch of pavement, but it really needed a stiffer frame. The buggy was sold before the knowledge needed to make it work was known.

I've also driven on Mexican wash-board, the likes of which only two roads in the US come close to, Saline Valley Rd & the road to the Racetrack from Ubehebe Crater. Hole in the Rock and Cottonwood Cyn wash-board are notable, but not in the same class. All of these roads can be driven in comfort if the dampers are set-up correctly. Rancho RS9k's may start out doing OK on wash-board, but unless you are going slow (4 vs. 40) they soon fade and become worthless. BT, DT. Our current 4rnnr Tow'd came to me with RS5k's under it. The rears are nearly dead. One trip to Carrizo Plain did them in.

 

[Squatch]

I've had RS5000's on a couple of trucks. Total junk. Too much compression damping and not enough rebound. Pretty much turned me off to Rancho a long time ago.