66 replies to this topic

[WxMan]

Has anyone experienced a serious bucking/bouncing/shuddering problem with their Fleet FWC on a 2011 Toyota Tacoma 6-ft bed.  The problem I’m having is bucking (some call it shuddering) at various speeds, most noticeable between 30 and 40 mph but worse on segmented concrete pavement (porpoising would be the best way to describe the ride on concrete roadways). The current configuration includes an OME suspension upgrade kit (front coil springs, Ntrocharger front Sport Struts and Shocks,  back leaf springs SPC adjustable upper control arms and Timbrens).  More importantly has anyone resolved these issues to their satisfaction.  The problem is driving me a little crazy having invested in the suspension upgrade kit but the problem with bucking/bouncing still persists.  Any recommendation would be appreciated. 

[Redfish]

Many thanks for raising this problem. Yes, I've had similar issues. I'm driving a 2016 SR5 4x4 Tacoma carrying a 2016 Fleet with a delivered weight of 1300 lbs. I carry minimal and only very lightweight gear so far (i.e., think lightweight backpacking gear and a few flyrods) and my wife and I are not big people. However, i don't know my loaded axle weights or overall weight.

 

In preparation for carrying my camper, I installed Firestone air bags, Bilstien rear shocks, and E-rated tires. My empty truck was almost undriveable on some segmented concrete freeways and highways on the 2,200 mile trip from Florida to Arizona to pick up my camper last spring.

 

It drives much better loaded, but I still encounter dangerous harmonic front to back bucking on some particularly uneven segmented high speed concrete roads. I've tried different speeds and air pressures in my tires and air bags, but while much better on normal segmented roads, the problem still persists on bad sections. Driving at slower speeds and reducing the air pressure in the air bags helps. I typically drive 55-60 miles per hour on highways/freeways. I go out of my way to avoid interstate freeways and some state highways by preference, but sometimes it's unavoidable. I put 12,000 miles on my camper/pickup last summer and haven't experienced any other handling issues except for this problem (e.g., it corners fine, handles 40+ mph sidewinds and passing trucks with ease, etc.).

 

The on-line research I've done suggests that installing adjustable rear shocks might be the answer (e.g., Boss). My camper is mounted only part time and I use the truck for hauling other stuff. I'll be very curious as to what other's recommend.

[Redfish]

And my problem occurs at higher speeds--50-65 mph, not at lower speeds mentioned by the OP.

[Stalking Light]

When I first had my Eagle on my Tacoma it would porpoise on the highway. At the time I had just added airbags and E rated tires. I ended up with an OME lift with heavy springs front and read and an extra leaf in the rear. I also have added an ARB front bumper/winch and an Aluminess rear bumper. No porpoising now but I can't say exactly what change fixed the issue for me.

[nikonron]

Try letting some air out of the airbags to let the suspension work. Worth a shot.  Ron

[RC Pilot Jim]

I have had the same problem with our 2012 4 x4 Tacoma an Eagle. The first time was on the Oregon coast highway south of Florence.
Porpoising so bad at 50 mph I thought the rear tires were coming off the ground.! Slowing down to 45 stopped it. Only on concrete not asphalt.And to some degree I have experienced it on Calif highways.

A road engineer said condition caused by heavy trucks that compress the surface between the expansion joints and the wheelbase of the Tacoma......and certain road speed. Slow down and condition lessons.

He didn't have any other solution.

Edited by RC Pilot Jim, 01 January 2017 - 12:41 AM.

[FreezingMan]

I have a 2014 Tacoma crew cab, code e Goodyear duratrac tires, bilstein 501 shocks all around, and ride rite airbags. Tire pressure is 35 psi. Air bag pressure is 30 psi. I haven't experienced what you have so I can't offer any more help than what I run at. When I first got my Fleet I spent some time figuring out the tire pressure and airbag pressure to get a smooth ride.


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[buckland]

I am not positive what exactly the dynamics are that cause this but it happened to me on my Eagle/Colorado combo but I got it to go away by working out a similar set up as Freezingman. It takes time to adjust the airbags as there is a specific pressure at which the porpoising goes away...based on your camper/gear weight, tire type and pressure, and road condition (I might add how one distributes the gear inside also figures in). But I have found that there is a "Sweet spot" for the airbags ... too little or to much ...combined with the other variables makes it prone to bucking.... though cement segmented roads are an abomination... ever been in Pennsylvania?

Try first airing down the bags...then going up in 5 lb increments...starting at say 15 or 20. It actually worked for me.

Porpoising can also be decreased when it starts on those cement roads by quickly varying speed ...a pain but alternating gas and coast gets one through the crazy stuff. ( Gawd! I hate when that happens!)

[Advmoto18]

Regardless of truck, the fewer and fatter your rear leaf springs/pack, the harsher (tooth jarring) the ride.  One of the great things about the OME leaf spring design is the use of more leaves of thinner design.  

 

When I was contemplating purchasing/installing an OME lift kit on my old truck, I called the OME owner down in AU.  He told me he designs the spring packs so he could blast around the Outback and not spill his coffee.  IMO, he succeeded.  I will install a 3" OME on my new truck this summer.

 

I also installed the OME overload leaf spring in the pack since I leave my camper on the truck all the time.

Edited by Advmoto18, 01 January 2017 - 02:40 PM.

[nikonron]

I also have the OME leaf pack with the overload leaf, rides and handles fine on my Tacoma with Eagle.  Also have the OME Nitrocharger shocks on the rear.  Ron