Excessive side to side movement with camper box

[EsbenDenmark]

I have rebuild my hzj75 series with a camper box.
So it is is not only heavy but TOP heavy too.

I have installed Terrain Tamer parabolic leaf springs and Terrain Tamer TGS expanded body shocks.
I also installed a rear sway bar from the 79 series.

Now that we are travelling I am experiencing a lot of fast side to side movement when doing offroad and dirt roads.

I feels like the rebound is way to fast. (I am guessing a bit here as I am not an expert)
Dont want to tip the truck.. that would suck!

Maybe the TGS shocks just is not up for the task? Especially with the parabolic leads that has very little resistance compared to normal leaf springs.

Does anyone have experience with the Terrain Tamer PRO shocks? Or other brands / models with adjustable compression and rebound?

 

[locklaw]

You'll need to clarify what side to side movement you are getting. Sway, wiggling arse or bouncy?

Parabolics, given their design, offer less side to side stability compared to a traditional leaf pack. You just don't get around that.

The rear 79 series sway bar, is it a factory/OEM retrofit piece or an aftermarket HD unit?

BP51's from Old Man Emu/ARB offer individual compression and rebound settings capable of handling and taming bigger camper setups than yours on a 70 series, but other items need to be correct too.

 

[EsbenDenmark]

I would say a bouncing sway..
You know when on wheel hit a hole and The suspension compress, come back up, and then the wheel in the other side hit a hole...
Have to drive really really really slow not to have it get worse and worse..

The 79 Series rear sway bar is a heavy duty Old Man Emu.

Ok.. that is what I understod also.. less friction in the parabolic leafs.

 

[locklaw]

Ok, that seems to be a rebound issue. Specially, the shocks cannot dampen the rebound action of the weight and with the Emu STAB09 sway bar, thus the bouncy ride. Convince a local 4x4 shop to fit some BP's, set compression to 6 and rebound to 8, maybe 9 if you are loaded, the test it out.

I would say a bouncing sway..
You know when on wheel hit a hole and The suspension compress, come back up, and then the wheel in the other side hit a hole...
Have to drive really really really slow not to have it get worse and worse..

The 79 Series rear sway bar is a heavy duty Old Man Emu.

Ok.. that is what I understod also.. less friction in the parabolic leafs.

 

[Lo2aY]

You need a heavy load swaybar and probably harder shocks if your springs are the correct spring rate for the load.

 

[renago]

I would start in adjusting the shocks .
It is a slow process, and it takes time and patience.
Start with registring on paper the compression and rebound settings .
Make just 1 change at a time , and test the truck drive .
harden the rebound at increments of 5 clicks .
Considering the heavy weight also + on the compression will help .
Every time you change settings , register on the sheet what you do . So you can go back to the starting point .
Of course you need to test the truck on a bumpy road that you think is right for the task .
Test drive should be done on the same road at same speed , same vehicle weight .
This will allow also inexpert drivers to “feel” the different settings that you do .
Be prepared Setting will take you easily 1 full day !!!

 

[EsbenDenmark]

You need a heavy load swaybar and probably harder shocks if your springs are the correct spring rate for the load.

Already have a heavy duty rear sway bar.. the front is the original.. not sure if I can get a heavy duty for the front for a 75 series

 

[EsbenDenmark]

I would start in adjusting the shocks .
It is a slow process, and it takes time and patience.
Start with registring on paper the compression and rebound settings .
Make just 1 change at a time , and test the truck drive .
harden the rebound at increments of 5 clicks .
Considering the heavy weight also + on the compression will help .
Every time you change settings , register on the sheet what you do . So you can go back to the starting point .
Of course you need to test the truck on a bumpy road that you think is right for the task .
Test drive should be done on the same road at same speed , same vehicle weight .
This will allow also inexpert drivers to “feel” the different settings that you do .
Be prepared Setting will take you easily 1 full day !!!

Hi.
Yes totally agree BUT there is no options for adjustment on the shocks I have on..

I am seriously considering getting a set of new shocks and see if it can help.

 

[Rigster]

Hi.
Yes totally agree BUT there is no options for adjustment on the shocks I have on..

I am seriously considering getting a set of new shocks and see if it can help.

I am going to guess it is too late to take the other ones back and exchange them, but perhaps you can sell them to someone else local and recoup some of your costs to put towards the more expensive adjustable shocks.

No one likes to be on the edge of their seat, especially on some not so terrible trails - it's exhausting... then to get where you are going and having to reorganize the stuff in the camper, sheesh. Best of luck getting this sorted!

 

[EsbenDenmark]

Tried getting a couple of videos today.. not sure how well it shows the movement.

land Cruiser movement 1

youtu.be

land Cruiser movement 1 - https://youtu.be/q3aIZD-RAII?feature=shared

 

[Rigster]

Tried getting a couple of videos today.. not sure how well it shows the movement.

land Cruiser movement 1

youtu.be

land Cruiser movement 1 - https://youtu.be/q3aIZD-RAII?feature=shared

I think the rolling/swaying in the videos is pretty normal for having a camper on. I had another thought - do you still have the old spring packs? I realize this is a lot of work, but I also know that sometimes it is worth the effort to dial things in. You could try installing the regular OEM spring packs in the rear to see if that helps significantly enough to leave them in. It looks to me like the camper install is a permanent install? If so, then the parabolic springs may not be the best for a static load like that.

The one final thought I had was adding airbags in the rear, they are adjustable (from within the cab with a gauge if you add that expense in too). This is again throwing money at it, but it IS another option. The cheapest would be to put the old springs back in the rear to start with and test.

 

[Lo2aY]

Already have a heavy duty rear sway bar.. the front is the original.. not sure if I can get a heavy duty for the front for a 75 series

what spring rate are you running in the rear?

 

[EsbenDenmark]

The campe

I think the rolling/swaying in the videos is pretty normal for having a camper on. I had another thought - do you still have the old spring packs? I realize this is a lot of work, but I also know that sometimes it is worth the effort to dial things in. You could try installing the regular OEM spring packs in the rear to see if that helps significantly enough to leave them in. It looks to me like the camper install is a permanent install? If so, then the parabolic springs may not be the best for a static load like that.

The one final thought I had was adding airbags in the rear, they are adjustable (from within the cab with a gauge if you add that expense in too). This is again throwing money at it, but it IS another option. The cheapest would be to put the old springs back in the rear to start with and test.

The camper is actually a demountable so we can take it off and explore with just the truck.

Already have a set of airbagman helper springs in the rear. Those do help but only limit the sway a little and not the fast side to side movement.

Maybe since there is not really any friction in the parabolic leafs....

 

[EsbenDenmark]

what spring rate are you running in the rear?

 

[renago]

500 kg springs are far to low !
Try to weight THE truck .THE gross weight will give you a true indication on what springs you need.
Air cushions only lift THE truck . They do not act as a spring, or just very marginaly
If you have standard shocks not adjustable , THE job will be difficult.

 

[Lo2aY]

You need to weigh the truck before we can start pointing fingers at parts. You might be undersprung for the load. So before you start throwing money at it. Run a quick weight test per corner fully loaded and give us some figures.

If you are undersprung, then there is a chance that the shocks are working overtime trying to stabilize the loads above. Also double check the air in your airbags, if you have leaks overnight, it won't be doing much if they hold little pressure.

 

[JuanJ]

Hello,

Apparently, your shock absorbers are working overtime.

The shock absorbers/sway bar combo should stabilize your rear. If one of them is not working properly, the leaf springs will see additional stress, something that may cause imbalances and, eventually, leaf spring failure.

You may want to check the shock absorbers that can be used with your parabolic leaf springs, aside from the ones you have.





Juan

 

[EsbenDenmark]

You need to weigh the truck before we can start pointing fingers at parts. You might be undersprung for the load. So before you start throwing money at it. Run a quick weight test per corner fully loaded and give us some figures.

If you are undersprung, then there is a chance that the shocks are working overtime trying to stabilize the loads above. Also double check the air in your airbags, if you have leaks overnight, it won't be doing much if they hold little pressure.

Not precise measures
(Measures with Reich weight)

Left front 700

Right front 680

Right rear 1100

Left rear 1040

Total 3540

 

[Lo2aY]

Not precise measures
(Measures with Reich weight)

Left front 700

Right front 680

Right rear 1100

Left rear 1040

Total 3540

Ok you have 2240kgs in the rear. So the springs need to be replaced for a heavier weight. So you need a much heavier weight spring.

OME goes up to 600 kg per spring so you are still going to be under sprung.

I highly recommend shifting as much weight down as possible. In the video, the car is shifting not just because of the weight but also because of where the weight is located. Try to move and pack things as low as possible.

Remove unnecessary items. There are things that you may not need or have not used in a long time. Remove it and keep the weight low.

I lower weight vehicle will make it handle better, save fuel, offer more range and more importantly have less wear and tear to the car.

If you can't remove weight, see if you can use 79 series rear 800 kg springs along with the airbags. That might be the solution if you can't remove weight.

Good luck

 

[renago]

Your empty truck is rate 2300 kg , fully loaded 3500, you are 1200 kg of extra weight !
You have to work on this data .
Even more considering the height of the weight .
Parabolic Leaf springs are nice but not Fit for this Kind of job and load .
I would go back to good old tradizionale leaf springs . You can tune they to your needs, adding or eliminating 1 leaf at a time .
Not expencive , and serviceable any were in the world.
If possibile would invest in a good shock kit , with adjustable settings.
I have been in your situation many years ago
Just my 2 cents