Airbags to help rear suspension on a 416 Unimog??? Any suggestions?

[87GMCJimmy]

It's not a camper but, it is an offroader-

We have a 416 (maybe 406? I am not 100% confident in my Unimog identification skills) Unimog that we built a custom rear cage setup for, to be able to carry 16 passengers. It is for a customer, they have a church camp and they have the Unimog set up to give the kids the experience of offroading.

The issue we have encountered is that although it has the heavy duty rear spring package, it still feels too soft in the rear when loaded. The customer says that now with all the extra weight in the rear (and inherently higher COG) it feels like it sways too much and feels tippy.

Are there heavier duty rear springs readily available?

Or (perhaps the better approach), what could we do in the way of a rear airbag setup? One that would retain flexibility but would add load carrying capacity and stability when loaded.

Here is a pic of the rig:

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Any help would be greatly appreciated! Thank you!!!

 

[mogwildRW1]

It's not a camper but, it is an offroader-

We have a 416 (maybe 406? I am not 100% confident in my Unimog identification skills) Unimog that we built a custom rear cage setup for, to be able to carry 16 passengers. It is for a customer, they have a church camp and they have the Unimog set up to give the kids the experience of offroading.

The issue we have encountered is that although it has the heavy duty rear spring package, it still feels too soft in the rear when loaded. The customer says that now with all the extra weight in the rear (and inherently higher COG) it feels like it sways too much and feels tippy.

Are there heavier duty rear springs readily available?

Or (perhaps the better approach), what could we do in the way of a rear airbag setup? One that would retain flexibility but would add load carrying capacity and stability when loaded.

Any help would be greatly appreciated! Thank you!!!

That is a 416.

Does it have the helper springs in the rear? They are little coils inside the regular coils. What about swaybars? The stock coil springs on a Unimog are progressive, so as they are loaded down, the spring rate changes (if that's the proper way to explain it)

More weight in a Unimog may perceive as more "sway". The Unimog frame is designed to twist and articulate. When you see pictures of Unimogs on the test track, they are usually weighed down for that reason, to make the frame twist and keep all 4 wheels on the ground during extreme offroading (and also to keep the back end on the ground since most of the weight of an unloaded Unimog is up front). That is also why everything attached to the frame is 3pt mounted.

I don't think you need extra load carrying capacity, the manual I have states the Curb weight is around 3600kg's (7920lbs), the GVW is 6000kg's (13,200lbs), even if those 16 church kids are ginourmous, depending what the added cage weigh's, you should still have a bit of room.

I don't know squat about roll cages but that truck stock weights in around 8000lbs, and I've seen rolled ones mutilate the stock cab with ease. What is the roll cage tied into? (I'm not saying it's not up to snuff, just wondering how it's tied into the floor and want you to be aware of the vehicle weight if you weren't already)

Here's an example of a Unimog with a rear cage to show how stable they are:

www.youtube.com/watch?v=QxnDDxWR_Rw

One option is the rear springs may be worn out? It is a 25+ year old tractor You might find rear springs from a Unimog (Freightliner) 419 SEE with rear excavator are stiffer, I'm not sure though.

 

[grizzlyj]

More weight in a Unimog may perceive as more "sway". The Unimog frame is designed to twist and articulate. When you see pictures of Unimogs on the test track, they are usually weighed down for that reason, to make the frame twist and keep all 4 wheels on the ground during extreme offroading (and also to keep the back end on the ground since most of the weight of an unloaded Unimog is up front). That is also why everything attached to the frame is 3pt mounted..

This.

There are so many areas flexing it does feel and look a bit weird. I'm told some camper conversions (not mine) have fitted dampers to slow down the sway, but I've also heard that they either need to be massive (because they're trying to stop what the truck was designed to do) or they break.

Relax and enjoy the ride may be the best advice?

 

[fietsryer]

If it were me, I'd address the issue in the following sequence:

1 - as suggeste by mogwild, check if you have the helper springs installed. If not, get them and see if this solves the issue

2 - if 1 doesn't address the problem, as suggested by mogwild, check if you have a sway bar installed. If not, install one.

The above should imho adress your issues while keeping the mog standard.

If that doesn't help, airbags is an option. I know of two 416 campers who has done this with success. They replaced the small helper springs with inflatable airbags. The downside of this is you loose most of your articulation...