vx100 suspension upgrade leaving ahc in tact

[vx100]

Hi there, has anyone upgraded the suspension on the VX 100, leaving the AHC in tact?

My load is now 300kg over the handbook 525kg, and now the AHC can not cope. Can I trick it maybe by simply turning up the torsion bars on the front a touch, and replacing the rear coils with some more stiffer, not longer?

 

[MoGas]

Welcome to the ExPo.

For a query like this, you will probably get more assistance in the 100 Series technical section of IH8MUD.

Dave

 

[MoGas]

Also, Maybe Christo Slee will weigh in on this.

 

[hoser]

Hi there, has anyone upgraded the suspension on the VX 100, leaving the AHC in tact?

My load is now 300kg over the handbook 525kg, and now the AHC can not cope. Can I trick it maybe by simply turning up the torsion bars on the front a touch, and replacing the rear coils with some more stiffer, not longer?

Replace the torsion bars and the rear coils with the NON-AHC Land Cruiser 100 t-bars and coils and your load capacity will go up considerably. Cranking up the T-bar and using some small spring spacers in the rear will help but it sounds like you need more than that if you are 300kg's over.

With the 100 series rear coils, you may have end up with more lift in the rear than you want. You can also try the standard OEM Land Cruiser 80 series springs in the rear which are a little bit softer and should ride lower. But be aware, the 80 series coils are uneven length. So you'll need either two of the shorter side coils or two of the longer side coils (or like a 12mm spacer on one side).

You could also add airbags to the rear or replace the rear springs with airbags.

 

[sleeoffroad]

Hoser, pretty much has it. You need more spring capacity, not just height. However if you put to much spring in, the truck is going to take all the dampening out of the shocks due to the height readings it gets from the sensors. So what you want is to get the truck to sit at the same height, but get springs with more rate.

 

[hoser]

Yup, if you do go with different springs, you are going to have to play with the rear AHC sensor so that the shock damping is correct. And then adjust the front sensors accordingly being certain you have enough suspension down travel and proper rake.

It's kinda tricky and a brake pressure gauge would be helpful to measure AHC pressure. But you could also just trial and error adjust it.

 

[vx100]

Thank you Hoser, Slee and Mogas for your valued advice.

I am not sure where to get the specs of the existing rear springs from, but I located some specs of springs which appear to be an inexpensive start.

Free height is 490 mm, bar diameter is 21 mm and spring rate is 63.1 N per mm. Not sure what the OD is though, but will try and match them to the existing OD. Also I am not sure what the exact compilation of the material is that will be used to make the spring.

A local spring manufacturer can make these up for me, and can have them heat treated and scragged, but not shot peened.

In terms of adjusting the AHC arms at the rear and front, is there any technical information available that you know of.

 

[hoser]

Here's some info on the stock AHC pressure value.

And here is some info on replacing the springs with airbags. I know people have mixed feelings about airbags but thought I'd throw it out there.

 

[vx100]

Thank you Hoser, both lots of information is really great and informative. Will eventualy post what mods I settled on to alleviate the problem of overweight. Then the trip through Africa will be the proof - one way or another.