Interstingly while MB makes the off-road package standard on the 320 CDI pretty much everywhere else in world except the USA- I have an interesting question:

The off-road package gives approx 1" additional ground clearance over the standard airmatic. I am guessing that the suspension components are identical between the CDI with and without the off-road package, so does anyone know if it is possible to "reprogram" or modify the software to give you that extra 1" of lift on a USA 320?? The locking Differentials are probably overkill for this type of vehicle and it's intended use, but an extra inch of clearance would be nice to avoid any dents in the truck.

Any ideas???

-Chris

 

Welcome to the forum, Chris. Glad to see that you are keeping the quest alive after many others have fallen on the wayside.

 

Well, one change, I got a 320 CDI, and it is great!!

For the suspension- One easy fix would appear to be to "trick" the airmatic. Just as the lowering kits available change the input by altering the length of the control arm the goes to airmaitc sensor, thereby lowering the vehicle. You should easily be able to do the oppisite and fool the computer that the truck is actually ~1" lower than it should be... This would give an easy 1" lift, and assuming the airmatic components are the same on the off-road and non-off-road models, the lift button should give a lifted height which is the same as the off-road package.. It is interesting to be trying to do the oppisite of the current popular trends...
i am going to call the company that makes the adjustable links and see if the specs of their product sould allow such an activity..

 

Did you manage to find a solution for this yet? Were intertested myself in accomplishing a lift

 

I called the Guy in Canada at www.adjustableairride.com He makes a kit for lowering the truck, with adjustable links. It basically "tricks" the air-ride computer into thinking that the truck is too high, and therefore it lowers the vehicle. Obviuosly if you can go down, you can go up....

I talked with him, and not suprisingly no one has asked to go higher yet, but he made me a custom set of links, that will allow me to set the ride higher at baseline.. I have the links, but have not had the time to install and play with them yet.
This solution will work. Everything that I have found says that the suspension components are identical between the off-road package and non off-road package trucks, the extra lift comes from the software. So, by setting the ride 1" higher at baseline, by pushing the button it will still go up 3", for a total of 4" of lift. (this is slighly less than the about 4.2" that the off-road package gives, so there is a little margin left). It is also very easy to return it to stock by simply re-installing the factory links.

The downsides-
1) no true adjustablilty like the rotary switch (i.e. 1", 3", 4.2") it is either 1" above at baseline or at 4" with the button.
2) you loose the safety mechanism by which the truck lowers down from 4" at speeds above 25mph. I am not worried about this as the center of gravity of the truck with 4" of lift is still way lower than may other trucks I have owned, and I won't be needing the extra 3" unless gowing slowly anyways, but it is something that should be kept in mind
3) the extra 1" of lift at baseline will obviously slighly lower mpg at highway speed, due to increased drag, but it will be a small amount


Tires-
I have installed a set of Yokohama Geoland A/T's size 265/70/R18- These are 32.7" tires, and they fit PERFECTLY, no rubbing. They are just over 2" taller than the stock 265/60/R18's (32.7 vs 30.5) So there is an extra inch of ground clearance just from the tires. They are aobut 7% bigger than the stock tires, with unbelieveably better off-road ability
I just went on a long trip, and these tires are GREAT. Even with the extra 1" of height from the tires, there was only a 0.3 mpg differene between
the factory tires and the Yokohamas as measured by the computer. This is VERY interesting, because with a 7% bigger tire, you are actually going 7% further in true distance that the computer thinks, so the real mpg difference is likely almost non-existant. Not too suprising given the tourqe of the motor, and similar rolling resistance of the tires.
Just with the larger tires the effective lift of the truck is now 4" without tinkering with the airlift, and it does much to imporve the approach and departure angles for mild off-roading

Note- I am not trying to turn this truck into a rock-crawling machine, it is not desinged for this, and is WAY too expensive to bash into things. This is why I have no strong deisre to to add lockers to it, especially with the ESP. From this weekend I can tell you that it does suprisingly well off-road, especially with better tires. But the ability to have excellent on-road perfomance, and with the push of a button, to have a capable off-road vehicle is wonderful. And the extra clearance from bigger tires and extra lift will help protect the body from hard and unmoveable obstacles

I will post some pictures when all is done...

 

I wonder whether the '09s will have this option for the US market. I would think that for current models, a rewrite of the software would be the best way to go. If there isn't allot of call for this feature, it might be hard to find someone who is writing software revisions.

Perhaps the dealer can get ahold of the European software version for people wanting the off road adjustability??

 

There is guy in southern california who lifted his GL to fit 35 tires. basically, it involves adding spacer and modify linkages. Here is what he wrote to me about the inquiry I had.

"That GL450 was running 35" tires and we only installed a 2" spacer in the front strut to level it out and the put it in off-road mode which up it up 5".
To do it correctly you would need to make all new ride adjustment bars with spacers and it will ride like stock but lifted!

Randy
Rod Benders Customs
San Juan Cap. Calif.
karguy61@yahoo.com
(949) 677-1191"

Talk to him see if it would work for you.

 

Chris I have a 2009 gl blue tec and want to put some off road tires on it. Do you know if 18 " rims would fit that truck? How did yours turn out?

 

Did you ever get pictures on this? I'd like to do the same when it's time to change tires to fit a nice all terrain.

 

there must be a mechanical difference as a part of a troubleshooting effort i had a truck sit very high (about an inch and a half over the raised position) and there was severe binding in the rear- going over bumps produced very loud clunk and i could feel the suspension having zero give. shortly after that one of the rear bags blew up (literally).

so... just an observation.

 

One more thing to note, since I recently exploded an airbag. When the bag deflated, the truck came to rest on the bumpstop. I'm not sure how much clearance there was. With new links, you raised the vehicle 1", but you increased the tire size by 2". I'd be curious to know, in the rare circumstance of an airbag blowout like I had, if you'd be rubbing the wheel well with a 265/70/r18 tire vs playing it safe with just a 265/65/r18 tire.

To me, the 265/65/r18 tire would be the safer bet in case of an airbag collapse, but you'd have to test it to be sure.