Hi John. I appreciate your comments here and am in full agreement about the weaknesses of this suspension system. (For background I’ve been an automotive test engineer for about 20 years and also do my own suspension work and tuning/valving on my off road powersports vehicles.)

I know many of the die hard Mercedes fans don’t like to hear it, but you are right about this suspension, it’s weak and has limited travel, but also very poor geometry which would prevent good performance even if travel is increased.

I’ve considered building a longer travel independent suspension for my ML, incorporating better geometry to maintain better tire control across the whole range of travel. Of course that’d require different upper control arm mounting points for sure, and custom knuckles to reposition the ball joints and move them outboard. I don’t know if it’ll be possible to end up with equal length control arms but something closer to that should be possible. I’m using narrower 255/75R17 tires so I can afford to push the wheels at least 1” outboard or a little more.

A big advantage of this, in my mind, would be the ability to use the existing brake system and sensors (my ML500 has Brembo brakes). Machining new knuckles will be complex but within my capabilities and I’ve done it before.

A solid axle conversion would be cool though for the ability to install lockers, which would be a huge improvement. If you swapped to a different transfer case as well you could just eliminate the ETS system with no downsides off-road. Something like the NP243 (or is it 242?) transfer case found in Jeep XJs and ZJs would be my preference, having both AWD and normal 4 Hi and 4 Low along with 2wd functions. Combine that with an automatic locker in the rear and a selectable locker or Torsen limited slip in the front and you’d have a far more capable vehicle than the ML is in stock form.

Overall the solid axle conversion may be easier and ultimately better off road, while the longer travel independent could be a little more seamless with better pavement manners. Either one should be a good option to pursue and I’m interested to learn more about your progress as you move forward on this.

 

Hi John. I appreciate your comments here and am in full agreement about the weaknesses of this suspension system. (For background I’ve been an automotive test engineer for about 20 years and also do my own suspension work and tuning/valving on my off road powersports vehicles.)

I know many of the die hard Mercedes fans don’t like to hear it, but you are right about this suspension, it’s weak and has limited travel, but also very poor geometry which would prevent good performance even if travel is increased.

I’ve considered building a longer travel independent suspension for my ML, incorporating better geometry to maintain better tire control across the whole range of travel. Of course that’d require different upper control arm mounting points for sure, and custom knuckles to reposition the ball joints and move them outboard. I don’t know if it’ll be possible to end up with equal length control arms but something closer to that should be possible. I’m using narrower 255/75R17 tires so I can afford to push the wheels at least 1” outboard or a little more.

A big advantage of this, in my mind, would be the ability to use the existing brake system and sensors (my ML500 has Brembo brakes). Machining new knuckles will be complex but within my capabilities and I’ve done it before.

A solid axle conversion would be cool though for the ability to install lockers, which would be a huge improvement. If you swapped to a different transfer case as well you could just eliminate the ETS system with no downsides off-road. Something like the NP243 (or is it 242?) transfer case found in Jeep XJs and ZJs would be my preference, having both AWD and normal 4 Hi and 4 Low along with 2wd functions. Combine that with an automatic locker in the rear and a selectable locker or Torsen limited slip in the front and you’d have a far more capable vehicle than the ML is in stock form.

Overall the solid axle conversion may be easier and ultimately better off road, while the longer travel independent could be a little more seamless with better pavement manners. Either one should be a good option to pursue and I’m interested to learn more about your progress as you move forward on this.

swapping the transfer case to a full manual tcase would be ideal, and yes, that would eliminate 4ETS, which would be optimal. That is a whole separate subject however and maybe worthy of its own thread (which I have yet to create). So far, I have been eyeing these guys. I bet they can make a transfer case with the correct interface to the W163 transmission. I bet it helps that the Jeep JK uses the "same" transmission as the W163, and they make transfer cases for that Jeep...

Only parts I replaced in the front suspension were shocks (Bilstein B4), sway bar bushings and outer tie rod ends in 20 years. The rest of the stuff is still bolted at the factory. After 213,000 miles, this heavy vehicle still rides great and steers very tight. How can that be a weak suspension if they last this long? Suspension is one of the very few things I applaud in this car because after 20 years, it still feels like a car of 2010s. Are you talking about off-roading?

Yep, this gripe of mine only applies for off-roading. Someone must have added "for off-roading" to the thread title, which is helpful, so thank you to whoever did that!

Ditto on @Merzatt comments.
These were never designed for offroading as defined by the OP.

I'm not sure what the engineers were thinking when designing the W163, apparently it was supposed to be some sort of successor to the G-wagen which was most definitely an off-roader, but obviously not designed to handle the terrain the G-wagen could. The interesting thing to me is the apparent gap in capability between the 4x4 system and the suspension in the W163. It's like they don't match.

Okie dokie. I wasn't very clear. We would enjoy the pictures of you doing that...

My build thread is here.

Clearly we spend out $ anyway we please, but if I wanted to get into off road trekking, why not pick up a vehicle made such a purpose. There are so many better options for off-road fun. Better yet get an ATV, Quad, or cycle.

You bring up a solid point. In other words, why the heck don't I just buy a Jeep?

In short, because that's what everyone else does, and that's boring. I got this W163 from a friend for free and in excellent shape, and I love fabricating and I want to be the only guy with a Mercedes on the trail dragging Jeeps out of the mud. Besides, how cool would it be to have a Mercedes SUV with a ford rear axle, Jeep front axle, and Chevy engine? Darned cool, that's what. (5.3 swap miiiiight be in the future, if the M112 ever craps out)

 

Only parts I replaced in the front suspension were shocks (Bilstein B4), sway bar bushings and outer tie rod ends in 20 years. The rest of the stuff is still bolted at the factory. After 213,000 miles, this heavy vehicle still rides great and steers very tight. How can that be a weak suspension if they last this long? Suspension is one of the very few things I applaud in this car because after 20 years, it still feels like a car of 2010s. Are you talking about off-roading?

 

Yes, off roading obviously (why else would someone consider a solid axle swap?). That introduces demands on the suspension that would never be seen in road driving, in both durability and performance.

 

Ditto on @Merzatt comments.
These were never designed for offroading as defined by the OP.

 

And?

Does that mean it shouldn’t be discussed?

 

Clearly we spend our $ anyway we please, but if I wanted to get into off road trekking, why not pick up a vehicle made such a purpose. There are so many better options for off-road fun. Better yet get an ATV, Quad, or cycle.

 

So here is what I am doing: I am eliminating the slotted holes by welding in heavy duty thick washers (that are very tight-fitting, literally 12mm ID) in the outboard positions. This will make sure the upper A-arms stay in place and don't slide around ever.

I bought longer bolts (M12x100) to accommodate the two extra washers per bolt as well.

Here is one of the factory slotted holes with a bolt (partially) installed.

Here is an example of a washer that I welded in place. Please excuse the ugly weld. It's dang hard getting the welding nozzle in there...

 

That should hold her!

 

And how are you going to do an alignment?
I beat the crap out of mine off road and I have never had them move on mine. And, I think it works rather well off road exploring. Not a a rock crawler, but it does remarkably well.

 

And how are you going to do an alignment?
I beat the crap out of mine off road and I have never had them move on mine. And, I think it works rather well off road exploring. Not a a rock crawler, but it does remarkably well.

Awesome front bumper and skid plate! Did you make them yourself? I still don't have tube bending and notching tools that would have been required to make your bumper...

I would venture to speculate that your level of crap-beating might not be the same as mine if your upper control arms have never moved, either that or or your upper control arm bolts are cranked down so tight and rusted in place that you've managed not to move them. That said, you are right, the ML does do remarkably well off road, although it's no rock crawler.

Fixing the upper control arm mounts only fixes the camber (although you can technically screw around with toe and caster by adjusting the upper control arm side to side, but I'm pretty sure that wasn't the intended purpose). Toe can still be aligned independently on all 4 wheels; on the front w/ tie rods, rear with the "toe radius thrust arm bar thing" that has the eccentric bolts.

Also, I plan to do solid axles next summer, so I only need to "get by" until then, hence the low-budget quick and dirty job I did.

 

Yes, I built it all myself. No notcher, but had use of a friends shop that had all the bending equipment. My bolts are new and torqued to specifications. If I was to ever have a problem, I would make an eccentric flat washer and a stop. That way the camber can still be adjusted, but it is more of a positive stop. Many cars have this setup and one might find something that works in the wrecking yards.

I mainly use mine for backcountry exploring. Lots of rough stuff here in the Idaho Rockies, but I take it slow and easy.

 

 

Good example of some of the limitations of the system.

Notice all the jerking and hesitation - even a single locker in the rear on a normal 4wd system can let a vehicle move through an obstacle like that smoothly. If it’s uphill and low traction, maintaining that momentum is important. The ML on the other hand has a tendency to lose momentum and traction a lot in the rough stuff because of how jerky the ETS system is off road. That’s why I’d like to figure out a locker for mine.

The lack of articulation is the other big point; that tipping from one side to the other can be very dangerous in some conditions. Something like my XJ on the other hand can walk through a ditch like that and stay a lot closer to level the whole time, and never have a wheel off the ground. In real off-road conditions that not only maintains traction a lot better, but is much more stable and safer too, not to mention smoother. That’s why improvements to the ML suspension are important for those of us who like to go off-road. Even little things like removing the sway bars can help a lot.

 

I guess one gets to the point of so much flex, one needs lights and a camera down below. Would be fun to see an ML on that trail.

 

I guess one gets to the point of so much flex, one needs lights and a camera down below. Would be fun to see an ML on that trail.

One can do that, sure, but I don’t think that’s what John or I are talking about here. Articulation can be greatly improved while still having a very streetable SUV, and without going to extreme levels of building something specialized for off road only.

It does seem that several of you here are acting defensive of the ML, as if we should expect it to be perfect in stock form. It’s not, but neither is a Jeep, Land Cruiser, Bronco, etc. The big difference between those and the ML is there is almost no aftermarket support for suspension improvements on the ML, so we are left with discussing it here to figure out how to make it do what we want. The “just buy a Jeep then” comments don’t add any value to that end, and I suspect are coming from people without any real off road experience anyway.

Personally I’m not interested in turning the ML into an off road only rock crawler or something like that. I’m interested in improving its capabilities on our local logging roads and trails in the mountains, while maintaining its ability to drive comfortably and safely on the street. That’s not an unreasonable goal, and discussing it here doesn’t need to make anyone defensive about the ML’s capabilities in stock form. The ML has a very street oriented suspension that is supplemented by electronic controls to get some rough terrain capability back, but it definitely has a lot of room for improvement.

 

Full support from my side; I love to see how others mod their ML's. A solid front axle would be quite unique. I'm impressed with the crazy flex Cherokee above and if one achieved 1/4 of its' articulation in an ML, I'd say it's a success.

This gal knows how to have fun!

 

All kinds of great ML off-road vids popping up in this thread! This is good stuff!

All that said, the 4ETS system is still far superior to the awd system in my Subaru (for example). If I were to put two opposite corner wheels in the air in my Subaru, I would be dead in the water. At least the W163 powers through eventually.

However, What Yondering says is 100% correct, true lockers are far superior to the 4ETS system.

I think overall it would be fair to say that the ML is a much more capable off-roader than most folks would expect, but there is also certainly a lot of room for improvement!

 

Yep the ETS system is pretty good for what it is, just not as perfect as a lot of Mercedes fans claim. It’s great in the snow for example, whether in city streets or up in the mountains on smoother logging roads; been doing a lot of that the past week or so. It’s deficiencies don’t really show up until you get into more serious off roading than most here would do, which is why few people seem to understand the value in improving it.

 

ML plow without the plow.

 

I watched a youtube video once of an ML vs a Hummer. You know, the biggun. The ML did a rock crawl over a v shaped trail, solid rock on each side and you know that climb had to be compressing the wheels inward but nothing broke and it made it. The Hummer front wheels folded like a wet paper bag halfway up the trail.

 

For years, I drove an AWD Eagle Talon. With it's almost dead-on 50/50 weight distribution and low center of gravity, I used to piss off pickups and SUVs by zipping by them in deep snow all the time. My chin spoiler, both differentials, and the transfer case would leave grooves in the snow if it was deep enough.

 

Hammond says this suspension is fairly strong...

 

I do agree with the weak points of the W163 suspension, although I do find it very hard to believe that it was not designed for off-roading at all. This car was never made to do serious off-roading, but I think that they did keep off-roading in mind, isn't it accepted at this point that the M class was supposed to replace the G wagon at some point, but they backtracked on that? TBH if it wasnt designed for offroad then I can't see why they bothered with a low range gearbox and the special 4ets mode that acts differently when in low range, or for example a torsion bar front suspension rather than just coil overs like the rear. Merc prob kept going through deep snow or dirt trails in mind for example, this car is really really strong stock in deep snow.

 

There is someone on the sprinter-source forum who fitted a lockable jeep transfer case to the back of their 722.6 trans. This tcase would bolt on to the w163. But the low range is different ratio so some trickery is needed for the 4ets system. But I reckon a locked centre diff would fix the momentum issues with 4ets. It does fix it on the LR Discovery2.

The other thing is the upper A arm camber slots. Couldn't you grind the slot longer but downwards on an angle towards the axle centre?

That would give some correction to both the camber and the arm angle at the same time?

 

I think these guys got a good setup.

https://img.favcars.com/mercedes-benz/m-klasse/mercedes-benz_m-klasse_2007_images_2.jpg

 

Oh yeah, Alex in Chicago is back with the ML!

 

<spoiler alert> I note that he suffered a failure due to the upper A arm angle.

I wonder if extending the camber slot downwards as well, instead of just outwards, would help with the angle/stress its under when lifted.

 

<spoiler alert> I note that he suffered a failure due to the upper A arm angle.

I wonder if extending the camber slot downwards as well, instead of just outwards, would help with the angle/stress its under when lifted.

Well in the video he said the nut holding it failed and was gone but when he used another nut from the top of the shock it was totally fine. So technically it would be a failure of the nut. Either way it's probably due to the stress/angle as u said, but I guess that would mean that if he had stronger nuts he would be fine? The ball joint was fine....

 

I think the ball joint would have to be shocked out of its taper first, so the nut working lose seems more of a symptom than a cause.

I imagine something is going to actually break pretty soon, if it is being regularly subjected to enough force to break that taper.

 

At a minimum he’ll be replacing that boot. Is a Mercedes boot available or does one just buy the whole shaft. No doubt, Dorman has a universal CV boot to more or less fit.

 

Another pretty good video.

 

And how are you going to do an alignment?
I beat the crap out of mine off road and I have never had them move on mine. And, I think it works rather well off road exploring. Not a a rock crawler, but it does remarkably well.

View attachment 2728767

And how are you going to do an alignment?
I beat the crap out of mine off road and I have never had them move on mine. And, I think it works rather well off road exploring. Not a a rock crawler, but it does remarkably well.

View attachment 2728767

Where would i get a font bumper like that??

 

The demand for a W163 off road bumper must be really small. I doubt there is a click the mouse and it ships choice. And, these are often fabricated better than store bought anyway.

Find an off road shop and get it made. Leave room for a winch.

And, for the beginner off road capability is mostly around articulation and ground clearance and not so much around sturdiness of the suspension parts. And, a fabricated long arm suspension would be the cat's ass on a W163.