The Platform: 2002 Mercedes-Benz ML500
Project Greta is my second overland build based on a 2002 Mercedes-Benz ML500, chassis code W163. This platform features a smooth, purring 5.0-liter V8, snugly mounted to a body-on-frame chassis, producing an impressive 288 horsepower. It comes with full-time four-wheel drive supported by a clever 4-ETS simulated differential lock system. Mercedes even included a BorgWarner two-speed transfer case with a low-range gear. Good lawd, what have those Germans designed?
It’s surprising that more people have not modified this vehicle. As of this writing, the first-generation M-Class is one of the cheapest luxury SUVs you can pick up on the used market. Many will be pleased to know that the price isn’t reflective of the platform’s durability. The drivetrain has proven itself capable of absorbing countless miles while still running strong. Simple, basic maintenance is all that is required to keep one of these on the road, and standard replacement parts are in line with Jeep and Toyota in terms of cost.
If you plan on modifying one of these, there is a bit of work involved, but nothing extreme. This article will share some of the work I’ve done and the lessons learned over the course of a few years of owning this vehicle.
Suspension Considerations
Serious off-roaders may frown when they hear that the ML has independent suspension on all four corners. IFS (Independent Front Suspension) and IRS (Independent Rear Suspension) setups are not known for allowing as much wheel articulation on uneven terrain compared to a straight axle. However, the tradeoff is that independent suspension generally provides more comfort and better handling characteristics on-road. It’s debatable whether independent suspension feels better off-road compared to a straight axle and likely depends on the hardware configuration (shocks, torsion bar stiffness, sound-deadening materials, tire size, etc.) and the engineering of your specific vehicle—all of which can shape your subjective experience of “comfort.” I would know — my first project was a Jeep Cherokee.
Weight and Comfort
The M-Class weighs 4,630 lbs for the ML320 and 4,652 lbs for the ML500. That’s only a few hundred pounds less than a 100 Series Land Cruiser (5,115 lbs) of the same era, but the M-Class costs about as much as a Jeep XJ while offering more interior comforts. The ML500 I’ve built features a dark leather interior with heated seats, a Bose sound system, sunroof, front/middle/rear 12V power outlets, a fold-up rear hatch cover, and 80.2 cubic feet of interior cargo space with the seats folded down. This means there’s plenty of room for recovery gear, extra tires, jacks, coolers, firewood, camping gear, and even a dog. As a semi-luxurious, long-distance exploration platform, it starts to make sense. I think the kids call that “overlanding.”
Current
- Tires – 285/70R17 BFGoodrich KO2 All-Terrain T/A (basically 33s)
- Issues: Moving from 35s to what is effectively 33s might seem like the “wrong” direction to go, so let me clarify:
- Exploded transfer case: After 6 months on 35″ tires with a few mostly mild off-road adventures in mud and snow under my belt one of the smaller gears in the transfer case decided to try and break free from the rotating assembly while I was crawling at a relatively slow pace up a snowy hill. This level of damage is the end of the line for whatever trip you’re on and requires a tow, as you will have no drive to any wheels forward or reverse. Everything depends on that transfer case sending power to the front and rear wheels.
- Front fender rub at full wheel lock: While not terrible it’s stupidly annoying when you can’t use the vehicle’s full turning radius. Part of the advantage of the ML platform is that it’s a relatively compact SUV but it starts to feel really big when you have to make a 7 point turn just to get in and out of parking lots without rubbing.
- Road feel: The vehicle already felt heavy on acceleration and going around corners but with 35s on stock gearing the additional heft felt like it was straining the drivetrain in ways that did not feel sustainable.
- Un-utilized potential: The KM3 is a great tire – on the right platforms. It has relatively low road noise for a mud-terrain, it’s aggressive tread provides a ton of grip, and it’s very durable but… the ML cannot use it to it’s maximum potential because, as good as 4-ETS is, it’s not a replacement for true differential locks. There I said it. Especially after destroying a transfer case I lost confidence in the ability to send it in a way that would really use those mud-terrains.
- Solution: I had KO2s on the Jeep for nearly 5 years. The KO2 is also durable, has a great tread pattern, virtually no road noise, and comes in different sizes for large and small applications. In my opinion this is the tire people should be using for overlanding-type vehicles. You don’t need mud-terrains when 90% of your driving is on pavement and gravel roads. You don’t need a 35″ tire in order to make it over obstacles to get to 98% of trailheads and camping locations. Let me be clear – a good set of all-terrains is leaps and bounds better than a street tire on the ML. The all-wheel drive can fully use the extra traction that an all-terrain tire provides. It just can’t fully utilize a mud-terrain to the same level that a front/rear diff-locked vehicle with a built drivetrain can.
- Issues: Moving from 35s to what is effectively 33s might seem like the “wrong” direction to go, so let me clarify:
- Wheel Spacers – 50mm 5×112 hub-centric black anodized aluminum (eBay special)
- Issue: I’m continuing to run these wheel spacers for now. A 33″ tire is still quite a bit larger than the factory tire size, but the width of the tire is more aligned with factory sizing. The tires do poke out from the fenders about 1-2 inches so I really should look at pulling the wheel closer to the hub in order to keep debris inside the fender well instead of running up the sides of the vehicle.
- Solution: With the smaller height and width of the KO2s I can likely get away with a thinner spacer and may look for replacements in the future. I need to take some measurements to see what the minimum spacer size would be that would not introduce fender rubbing.
Past
- Tires – 35″ BFGoodrich KM3 Mud-Terrain T/A (35×12.5 R17)
- Issue: Ground clearance and traction were two weaknesses that needed to be addressed. In fact, this entire build was based around these tires and to improve the off-road prowess of the W163 platform. 99% of the M-class vehicles that you see on the road will have summer or all-season, low-profile tires because that’s primarily where this Mercedes product was designed to be. The M-class isn’t as off-road capable from the factory as the G-class, but it can be brought closer to that status with tires.
- Solution: Fitting the largest tire possible without fender trimming or a body lift made a significant difference. With a few minor suspension tweaks, 35″ tires will fit and are functional. This upgrade improves ground clearance across the board as well as approach and departure angles. The front bumper requires a slight amount of trimming or it can be removed entirely. The rear bumper doesn’t need any trimming, but I decided to cut some of the unnecessary bits for a slight improvement in functionality.
- Wheel Spacers – 50mm 5×112 hub-centric black anodized aluminum (eBay special)
- Issue: I wanted to retain the factory 8.5 x 17 Mercedes wheel which have a 52mm (or +2″) positive offset. Because these tires are so much taller and wider they need to be pushed out for proper clearance.
- Solution: A slightly negative or neutral offset wheel would be ideal, but spacers also work.
Current
- Front Shocks – Rancho RS9000XL (RS999187) for rear of a 1997 Toyota 4Runner
- Issue: The factory front shocks only have 2″ of travel. Length is 13″ compressed and 15″ extended. Greater for mall crawling, bad for rock crawling.
- Solution: The venerable Jon Kucyj discovered that a rear shock for a 97′ 4Runner is a great alternative when cranking up the torsion bar to fit larger tires. Specifically, the Rancho shock he recommends in his video has 7″ of travel, 13.5″ compressed, and 20.5″ extended – plus it’s 9-stage adjustable damping to fit various applications. The torsion bar needed to be re-indexed, cranked up, and upper control arm camber bolts adjusted to straighten the tire out, but it fits 35″ tires with minimal scrubbing on the inner fender liner which can be trimmed or re-molded for clearance.
- Rear Strut Spacers – 1″ lift high density polyurethane by Infidel Garage
- Issue: While the front suspension utilizes a torsion bar and shock absorber setup, the rear is an all-in-one strut assembly. So how do you get lift out of such a compact, non-adjustable component?
- Solution: Spacers! 1″ is the ideal amount to fit 35″ tires with only minor rubbing on the inner fender liner. Ideally, there would be a kit with adjustable coil-overs paired with beefy upper/lower control arms. I haven’t found it, yet.
- Body Lift – 1.25″ high density plastic spacers and extended bolts & washers (12mm x 1.50 pitch x 140 mm)
- Issue: After a re-indexing the torsion bars in the front and cranking them up to achieve the maximum amount of lift I found that the control arms did not have enough adjustability for a proper alignment without physically cutting the adjustment slots to allow the tire to additional positive camber. I also discovered that the 35″ tires were still tucked in to the fenders super tight and rubbing in several places. One other minor annoyance was the winch engagement knob required opening the hood in order to switch it, but is no longer an issue with the body lift.
- Solution: A body lift can sometimes be a cheap, easy way of getting some additional fender clearance when suspension adjustability has reached it’s limit. This is a relatively easy mod to do on the ML if you have the tools to lift the body off the frame just a few inches to stuff those new pucks in there. You will need 10 bolts & washers, preferably Grade 8 sized 12mm x 1.50 pitch x 140 mm for spacers with a thickness of 1.25″. I did not have any issues with electrical connectors or rubber tubes needing to be adjusted for this lift. The three pieces that needed adjustment were:
- The radiator upper mounts which needed to be extended with some longer rubber pieces I had laying around.
- The transmission lever which has built in adjustability and can be lengthened or shortened as needed
- The grill air-intake pipe which simply needs to be re-positioned slightly so that it lines up with the front grill better.
Stage 1
- Custom Prerunner Front Bumper by Infidel Garage
- Issue:
- This entire build revolves around fitting 35″ tires. The stock front bumper can be trimmed slightly around the edge closest to wheel well to prevent the front of the tire from rubbing, but I opted to just remove the bumper entirely. Even with the extra lift and ground clearance the stock bumpers hang down much too low which decreases approach and departure angles. (pictures coming soon)
- Issue:
-
- Solution:
- First, a history lesson – the term “prerunner” has its roots in motorsport. It refers to a vehicle that is used to pre-run, or scout, an off-road race course ahead of the actual race to get an understanding of the terrain. These prerunners were often simplified, stripped down versions of stock trucks with a few light modifications to give them the same dimensions and capability of their race counterparts. One of the easier modifications to make to the bumper region is the addition of a simple, tubular design with skid plates that offer protection to critical components in harsh conditions while maintaining a lighter overall weight and maximum clearance. In the late 90s and early 2000s, the non-racing off-road community began adopting these stylistic queues due to their functionality and aggressive aesthetic.
- I think the prerunner look fits the ML nicely. It’s already a heavy platform and the larger tires are not helping with that, so a minimalist design for the front bumper felt like the finishing touch for the front end without adding a ton of extra sheet metal. I also wanted to be able to attach a winch that was easily accessible but tucked as far back and high up as possible without sacrificing the precious degrees of approach angle that were gained over the stock bumper. This design of bumper also has more options for customization around recovery points and lighting locations.
- Solution:
- Trimmed rear factory bumper
- Issue:
- The bumper was already cracked and starting to fall apart plus I wanted to create a slightly cleaner, more aggressive look in the rear.
- Solution:
- I trimmed with a dremel along the natural lines of the bumper to come up with a natural shape that, in my opinion, doesn’t look too bad. It also exposes the factory rear recovery point that’s usually hidden behind a plastic door.
- Issue:
Stage 1
- Smittybilt XRC Gen3 12k Comp Series Winch with Synthetic Cable
- Issue: A winch is one of those tools that you hope you don’t have to use, but it’s very nice to have when you’re good and stuck.
- Solution: So how do we know what size winch to fit to an M-class? Take the gross vehicle weight rating (GVWR), this is the weight of the vehicle fully loaded with gear and passengers, and multiply it by 1.5. The curb weight of the W163 is 2,093kg, or 4,614lbs, but the gross weight is 2,870kg, or 6,327lbs. Using the gross weight for this equation we get 9,490lbs. In theory, a 10,000lb rated winch would be sufficient, but with larger tires, steel bumpers, and probably a roof top tent from time to time it seemed wise to go to the next level with a 12,000lb Smittybilt winch. To shave off a bit of weight I jumped straight to synthetic line.
Showing 39 comments
I am still wondering how is your font diff performing. The center one, i broke 4, then I welded some pinions of the inner planetary gear. Front diff…until now I broke 2. The idea is that the body and suspension is capable but the drivetrain…oh my god!
I am running 31 bf mud terrain, and I do lots of mountain roads…but after almost every meeting, the car is K.O. …it`s like driving a plastic driven SUV. Give me an advice…
To date the front and rear differentials have survived a year of mild trails, long distance travel, and a couple snow runs on 35″ tires.
However… the transfer case (center differential) died after 5 months with this setup and had to be replaced. Fortunately, used transfer cases for this platform are relatively inexpensive and appear to all be interchangeable between the models (including the AMG ML55). At first glance there did not appear to be strength advantage with some transfer cases over others. Hopefully somebody can correct me here if they are more knowledgeable.
I’m working on a full write up of the transfer case damage and am curious if there is a way to rebuild and/or increase the strength of the internals.
Great to see an interest in a hidden gem like the W163. I have some experience with suspension geometry. As W163 does have a limited travel it is best to leave it alone and utilize all of its range. Raising or lowering a vehicle drastically alters the roll center and therefore stability and maximum inclination angles. With the roll center altered spacers and wide tires do nothing for stability. To accommodate larger tires a body lift is necessary and it alters the center of gravity minimally. With 33″ tires full range of up and down travel is rub free with a 1.5″ body lift. I find 33″ tires adequate and fuel economical. In the rear a higher spring rate coil will give some lift but most importantly cargo capacity. On the front a slightly longer travel shock is nice. A 0.75″ longer travel translates in 1.5″ tire travel which gives more steering control on uneven terrain. The shock absorbers set the down travel limit and prevent the CVs from binding. This vehicle has had great success in international cross country rallies like Dakar and others. I have used their setups as a guide. My ML430 is a daily driver and also used for off road travel, “overlanding”.
What you use in front and what springs in back
KYB MonoMax 565102 in front, shimmed lower mount. Many say that it is comparable to Bilstein B6 with slightly shorter life but with .75″ longer stroke results in 1.5″ extra travel. I have a stock bumper so it is a great match and it feels great on and off road. Torsion bars to level off with back, no reindexing needed unless you have 200Kg hanging off the front. That means that the torsion bars are nicely preloaded and are matched for the load they carry with full suspension travel.
Bilstein B6 and King Springs KMRR-91SP in the rear give 1.5″ lift and 300Kg more carrying capacity than stock springs. Camber adjustment slots lengthened 3/16″ to allow for free adjustment without the bolt resting at the end.
1.5″ body lift with 3″ diameter UHMWPE spacers.
Wheel alignment done with 400Kg payload. Stock payload is 600Kg with King Springs +300Kg for a total of 900Kg payload. Track is stock width, no spacers.
Love how solid this thing is. Bought my ml320 with 80k, @7 yrs ago for $8k. 167k mi and worth @$5500 now…outside of maintenance which i do (fluids, plugs, belt, brakes) I’ve spent less than $1000 on an ac repair and some other module. stellar results which seem to be unusual.!
Great snow car and planted during the rain. Cant ask for too much more.
I just bought an ML430 to build up. The 35s look awesome, but wondering if anyone can point me to good photo comparison of 31s/33s/35s? Also, it looks like rear bumpers made for Jeep TJs will mount to the x163 with some drilling. Has anyone tried that already?
Of course I meant w163. My main reason for looking at rear bumpers is to have somewhere to mount my spare. Other than custom, what solutions have you seen or thought of? I found this made for an H2 https://www.amazon.com/dp/B08GLLKDML/, which I’m thinking could be bolted to the ML430 sub-bumper, then trim the stock bumper around it.
Wolfgang’s ML Page has very nice comparisons and figures with some photos. These are archived pages so sometimes when you copy and paste the link it does not take you to the right place. If you open the link bellow by right clicking on the link and choose Go To that should take you to the correct page
http://web.archive.org/web/20070705030605/http://www.whnet.com/4×4/offroad.html
Do read all his pages, they are very informative on W163.
MB full size spare tire carrier was simply bolted to the rear of frame by two bolts on swivel side and two on locking side. This tells me that the steel bumper behind the plastic cover is strong enough to carry the weight. This factory spare carrier option was popular in South Africa. Their roads can be rough once outside the cities.
I like what this guy did with his Subaru Forester. He built swing outs but kept the stock lightweight plastic bumper. Here is the link
https://www.youtube.com/watch?v=ZMF4eGBLHsA
Thanks for the links and feedback. I also found the Offroad Mercedes Group on Facebook which has a lot of examples of what people are doing with their MLs.
Love how solid this thing is. Bought my ml320 with 80k, @7 yrs ago for $8k. 167k mi and worth @$5500 now…outside of maintenance which i do (fluids, plugs, belt, brakes) I’ve spent less than $1000 on an ac repair and some other module. stellar results which seem to be unusual.!
Great snow car and planted during the rain. Cant ask for too much more.
I appreciate all your comments and advice. I rechecked it again and determined it was indeed a head gasket issue. I ended up selling it. It just so happens there’s a ML 500 parked up the street and I made an enquiry if it is or could be for sale.
Now having hands on experience I know what to look out for.
Anyway if it works out I’d like to follow your lead and build.
Thanks again
I’m at a crossroads with my new purchase 2000ML430
Been trying to root out some gremlins. I’ve had multiple misfire codes and decided to do a chemical combustion test through the radiator reservoir and sure enough the color changed from blue to yellow indicating some engine block coolant leak. What I can’t figure out is the oil is clear as is the exhaust and it seems to run good with plenty of power.
My build is on hold until I can know for certain if my ML is a keeper or a dud.
Curious if anyone has had a similar experience or have any insights.
Much appreciated
I am not an expert on the M-class nor am I a long time owner. However, coolant in the combustion chamber is typically due to a head gasket beginning to or already has failed. Coolant in the combustion chamber would throw off the air/fuel ratio and could cause a misfire event. If the head gasket scenario is true you can likely replace the gaskets before any additional damage occurs. A couple questions to consider:
Have you performed a compression check on all cylinders?
Have you inspected the spark plugs for unusual residue/discoloration?
How many miles are on your motor?
Is this a common issue for the ML430 in particular?
Youtuber “legit street cars” mentioned he was looking into retrofitting a rear limited slip differential from a jeep Cherokee. It’s been a month since he made his last video on his ML55, I hope he comes back to it. Have you considered putting a locker yet?
I would love to see that video if/when he does it. While 4ETS is an interesting concept and functions fairly well, a mechanical rear locker would be helpful.
Check out the YouTube channel “legit street cars”. He is currently doing a w163 offroad build with 35 inch tires.
Subscribed!
Glad to see one of my bumpers put to good use bro! If you have any issues with it, let me know. I bash mine but always welcome more input. Follow this guy and look up ML4DIRTY on YouTube for more fun. Then let me know when you want to join the cool kids club @ Infidel Garage facebook.
Best of luck Aaron!
Hey there! This is an amazing build!
I am about to pick up a Mercedes ML 500 next week and the front bumper is already broken so I would like to replace it with a steel front bumper similar to what you have!
Do you have a link or something for your front bumper?
I would like to buy the same one and cant find anything online!
Thanks in advance!
Hi Ian, I recommend joining Jon’s Facebook group “The Offroad Mercedes Group”. Seek Jon out and see if he’s still building these bumpers. I can attest that they are rock solid and super functional.
Concuerdo con todos tus comentarios, yo estoy en proceso de preparación de un ML 500 año 2005, gran desempeño en trial y dunas. Al precio de estos mercedes es una gran opción.
Gracias, Francisco. Parece una plataforma sólida.
Check out these guys
Mercedes Benz Desarrollo Y Competicion
I ended up buying a 2000 ML 430. I measured the inside with the rear folded down seems to have enough room with the seat forward a bit.
I emailed Infidel Garage never got any response. I was wanting his front bumper and possibly the roof rack. I’ll have to look around.
Thank you for your helpful advice
Hi Rich send me your email please, I have a winch bumper, let me send you some pictures, also lift blocks
Mine is [email protected]
Hey Luis, I am also interested in getting a front bumper from you! How much do you charge?
Ian I dont sell bumper because the one that I make for mine is very difficult to install, you need to cut stuff and drill chassis etc..
Sorry for the late response thats why I left my email if you want to see pictures
One more question.
I’m 6’2” and potentially will be sleeping in it. With the rear seat folded or even removed do you think I’d be able to stretch out and lay down?
I’m unsure of the exact dimensions in the rear cargo area with the seats folded down. It feels large, especially compared to my Jeep Cherokee XJ. I’m 6’5″ so at some point I should probably test this to confirm!
You’d have to lean the front seats forward and fill the gap with something / or an inflatable air bed. I’m 5’10” and I’m not quite touching both ends with a 1.88m x 1.2m air bed jammed in the back (really jammed). I’d even say that your driving position would be compromised, if you have long legs, as the room up front with the rear seats down is compromised. So, you’re looking at having to convert the mid row every day to fit into the driving position too. Not a deal breaker, but you have to decide how much comfort you want. Also consider the 1st gen GL class with offroad pack. For overlanding, it’s almost as capable. Low range, though the transfer case is not quite as strong, you won’t break it doing overlanding (just be careful on sand and mud). GL is a palace. Much better road manners. If you go the W163, your daily conversion is to move your driver chair, fold down the seat behind you, move your stuff from the back to the driver’s area (same for your passenger, you can just about sleep 2 in the rear). So your “inside the car gear” is limited to what you can fit in the footwell and on the driver seat. The w163 is crazy strong; i took it out to a salt lake (Lake Gairdner, South Australia) It’s a 4 hour drive at 60kph or 40mph from the last tarmac. I’m on 33″ tyres (West Lake SL309 LT285/70/17, rock dressed as a tyre) it was bone jarring. I was wrecked from the noise and vibration BUT, i hit a rut (actually tree root) at 40kph or 25mph and it just made a loud thud and rolled on. I stopped to check for damage and there was nothing. Whatever you get, aim for 16″ or 17″ wheels for tyre variety. You can’t get spares out bush. Even 17s are hard to find. The late ML with the sport or tow package can’t fit the 16″ wheels. – maybe over the rears… (i have the tow package with the Brembo brakes and uprated rear springs and dampers). Lastly, if you don’t mind reduced head room, build storage up to the height of the wheel arches in the rear so you can make the larger bed flat. First, see if you fit in the driver’s chair with all the seats flat. Much less conversion, every day. Of course, if you permanently convert, then out with the middle row and in with a custom storage solution. you sleep behind the passenger chair, problem solved!
Thanks for the clarity very helpful.
Part of my daily routine lately is searching online car sales. I can’t decide if I should purchase a 6 or 8 cylinder. I see advantages and disadvantages for both. A 6 would offer a little fuel economy and easier to work on under the hood and a bit lighter. The 8 obviously has the power. Going with bigger wheels I just don’t know about going with the 6. Any thoughts?
I can’t speak to the driving characteristics of the V6 motor in the W163, but with the ML500 and the 5.0L V8 it scoots along even with 35s and heavy factory wheels. It’s not fast, but it gets out of it’s own way and cruises nicely on the highway. I would question whether there is much of a difference in trail driving when low range is activated. I suspect the advantage of the larger motor is the ease at which you can get to a trail, but the playing field levels once you’re crawling. The V6 has the weight advantage, and may also have the fuel economy advantage as well unless it burns more fuel trying to turn the larger tires.
Hi Richard I have a V6 with 32″ by 9.5″ 10 ply very heavy tires, and the V6 is not bad, does accelerate good but does not have the low end torque you expect from a V8, still drive at 80 no problem, little vibration because are mud tires, and the MPG’s are around 15 in town at 70 mph the truck runs at around 2600 rpm’s.
I like better the V6 because of the lower axle gear ratio
Mine its getting heavy also because I have a winch bumper around 100 lbs and I only indexed 1 notch the front torsions bars
I too want to build me a off road ML like you. I’m a bit fuzzy on the suspension.
Thank you for supplying the Rancho shock part numbers for front and back.
I was thinking of searching for Bilstein with reservoir shocks. Haven’t searched yet. Do you know of any other shock options?
Do I or should I add a spacer to the front springs?
Thanks
The front suspension uses a torsion bar that can be re-indexed and bolt tightened to raise or lower the front end of the vehicle. To fit 35s I’ve re-indexed by two teeth/splines (check out https://www.youtube.com/watch?v=JSB2ioVjrFg) and tightened the adjuster bolts on the torsion plates to set the exact height needed to clear the tires without rubbing. There are no springs on the front of the vehicle, just shock absorbers. Those will need to be replaced with extended travel shocks. I believe someone in one of the Mercedes Benz forums did find a Bilstein shock with external reservoirs that worked in the W163 platform, but I’m not sure if they had a lift and larger tires. So far I really like the Rancho shocks, but I need to do more driving and adjust the different damping settings to dial in the ride comfort.
Im building my 2001 ml320 lifted already with 1 in block in the back re-index 1 notch the front torsion bars and made a custom winch bumper i will start welding the rear tire carrier, i want to install skinny tires 235 85 16
Cool! I would love to see some photos of your build. Feel free to email them to [email protected].