ccrelan Reader
1/18/14 1:35 p.m.

Hi Everyone- I have had this project going for quite a while now and wanted to try to get the details posted up here. A few years ago, I bought a 95 E320 wagon that was in fairly decent shape. I drove the car for a bit and realized that the head gasket was on its way out. My parts supplier and friend suggested that it would almost be a plug and play if I could get my hands on a 95-96 C36 AMG drivetrain. Lucky for me, I found a decent C36 engine locally. Rather than replacing the headgasket on the leaky 3.2 why not swap in the 3.6???

The C36 wiring harness was not used in our swap as it was cut and unusable. We reused the w124 3.2 wiring harness and swapped over the front pulleys and belt driven airpump from the old 3.2 onto the 3.6. The 3.6 engine came with a electric air pump. If you had a good C36 wiring harness everything would be a direct fit and could also use the C36 ECU- which I did not. The C36 wiring harnesses tend to be more pricey, complicated to find the correct one (three versions made), and difficult to find than the w124 ones. We reused the auto tranny that was already in the wagon. I had a receipt for the tranny being rebuilt fairly recently.

The swap went off fairly easily. I replaced a ton of stock parts while we were in there. Motor mounts, steering components, etc were all done with the engine pulled. I also took the time to POR15 some places that are known to rust on these cars- the battery tray and under the washer and coolant tanks.

The tricky part afterwards was finding someone to chip the 3.2 computer. I ran the stock 3.2 ecu until I found someone who could burn a chip to 3.6 specs. The car ran fine, but was really at stock 3.2 power level. After a long search, Speedtuning USA in MD was able to burn a chip for me. The power difference was significant and I finally got the full power advantage of the swap. I am still currently using the smaller 3.2 crossover pipe even though I have the 3.6 crossover tube. People have debated the power differences between the two, but I don't believe it to be very much. Obviously, having the one stamped 3.6 is infinitely cooler. I am going to be installing 3.6 crossover soon, but need to modify a later style valve cover in order to make it work. The channel inside the later style valve cover needs to be modified via a dremmel. The wiring from the injectors fits inside that channel. The valve cover gasket is currently shot so that will all be done in one shot along with install of a better wiring harness.

The wiring harness in the car is an early replacement harness. I have been chasing a erratic idle for a long time now. The throttle actuator was replaced, injectors cleaned, maf swapped, tune up done, and coolant temp sensor replaced. All of had no effect on the hunting idle. The car runs great other than this one hiccup.

Last year, the suspension was totally rebuilt. 500e sway bars were added front and rear. Early Sportline control arms were done up front. We dropped the rear subframe out in the rear and did those bushings as well. My suspension links were already newish so they stayed. H&R springs were added along with bilstein sports up front. Unfortunately, the drop with the H&R's is a bit up front even with the tallest bump pads. I ran a set of monoblocs with 225/45/17s for a while but got tired of beating up the passenger side inner fender. I have since switched to a set of 16" CLK lightweight wheels with 205/55/16 tires. I have not rubbed since switching and the car drives a 100 times better. The CLKs were something like 12-13lbs a corner lighter than the monoblocs. The drop is still annoyingly uneven. I don't have any options up front unless I swap in different springs. I can lower the rear a bit more with the self leveling control or by switching to smaller rear spring pads. I have a set of 500e springs available to use as well, but am not sure which direction I will end up going in. I really need to buy a mercedes spring compressor as it would make changing springs out far more easy to do.

I bought a bigger downpipe recently and will be installing it up soon. The pieces are all flanged and will make it easy to install. I sprung for a flanged high flow cat and flanged test pipe. Running no cat on the car makes a big power difference. The euro 3.2 engine makes 20 hp more than the US catted version. I found a shop to make me a flanged resonator delete pipe. It will lead into the stock rear muffler which has a 2.5" inlet. I should have this done in the next month and am anxious to feel/hear how it sounds/runs. I also have a second chipped ECU with the highest level of tune that Speedtuning made for the 3.6 engine. I have yet to try it out and am waiting to uncork the exhaust first.

I have left the interior alone aside from a 500e 390mm wheel. My friend donated a rough AMG gen 1 body kit to me. The skirts are fine, but the front and rear bumpers need a lot of fiberglass work. The kit's refurb work is a ways off.

The biggest letdown of the swap has been the old school auto tranny. It is poorly matched to the power band of the AMG engine. The engine really makes all of its power up in rev band and the auto always seems slow to react. In addition, I have a flare between the 2/3 shift that is super annoying. It became evident that the previous owner only had reverse gear fixed and not the entire trans overhauled. There is a K2 spring kit that you can install to help this 2/3 flare, but I have not done it. Last year, I found a untouched 86 300e 5 speed at a local wrecking yard. I was able to crib everything needed to swap things over to a manual. The key parts being the pedal box and shorter drive shaft. I traded my friend the overdrive 5 speed tranny out of the 86 300e for the 16v dogleg getrag close ratio 5 speed. I was able to get in on a group buy for a lightweight single mass flywheel online. It is very light and is great for my swap as I am able to bolt up the stock auto tranny ring gear. This important because the ring gear has the magnets/segments on it so that the car will idle properly and work with the computer. The early cars didn't need the magnets like the later 24v valve cars do. The custom clutch and pressure plate set up should be arriving in the next week.

The plan is to pull the entire drivetrain again. I need to do the wiring harness/valve cover/cross over tube repair. The EGR is a potential cause of the idle issue. It is easy to remove the EGR pipe with the engine out of the car, too. The oil pan gasket needs replacing which again is super easy with the engine out of the car. My friend may be renting some shop space locally so this engine/trans swapping may happen in the next couple months.

Sorry for the rambling and disjointed information. Here are some pics to check out. Cheers- Cory

Subframe out: With monoblocs after suspension redo: Elusive 3.6 crossover tube: These are the CLK wheels on the car before the suspension work: Pics of downpipe: Pics of custom flywheel for swap:

W124_Karl New Reader
1/22/14 1:17 p.m.

And here I thought for certain that I'd be the lone W124 person here when I signed up. A lot of my motorsports-oriented friends think I've lost my marbles. :) They're wonderful cars. It's my favorite of everything I've owned so far.

Please post what you end up learning about doing a manual transmission swap. I've heard of it being done on M103 cars, and even the early diesels, but I don't think I've ever seen a swap into an M104 car. That'd be a real hoot - it's such a great motor.

How terrible a job was dropping the subframe to redo those bushings? My car has very low mileage, but age takes its toll, and I'm curious what kind of terribleness I'm in for.

When you say the drop is uneven, do you mean that the drop is lower front than rear? That's how it looks in the photos, but I didn't quite follow your post. Even so, I wonder if sourcing a set of OE Sportline springs would be a better fit. I've seen a lot of cars on Benzworld with the Sportline springs, along with 8mm spring pads, and they seem to sit nicely without being slammed. Not sure how that works with a wagon though, short of altering or removing the SLS stuff.

What made you choose to use Sportline control arms? I'll be honest, I didn't know there was such a thing. Is it possible that's the difference causing the unevenness?

I've done quite a bit of work to my low mile (60K) sedan, but nothing like this. Recently had to do the water pump - that wasn't as bad as everyone said it would be. I struggled with one water pump bolt, access to which was perfectly blocked by the coolant crossover pipe at the front of the motor…which was held on with a rounded out hex bolt. I also had it completely apart for a repaint. That was tedious but actually a lot of fun, and the rewards were worth it.

Anyway, very cool car. I just adore mine. I've got far more money in it than it'll ever be worth, and that's fine. It's probably not even two years worth of tire budget for the stock class S2000 I used to autocross...

dculberson UltraDork
1/22/14 2:35 p.m.

Sweet car, I've thought about one of these E-class wagons with a manual swap for a long time.

bgkast Dork
1/22/14 2:43 p.m.


ccrelan Reader
1/22/14 10:03 p.m.

W124-Karl- yes, the OEM sportline springs with short spring pads would be the best way to go. The drop in the front with the H&Rs is too much for my liking. The bad part is there is no way to raise the car up any higher as I am on the tallest 4 pt pads up front. I have read numerous posts saying that the H&R's and 17" wheels fit fine, but that was not my experience. The car just did not drive the same with the heavy monoblocs and combined with the rubbing drove me nuts. I do have the 500e springs and may end up using them in the end. I can lower the rear more via the SLS adjustment but would prefer to leave it as it sits. You can cut w124 springs without any ill effects. Some people even use cut R129 springs as they are much stiffer than standard w124 springs.

I chose the early sportline control arms becuase they had the firmest rubber bushings. The later sportline or 500e bushings rubber were not quite as firm as the ones I used. They were not cheap, but the car really does handle much better with everything done. The best way to describe the car before the suspension work was floaty. It is far from what I would describe as harsh as it sits now.

The real key to the manual tranny swap on a M104 is the flywheel. The rest of the swap parts can be found from a 86-88 300e 5 speed. Some of the stuff can be even cribbed from 5 speed 190e. The custom lightweight flywheel is a really trick piece and eliminates the pick up magnet issue. I really can't wait to drive the car with the 5 speed. With any luck, it is going to happen within the next month or two.

The rear subframe bushings were not terrible. It would have went 100 times quicker if you use the benz specific tools for the bushings. As it was, we ended up using some homebrew solution that worked with varying degrees of success. Peachparts has a good tool rental section on their forum.

I also have a very period set of 16" Enkei 92 mesh wheels for the car. I need to get the centers of them painted body color to be vintage cool! I just scored a set of four center caps for the wheels off the classifieds here.

I concur with Karls sentiments about these cars. I have owned tons of cars, but none have felt as well built as this one. It has a special feel to it. I don't want to count up what has been spent either. These cars can be super used car buys if you know what the pitfall areas are.

W124_Karl New Reader
1/25/14 11:22 a.m.

ccrelan, did the rear swaybar upgrade require the removal of the entire subframe? I've read mixed things about that. I imagine you probably did yours when you had the subframe out already anyway, but if I could upgrade to a 500E rear bar, I'd probably do it. Did you find the upgrades to be worthwhile?

I've also seen that the stock rear bar uses plastic endlinks, while the wagon uses metal ones. I think the wagon ones have to bend around something specific to the wagon, so I've wondered about making some of my own, out of spherical bearings. Maybe that'd be an easier upgrade.

They're wonderful cars to drive when they're sorted. It's not what I'd call "sporty" in the no-body-roll, stiffly sprung sense. It doesn't make me want to find the closest autocross to me on a Sunday morning. But it handles well, has a lot more grip than I thought it would, and has great brakes. It's very confidence inspiring and satisfying to drive. Just not in an S2000/Miata/M3/etc sort of way. And I know it'll keep my family safe if something bad happens out on the road.

ccrelan Reader
1/25/14 2:43 p.m.

Hi Karl- yes, the 500e rear bar is definitely worthwhile. I bought my from the dealer for not too much money. The cheap way to go for the front of your car is to pick up a wagon front bar. The wagon front bars are the size as sportline front bars.

The best way to describe things is that my car handles like a much smaller car with all the work done. I read that the H&Rs gave a harsh ride, but I didn't find that to be the case. I have a B13 sentra se-r with coilovers and the Merc rides like a cloud by comparison. The sportline alignment specs help out a bit as well. I had to use custom camber arms so that we could get the rear alignment in spec. I have the recipe on how to build them cheaply from

The 500e rear bar is definitely tricky to get on. I believe you would have to drop the rear subframe down a bit to get it on no matter what. There was not a lot of room under there with the SLS stuff on my wagon. I had to massage the sls bracketry to work with the bar. The stock rear bar looks like a tooth pick by comparison. Sedans can run r129 rear bars (lots of really big options there) because you don't have the SLS in the way.

I bought new plastic end links to use. I didn't realize the wagon metal ones were sought after, but mine were 20 years old anyway so I figured how good could they really be at this point.

I saw your car has the CLK wheels as well. In my opinion, they are one of the best, functional upgrades for the car. Light weight and much better availability on 205/55/16 tires than the original 15s.

W124_Karl New Reader
1/25/14 9:20 p.m.

That's good to know on the R129 bar option. I hadn't thought of that. But it's a project I'll save for whenever I have to do the subframe bushings. I remember reading about the wagon front bar being the same as a Sportline; wish I'd known it early in my ownership. I picked a '94 wagon over in a self service junkyard a long time ago, but left the bar behind. Oh well.

Incidentally, one of the regulars on is working on a write up of doing his wife's M104 head gasket. He's doing a lot more work than I would choose to do, but it's still instructive. A great read if you haven't seen it yet:

ccrelan Reader
1/25/14 10:07 p.m.

Hi- I have been following Gerry's m104 thread. He has done an amazing job documenting things.

I believe the H&R R129 rear bar is 2mm bigger than the 500e bar. It is definitely easiest to tie in with subframe bush replacement.

chandlerGTi SuperDork
1/26/14 2:57 p.m.

My 300te was one of the best cruising cars I've had, but the 4matic gearing was horrible for taking off from a stop light. I sold it a couple weeks ago and I'm thinking I'll sell my W201 project also, you car is what I would like to emulate though.

ccrelan Reader
1/26/14 3:56 p.m.

Chandler- I saw your f/s thread on the zender 190 on vwvortex. Very cool ride!

The 4 matic cars are not held in very high regard as they are heavy, slow, and not very reliable. With that said, Turbobandit in Sweden has started using the 4 matic cars for better traction. They sell turbo kits that make a ridiculous amount of power.

ccrelan Reader
10/14/14 9:16 p.m.

Over the long weekend, we got around the changing the interior color on the wagon from saddle to black. I picked up of a mint set of OEM 500e recaro seats. 500e seats never were available in saddle so the best route was the change out the entire interior. We just need to get to the door panels this coming weekend.

Over the summer, I had a set of rare 17x7.5 et30 EVO 2 rep wheels redone. I still need to swap out the front spring pads for some shorter ones. The front is about a 1/2" higher than the rear right now. The car is now riding on OEM 500e springs. They are far and away the best option for a w124 wagon. Stiffer than the H&R's that were previously on the car without the slammed front ride height.

Here are some pics:

<img src="wagonevo" />

<img src="500e seats 1" />

<img src="500e seats 2" />

Mezzanine Reader
10/14/14 10:29 p.m.

This is such a great build! I have a '95 E320 sedan, that I just love. I plan to go with a sportline suspension overhaul at some point, but I'm not in any hurry. I have a head gasket job ahead of me too, if the slight scum of oil in the coolant tank is any indicator.

Would you suggest the 500e and wagon sway bars over the sportline bars? This is my wife's DD, but we would both appreciate a little flatter cornering abilities.

ccrelan Reader
10/15/14 5:10 a.m.

Highly recommend 500e rear bar! The sportline front bar is the same exact thing as wagon front bar- no difference.

cdowd HalfDork
10/15/14 10:02 a.m.

nice build. Did I see the edge of a 16v 190 in the picture with the exaust? lets hear about that as well.

ccrelan Reader
10/15/14 5:04 p.m.

Not my 16v. It belongs to the builder of the exhaust.

cdowd HalfDork
10/16/14 8:24 a.m.

My dad bought a 16v new in 87, I loved that car. I really like the interior you are putting your car as well. there is a 280sl on Bring a trailer right now that has a c36 motor and 5speed in it that looks cool as well.

ccrelan Reader
10/16/14 7:19 p.m.

My plans for the car are going to be changing some. I am going to be picking up the engine and transmission from the car in the link.

So, I will not be swapping the wagon to a 5 speed manual. My friend and I are on the fence as to sell the manual swap kit by itself or install it on another w124 with my existing 3.6 and then sell.

The twin turbo motor is going to be amazing. I will have to sort out the Microtech stand alone injection and work on some sort of intercooler set up as the car was not running one. It was using methanol injection for cooling the intake charge. The newer style 5 speed auto is more than up to the task of the power and also has fully programmable TCU.

conesare2seconds HalfDork
10/20/14 8:25 p.m.

Dang. That is one sweet u-boat.

ekstarr New Reader
5/4/15 6:56 p.m.

What an awesome post. Thanks for all the information and visuals.

I have a '95 E320 Wagon with the Sportline upgrade. I LOVE this car and don't want to get rid of it. My mechanic suggested I sell it because there's a decently large list of pending repairs needed (head gasket, motor mounts, an SRS issue, etc). One of which is the head gasket.

I mentioned the idea of the c36 AMG engine swap being plug-and-play. I printed this post. He's very skeptical that it's plug-and-play, thinks the costs are not worth it, and not sure he wants to do the work. I was curious if you had any advice or links to more detailed information on the swap. I've done a bit of research on this, but it seems your post was the most detailed.

Pictures below:

Thank you in advance for your help!

XJguy New Reader
7/30/16 12:08 p.m.

Hi, I'm a bit late to the party. Very interested in what the sway bar situation for these W124.

Has anyone actually installed R129 sway bars onto the W124? My understanding is that it's only the front R129 that can fit the W124, that the rear best option is from a W210 E55?

Oh ccrelan, thanks for the Speed Tuning reference, I contacted them and am going to have my stock computer reflashed for my E320, they said I can expect about 20/20 hp/tq increase....not bad for less than $300.

4/8/19 5:44 p.m.

ccrelan - can you tell me your source for the flywheel, and what clutch kit you used ?



:-) neil


irish44j MegaDork
4/8/19 7:19 p.m.

man, looks great! Seems like a fun sleeper as well. Love me some fast wagons. 

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