Gwagon Speedometer Upgrade

Like many of us, the odometer on the original VDO speedometer was shot. It would sometimes work, sometimes stick and often just sit there. for older cars, this may not be an issue, but I wanted to know simple things like, how far I traveled and when to change the oil. While I was lucky to have an MPH speedo, many of the imported G's from the 80's, feature Kilometer measurements. Here is a quick and easy solution for many of us.

Original VDO Speedometer

For the purest, it would be best to send your speedo off for repair. There are many good resources that repair classic speedometers and the original VDO unit is very nice. In my case, I wanted an upgrade.

A quick search of available VDO gages and you will find nice digital VDO gauge that will fit directly in the existing cluster. I settled on a VDO Vision Black 85 MPH/130 KpH Speedo (12/24V) - 3 3/8" - Vision Black model number 437-152. The bonus is that for those of us who have 24v G's this gauge will work!

For those of you who think a 120 MPH gage is better, think about it for a second. These trucks rarely go over 70 much less 85.

 I ordered the sender and the gauge from eGuages.com. The bonus is the new speedo is only about $130!

Existing Cruise Control Sensor

The old gage worked by a spinning cable that comes from the transfer case to the back of the old speedo. The new unit, however, is 100% electronic. An electronic pulse is required to measure the speed of the car. The speed can be picked up by a pulse coming from any part of the drivetrain after the transmission.

It is very easy to access the cluster. Two screws one on each side then the back cover comes off. Simply unscrew the cable, remove the lights and you push the old speedo out of the front of the cluster. then I took the rubber surround from the old speedo and put it on the new one and slid it in.

The wiring instructions come with the new speedo, the only strange thing is the new speedo does not have a blinker light. That is not a big deal, I just wired the blinker indicator to the one on the sash luster and I was all good.

Then came the hard part. Getting some sort of speed signal to the new speedo. Let's just say I found it impossible to find an adaptor that would fit the pulse generator to the existing speedometer cable or transfer case.  I was lucky because when I followed the old speedometer cable I found an electronic sensor connected to the cable under the dash. At one point my G must have been equipped with cruise control, so I wired the connectors to the new speedometer and while it did not register the correct speed, it did work.

The wiring was pretty simple. as follows:

12V constant to Pin 4
Ground to Pin 3

New Speedometer

Existing Sensor to pins 7 & 8
Dash lights to the Light Sockets

I had replaced my dash lights with LED lamps to I updated the lamps int he speedometer to match the LED color I used the the rest of the gages.

All that was left was to calibrate the speedo. I downloaded Ulysse Speedometer to my smart for reference. Then used the Manual Calibration method to get the speedometer to match the value shown on my phone. The end result was a stock looking electronic speedometer that is reliable and easy to read.

These Go to 24!

In Spinal Tap, Nigel Tufnel is always bragging about his amplifiers "These go to 11!" We all know that the markings on the knob have no effect on the actual ability of the amp to put out high sound pressure levels (SPL) but it does give Nigle bragging rights and maybe helps him feel better on stage.

Some of us with military G's have similar distinctions because the old military G-Wagons were outfitted for radio gear and featured 24V power. Unlike their British cousins that have 24V just for the radio gear and 12V for the truck, the G-Wagons feature a 24V throughout. This means we have 24V starters, blowers, lights, alternators, wipers, and glow plugs. I've owned both 12V and 24V 300GD wagons and while the 24V is kind of a pain to maintain, it does have some advantages.

First let's talk about the challenges.

• If you leave your lights on and the batteries drain, you will need two cars or two batteries to jump-start the truck. (I keep two sets of jumper cables in my car.)
• When replacing the battery, you will need two rather than one.
• Just about every electrical part from the light bulbs to the starter are harder to source and expensive to replace.
• There are a limited number of 24V entertainment options. 
• You will need a to charge your batteries one at a time if using a wall charger. 

Now the advantages.

• The 24V starter seems to be better at turning over the engine. 
• I've always been able to start the car even when it super cold, even when it below zero fahrenheit. Do the glow plugs work better, I'm not sure. 
• I had two batteries wired in parallel with a quick disconnect relay in a 12V 300GD so it always had current to spare, but the dual 12V batteries in the 24V G wired in series seem to perform better. 

The electrical system in the 300GD is very simple. That is why many of us like it so much. Once started, an OM617 engine does not even need electricity to operate. There are no computers, no fancy electronics, and no ignition system. In fact, a vacuum system is used to turn the engine off. So having a 24V 300GD is really not a big issue. You would think that having a 24V car and getting accessories is a big deal, but when you think of all the 24V tractors and trucks on the market, it is really not that big of a deal.

Need a 24V phone charger? No problem. Need a radio? Simply get a 24V tractor radio. There are even options with Bluetooth and USB interfaces. Want to upgrade to LED headlights? Many LED kits support 24V. Here are some resources to help.

Dash Lights

Dash lights seem to go out on just about every G-Wagon. While I have not been able to find a good 24V LED replacement, I was able to find 3rd party replacements. CCIYU T5 LED Bulbs come in three colors red, green, and LED blue, and fit right into the back of any of the instruments for illumination or indicators on your G. They are a great value and look better than the factory originals. 

24V Tunes

A lot of tractors have 24v systems so there are some tractor options, but I found an even better solution. VDO actually makes a great-looking Radio, with USB, Bluetooth, USB MP3 and it is 24V. Just do an online search for the VDO TR723UB-BU, It can be easily wired to come on when you turn on your truck, and even has illumination that works with your dash lights. It features some EQ options nas a nice display and has 4x15W output so it has plenty of power. The best part is the guages in the G-Wagons are VDO so it matches. 

LED Headlights

Simply look for any H4 headlight that supports 24V. I found the Gppower 80w 6400LM car Cree Led Headlights bulbs 12-24V and they work great. They are not any brighter than 12V LED options but they are WAY better than the standard halogen bulbs and use a LOT less current. 

I've heard some 24V G owners converting their trucks back to 12V. It would not be that difficult but after owning a 24V version, I would say the advantages are way better than the inconveniences. Sure you can probably update the entire truck to 12V for the price of a 24V alternator and heater blower, I'll keep mine at 24V thank you. Because while my 24V 300GD does not run any faster than a standard 12V version, Like Nigel, I do feel superior to everyone else because let's face it, "This One Goes to 24!"

My Other Car is a G-Wagon

The 300GD is a great car to drive around town, and even better when there is a need to check out the back country here at Rocky Point Preserve, but for a trip down to the valley or a longer road trip, the OM617 can be a little loud, cold and underpowered.

I just can't get a new car and was in need of something that can get back to the preserve up Tollgate Canyon in the winter. For a while I was driving a Jeep Wrangler, but it just did not feel right. Years ago I owned a Jeep Cherokee, the old XJ version that was made from 1984-2001. It was the first Jeep to feature unibody construction and had the most awesome 4.0L fuel injected inline 6. In my mind, the early Jeep Cherokee bridged the gap between the G-Wagon and other early capable 4x4s and the new breed of family SUVs. The thing is, the Jeep XJ still has the drivetrain, engine and capabilities of a great 4x4.

According the the Wikipedia entry:

Automotive journalist Robert Cumberford, writing for Automobile, called the Jeep XJ one of the 20 greatest cars of all time — for its design, and "possibly the best SUV shape of all time, it is the paradigmatic model to which other designers have since aspired". The XJ was also selected in 2011 as one of "10 cars that refuse to die" by Kiplinger.

Since so many were produced and because of reliability of the 4.0L engine, there are a bunch of these around and they can be had for such a low price that many feel them to be a disposable 4x4. I decided to start looking for one to be my next 4x4 project car. I was lucky enough to find a 2001 accident free automatic with just over 100K miles that drove well but needed some TLC. $2500 and I had my next Jeep XJ.

First I gave it a quick 3" lift, replace all the springs, put in new bushings, new steering damper, had all the fluids flushed and replaced, replaced the failed thermostat, breaks and replaced the radiator and hoses. The car ran pretty good but it looked like hell. There was surface rust and the interior was in pretty bad shape. Once the mechanicals were sorted out, it was time to focus on the body.

I decided to try out the newest local body shop Cascade Collision and started to come up with a plan. We would sand blast the car, cover it with epoxy, get it straight, prime it and repaint it... YELLOW. I took the car home to remove the interior and get it ready for the shop. The one thing I was most worried about were the floor pans. But GREAT NEWS, there was absolutely no signs of rust under the carpet or anywhere on the interior.

Once back at the body shop and sand blasted a quick look over showed just a couple of minor spots that needed attention. The body was very serviceable.  The guys at the shop quickly started pulling the car apart and working on the body, replacing the front door hinges and getting it ready for primer.

It took the shop almost 3 months because winter is fender bender season and the shop got very busy, but finally we got some color on the car and it looks great.

Pulling apart the car for painting allowed us to make sure it would look more like a full restoration rather than a respray. Once the car is together, it will be very difficult to figure out the car was ever blue. More importantly, there will be almost no place water and salt can penetrate and cause rust. 

While at the shop, I had cascade assemble and install the Smittybilt XRC front and rear bumpers, the rock sliders and application of the black matching coating along the bottom of the body.

Once I picked up the car, it was time to rebuild the interior. Over the next two weeks I installed new carpeting, seats, dynaliner, stereo, speakers and headlights. I worked with my little guy, Delynger to get the winch installed and add a bull bar. I also ordered new wheels and worked with Discount Tire to fit serious all terrain tires. I also added a new larger throttle body, throttle spacer and Airaid filter system. I feel like I'm getting about 10% more HP out of the 4.0 L inline 6.

Now my "Yellow Jacket" is mostly complete (are they ever really complete?), it is be ready for a sticker on the bumper... "My Other Car is a G-Wagon"

2001 Jeep Cherokee XJ At Rocky Point Preserve, Park City UT

OM617 - Every Engine Needs This

Readers to this blog know that I have had a couple of OM617 engines both turbo and naturally aspirated. I love these engines! While they don't put out much in the way of power, they are extremely reliable, easy to work on and virtually bullet proof.

If you have one, here are four simple things you should do:

1. Keep the fuel filters clean. 

When I got "The Turtle" it was way underpowered and seemed to lose power on even the smallest hill. This is common for the little 3L diesel, but it just felt starved. Replacing both the primary and main fuel filters was an instant cure. Remember older cars may have small flakes of stuff in the fuel tank so changing at least the primary filter often is a good idea. This is easy to do and does not cost much.

2. Clean Prechambers

Prechamber Reamer

Removing the glow plugs and reaming the prechambers is kind of a pain, but a couple hours under the hood and you will see a huge performance in cold starts and much smoother running engine.

3. Adjust those Valves

These engines don't self-adjust like newer engines do. I've gotten into the habit of taking my trucks into a good independent local Mercedes shop and having them adjust the valves couple of years. You could do it yourself but my shop does not charge that much. The engine sounds better, starts better, runs smoother and gets better gas mileage.

4. Diesel Purge

Running some diesel purge through your engine, especially high mileage ones, will clean that carbon from the fuel system, help keep the prechambers clean and restore performance. When you first get your OM617 powered car, run two cans through it and do a single can purge again every year thereafter. Remember to change your fuel filter after the purge. There will be TONS of gunk freed up during the process. CLICK HERE for detailed instructions on how to diesel purge an OM617.

5. ALDA on the OM617a Turbo

If you have an OM617, make sure the ALDA is clean and working. You can even look at doing an adjustment. CLICK HERE for instructions and more info.

I bet the previous owners of the trucks I've purchased would have never sold them if they performed these simple four steps on their OM617 power plants. Together, these simple maintenance tips will make you fall in love with your 300 again. 

The Turtle - W641 Puch 300GD

I had to sell the W460 featured in this blog because I had too many cars here and needed some quick cash. I listed it for what I considered a fair price with 3 other cars and got a ton of calls for the 300GD - the other cars, not so much. Short story, in 24 hours the 300GD Turbo was sold.

I missed driving my 300GD Turbo SWB so much that it was not long before the bug hit me, and I started looking online, not really to buy but just to look and see what was out there. After a while, I thought it would be cool to find a mid-1990's example and transplant an OM 606.964 ERE or OM 606.962 ERE 6 cylinder turbocharged diesel with a 5-speed. That sounds cool, right?

Just for fun I started going out and test driving some G-Wagons for sale. Not that I was going to buy anything but just to do research for a future purchase. I drove a 1991 300E, a 2005 Supercharged G500 AMG and a few other less memorable G-Wagons. By the way, the supercharged AMG is sick fast. Something just felt wrong going 0-60 in 5.4 seconds in something that felt like a tank. The 300GE was surprisingly quick and responsive. Fun times!

Then it happened, somebody drove a 1990 W461, Puch Austrian Military 300GD into town and was selling it. The owner was on vacation, but with the owner's permission my friend and I drove over to look it over.

The truck was soo cool. It was a 300GD, LWB, Cabrio, 4-speed manual with a naturally aspirated OM614. On top of that, it had jump seats for eight bringing the total to 10 passengers including the driver! We tried to start it but it was DEAD! The issue was the 24v electrical system could not be simply jump-started with one car.

We decided to drive our Jeeps over and use two cars to jump-start the beast. It cranked up and was very rough. My immediate thinking was it needed glow plug work or the diesel pre-chambers had carbon build up because after it warmed up, it drove pretty well.

The front end exhibited no noise, there were a few small rust bubbles at the bottom of the wheel wells and on the windshield, an engine oil leak, and seepage from the front differential and the transfer case. All pretty normal stuff. The soft top was in pretty good shape, some clouding, and one cracked window but all was very serviceable. The front headlights and the heater blower did not work.

So in a moment of weakness, I made an offer and bought it. The engine leak turned out to be a loose oil drain plug, a quick reaming of the prechambers and diesel purge solved the rough start issue. Headlights turned out to be blown low beam bulbs and as it turns out it even holds a charge. This could be a daily driver!

My current plans are to give it a good once over mechanically and have the minor rust issues resolved before they get out of control. Driving it around I get a lot of: "What is that?" and "Where did you get that?" and "Can I get a photo?" I have not decided what to do long-term, but you will hear about it here. How does it drive? Well.. lets just say it is a lot more spartan and just bit slower than the 2005 AMG! Can you say "Ari Safari?"

Fuel Tank Repair or Replace?

I noticed some fluid from the back of my car in late August of 2015. A quick whiff and I discovered it was diesel fuel. DANG! This is the summer of front-end repair, a new starter, and now a leak in my fuel line.

A few days later I decided to take a quick look and the fuel was leaking from where the folks who did the conversion from gas to diesel took the fuel pump out. There was an extra filter and an adaptor. EASY - WRONG! It looked like the fuel was coming from the top of the tank and dripping down. It could be the rubber hose but I decided to remove the tank and make sure.

Here is what I did:

1. Run my truck to almost empty.
2. Disconnect my battery (no power, no sparks, no boom)
3. Removed the rear mat to get to the floor.
   
4. Removed the four philips screws that go to the square panel in the middle and remove the plate. 
5. You will see a plug with three wires going to the tank, remove the plug. (If you like you can remove this unit and pump your fuel out at this point)
6. Also, remove the breather hose that goes to the top of the tank.
7. My truck features the extra two tanks in the side pillars so I jacked up the car, removed the clamps from the large hose that goes to the lower tank and disconnected the hoses. You will need to squeeze them to get them off. Then lower the car back down. 
8. Then I removed the lower hose that feeds the fuel system and drained the tank into a diesel container. (Note this will not remove all the fuel)
9. I then removed the return fuel line at the top of the tank.
10. I then placed a hydraulic jack under the skid pan and jacked it up just enough to hold the tank in place. 
11. Two metal straps are all that hold the tank, so simply remove the 13mm nuts and remove the straps. 
12. Now slowly lower your jack and the tank will start coming out back first. Watch out not to spill the remaining gallon of fuel.

Rust on Bottom of Old Tank

With the tank out, I noticed the skid plate for the fuel tank was rusted BAD and had started to cause pitting on the bottom of the tank. I did not see any leaks on the tank but did notice a previous patch on the left side. I also noticed where the tank had been dented on each side probably from some serious off-road use!

The skid plate was going to need to be replaced, the tank replaced or at least reconditioned and I would upgrade all the small rubber fuel hoses. Now the fun.

If you have an early model G-Wagon you probably know about the plastic tank conversion. Quick summary: for about $1200 you can purchase a new plastic tank and for $1800 more the kit to install it. The upgrade is a good idea because plastic is better than metal for a BUNCH of reasons. Before we talk about what I decided to do, let me give you some important HARD TO FIND info that will save you money and time.

Original Tank From top back

• The Mercedes part number for the new Plastic Tank for the W460 and W463 is A4604701201.
• The Mercedes part number for the installation kit is A4614700004.
• You can get an after-market part for a LOT LESS from a parts supplier in Latvia at: https://plasticautotank.com/ € 539.25 for the tank and does not require a kit. Even with freight of €599.00, it is half of what they sell for in the States!

New Plastic Tank A4614700004

I'm keeping my car so I considered ordering the kit and the tank. Delivered it would still be $1500, but that would mean I could only use one of the extra tanks fitted on my car. The one on the driver's side would not be able to be used. I would have a nice new tank, new fuel sensor, new tubes, new, skid plate and new straps. Pretty much guarantees no more fuel problems for me and my G-Wagon. But I decided to keep looking.

I've got a couple of classic cars and decided to look at fixing the tank and maybe getting a new plate made. I know fellow car enthusiasts who have had major tank work and they look great and work for years.

The folks I found locally (State Automotive) use a process called Renu. The tank is cut open, sandblasted inside and out, holes repaired, and sealed with special Renu coatings. They look great and are sealed in a way where they will virtually never rust. The entire process cost just over $500 and in two weeks I had a virtually new tank.

Reconditioned Fuel Tank

They pulled out all the dents and with the new finish the tank was tough and solid. Actually, I think it is now better than new and should resist all corrosion. They even said there was a lifetime warranty for as long as I owned the car. The best part, it was an exact fit.

I purchased all new hoses, new clamps and sanded down the straps and applied primer and three coats of paint so the straps would look as good as the tank. I installed the tank without the old rusted skid plate for now and it looks and works great. 

If you are doing this yourself, make sure you keep the inside of the tank clean, don't get the supply and return on your diesel lines reversed and make sure all hoses are well clamped to eliminate the risk of any air getting into the fuel lines. Once installed you may need to use your diesel primer pump to prime the fuel system. 

One more thing to check: After the installation of the new tank, my return lines were seeping at the joints and I was getting a lot of black smoke. I pulled off the return line from the engine and applied some pressure and found the fuel was not going anywhere. The return line was clogged and since the seeping was all the way at the tank, it had to be in the tank. I ran the tank to almost empty, removed the line going to the tank and used a thin flexible wire brush to clear the line. When I first inserted the brush, there was a lot of blockage, but with a little pressure, I was able to clear the line. The car instantly ran better and all of the seeping stopped. 

With the tank reconditioned and installed, it was time to start thinking about the skid plate that covers the bottom of the fuel tank. The skid plate for the metal fuel tank and the plastic tank are different and don't look to be interchangeable. Four by Four Club is the only place I found the old-style plate and it is expensive, like $550. CLICK HERE for the plate for the gas version I believe it will work for the diesel as well, but a quick call to Vlad will verify if it works for the diesel tank. ORC also makes aluminum front and back skid plates for the W460 and W463 G-Wagons but they are designed to work for the new plastic tanks as well. 

I decided to visit a local sheet metal shop, Sheet Metal Fabricators, and see what they could do. Showing them the rusted rear skid plate they said they could fabricate one for less than $400. He could not reproduce the grooves but otherwise, it would work perfectly. I asked if they could make it from aluminum and they said it would not cost much more. Lead time: two months. When complete, I'll have it powder-coated red just for fun and it will be as nice as the ORC versions. 

Stand by for results.    

  

Whining Front-End

I don't do a lot of highway driving, and since it is pretty cool, almost never with the windows down. But early in the summer of 2015, I was on a classic auto excursion with a friend looking at T-Birds and noticed that when I was driving along a wall, there was a horrible metal on metal scraping sound from the front end of the car. NOT GOOD! When I got home I started looking at the front end. 

I jacked up the car and sure enough turning the wheels gave that scraping sound. I ordered the Front Axle Service Kit from Euro Truck. I took the truck to two independent shops with the instructions and neither wanted to do the rebuild. I finally gave up and took it to my local Mercedes-Benz Dealer in Salt Lake City and the service manager said they could do it!. I knew it would cost more, but I was ready to get this fixed. 

The next day the service manager at the Dealer said they could not fix it because of pitting on the large steering balls, it would just not work. They offered to sell me a new axle for $12,000. Right! I picked up my car. 

I asked around and found a shop called Gears Transmission and Drivetrain Repair that specializes in 4x4 repairs. I called and they sounded confident they could do the work. 

I dropped off the truck and the rebuild kit and they called the next day. There was excessive wear on the right axle and al little less on the right. OK, no problem, let me get the part. 

I called Sean at Eurotruck and he said it was not something he usually has, but he would make some calls. A week later he said there were none to be found, but Mercedes would call the factory that made them and have some made. They would be about $1100 each. I'm planning to keep the truck so I ordered them. Now Sean carries the parts and you can see them HERE.  

About a month later they came in and a week later the folks at Gears had my truck ready. The labor was about $1300. So for about $4000 total I got new axel shafts, differential cover, pinion seal, boots, CV joints, bushings, wheel bearings, kingpin, kingpin seal, steering ball seals and gaskets. It sounds a LOT better and runs much smoother. Also fixed is the seeping of differential fluid from the wheels near the steering balls. There is still a little sound from the differential but that will have to wait for another day. 

Now when folks ask me about maintenance of my super cool car I say, "Most repairs are pretty easy and inexpensive, Except the front end!"  

G-Wagon LED Headlights

The original headlights in the 80's era G-Wagons are pretty pitiful by today's standards. The best headlight technology of the time was halogen bulbs. Don't get me wrong, I am old enough to remember the old incandescent sealed beam headlights and the halogen bulbs were a huge improvement. It is just today we have HID and LED. 

HID was go to lighting system for luxury cars until recently. LED has taken over. 

High Intensity Discharge or HID are those bulbs that take a while to reach full power. They use an arc to excite an inert gas to make light. They are a huge improvement over Halogen because they are more efficient and produce whiter light but over time they tend to change color and loose some of their intensity. 

Light Emitting Diode or LED lights have been around since the 80's but only recent advancements have allowed them to be used as a light source. The are available in a wide spectrum of colors (see what I did there?), use less power and last longer than HID, halogen or incandescent systems. 

HID systems are effective, can be expensive but the biggest issues is they are complicated to retrofit into the G-Wagon. I got an HID kit and sent it back after reading the instructions and I majored in electrical engineering. So I started to consider LED as an option. Most folks think that if you want LED headlights you will need to replace the entire assembly. I tired one, it was expensive, did not look that great and was not all that bright. BUT THERE IS A BETTER WAY!


It took some time but I found a bulb that can replace the standard halogen bulb in the existing housing. It requires no special electrical knowledge and is basically plug and play. Or rather plug and drive. There are several out there, but I choose the GP Power 6400LM kit. As of press time they are less than $30.00 on Amazon.

If you are an owner of a military version of the G like a Puch or Wolf, then make sure you use a LED solution that supports 24V. Some LED solutions support a range of power from 8V to 27V. I' can confirm the GP Solutions 6400LM does work on a Puch 300GD at 24V.

If you know how to change bulbs just stop reading, order them and install them. They pretty much just fit. If not, read on...

First removed the rubber or plastic bezel around the lights. Just unscrew the single set screw at the bottom, gently pull the bezel out at the bottom and slide up. It will just come off. Once removed, you will see a metal ring holding the light in place. There are 6 screws on the ring three hold it in place and three are for adjusting the light. Remove the three screws indicated by the arrows.  

Careful the light will come out toward you. Unplug the socket from the back and if you are lucky enough to have the EURO version unplug the parking T10 light at the bottom. If you have a sealed beam headlight, you are screwed. You will need to upgrade to a Hella 002395991 7" H4 Light  a removable bulb.

Take the housing over to a workbench or table. Remove the rubber trim from the back to reveal the spring loaded wires that hold the H4 halogen bulb into place. Push the pins down and squeeze them together so they come up and hinge back out of the way. Then simply remove the H4 bulb.

Now take one of the LED bulbs and install it into the housing. The bulb will only fit one way, make sure to line up the three tabs properly. The fit is TIGHT so take your time and gently pry the metal housing out if necessary. You may want to put a little silicon bead on the housing prior to installing the light to keep water out.

Once installed the housing with the new LED H4 headlight will look something like this. NOTE: Don't try and install the rubber water guard you removed above. 

You may want to take this opportunity to replace the parking light with a T10 LED so it will have the same color. Once complete take the new headlight back to the car and install it in the housing. Make sure the headlight fits into the three tabs on the housing. Put the ring around the light (the DOT stamp goes on top) and install the three screws. Test your lights before putting the black trim back on. Adjust the beam using the other screws around the headlight as necessary, mine had to come down a bit. 

Once complete, they worked perfectly with a slightly wider pattern on low beam, whiter light, more distance on high beam. One bonus, on high beam the low beam lights still work. They are so intense, you may find you no longer need the fog lights. All this for about $30 and 20 minutes of time. 

The Fifteen Dollar Diesel Tune-up

With over 150,000 miles on the 30 year old OM617A turbo diesel, there has to be some build up in the fuel system. Many Mercedes diesel owners have spent countless days tweaking the performance of their engines and many talk about the benefits of a diesel flush. It looked easy and inexpensive (two of my favorite things) so thought I would give it a try. The entire process took less than an hour, gave me more power, smoother running engine, less valve noise and a more responsive engine. 

Some folks advocate removing the injectors and cleaning or replacing them rather than the Diesel Purge. Here is my thinking: The purge will not fix a clogged injector, nor will it clean as well as removing them and cleaning them. But even if you do clean or replace the injectors, there is still carbon build up in the prechambers and fuel delivery system. This will clear the ENTIRE fuel system and unless you are doing a rebuild, a diesel purge is a great option. 

The product I used is called Liqui Moly Diesel Purge available from just about auto shop or you can order it from Amazon for about $15 and easy to find for even less. If you are comfortable under the hood and understand fuel systems, skip the rest of this blog and follow the instructions in the video to your right. Warning it is a little bit of an ad, but does provide good information. 

If your under the hood skills are limited to checking and topping off the oil, I've got step by step instructions that will work on just about any diesel engine. I'm using the OM617A that is in my 300GD for an example. 

A little background first. The diesel fuel is pumped from your tank, through a filter (maybe 2), through a throttle that modulates the amount of fuel, then eventually to the injectors that feed it into each cylinder. Now the injectors can't use all the fuel so some is fed back into the fuel tank. So the entire system is kind of like a loop with the engine sipping off what it needs. 

OM617 Fuel Lines

Here is a quick summary of what we will be doing:

1. Disconnect the fuel line going into the filter - this is where the Diesel Purge needs to go into the system.
2. Disconnect the fuel return line going back to the tank - this will need to be fed back into the Diesel Purge bottle. 
3. Take the line you disconnected in step one (the one that came from the tank and fed into the filter) and plug it into the line going back to the fuel tank. This will keep the lines from getting air and the pump from spilling fuel all over the place while you purge the system. 

Before you begin you will need:

1. A can or two of Diesel Purge
2. A 10" tube of rubber fuel line hose
3. A clear plastic bottle - large enough to hold all the product.

NOTE: During the process you don't what to run the engine while there is no fuel going into the system or you will need to prime the fuel system to get the air out. 

I also suggest warming up the engine before starting this process. Things just seem to clean better when they are warm, right? 

When disconnecting the fuel lines you will have to loosen the clamps with a screw driver or clamp remover. No need to tighten them during the purge but remember to tighten them back up when you put everything back together. 

Lets start by removing the line coming back from the injectors. In the OM617 the return line comes from the injector closest to the front of the engine and runs to the top of the filter. From there it feeds back to the tank. Remove the hose that feeds the tube going to the tank so that you have about a foot or so of hose hanging loose. I like to point the hose up to reduce the amount of fuel that will leak out.  

Return Fuel Line Removed

Then disconnect the line going into the primary filter. This line is coming from the fuel tank and supplies the diesel fuel to the system. If this primary filter is not present you should install one. In cold climates, this filter will become clogged first when it gets cold with the waxy diesel and is easy to change. 

Primary Fuel Filter Line

Then connect it to the return line going back to the tank. You will still have the return line you disconnected before sticking up in the air. This is important because when you start the engine a fuel pump will pump fuel from the tank. By hooking it back to the return, it will simply be pumped back into the tank and not spill all over your garage.

You can feed those tubes directly into the can of Diesel Purge but the metal bottle makes it hard to see how much purge is left. By using a clear bottle or glass jar, you can see how much purge is left and cur off the engine prior to in running out. This keeps air out of the system.  

If you use a plastic water bottle, make sure is is DRY and clean. Then cut a hole in the top and feed the return line coming from the injectors into the bottle. Then take the 10" extra fuel line you purchased and connect to the small filter to supply the engine. Make sure the second line going to the filter stays submerged and rests in the bottom of the bottle. The return does not need to be inserted to far into the bottle. Wedge the bottle in a safe place so it stands up. 

Once everything is hooked up, turn on the engine and let it idle for a while. Once you are sure it is working, increase the throttle from under the hood and run the purge through the system at a verity of RPMs. If you are using a clear bottle, you may notice it getting a little dirty. That is the carbon build being removed up BEFORE the injectors, just think of what is being cleaned from the injectors and the pre-chamber!

Purge System in Place

As the bottle becomes empty, shut off the engine remove the return tube and use a funnel fill the bottle with more purge. If you have not done this before, use two full bottles of product. The entire process takes about 10 minutes per bottle. 

Remember to stop the process before the product runs out. I play it safe and shut off the engine with about a 1/4 inch of purge left in the bottle. 

When you are done, reconnect all the fuel lines as they were connected before and test you engine. It is a good idea to change at least the primary fuel filter now as it will have collected some carbon residue. Go for a test drive now and you will notice less smoke, smoother running engine, more power better cold starts and a quieter idling engine. All of this for $15 and about an hour of shop work.  

As you can see this process is pretty easy. I'm planning on doing this about every 12 or 18 months just to keep the engine in good shape. 

Mercedes Transmission Experts - Sun Valley Mercedes Transmissions

When I purchased my G-Wagon, it came with a large cache of documents detailing the service history of the vehicle. Included was a December 2008 invoice for a rebuilt transmission from Sun Valley Mercedes Transmissions. When I started having transmission issues, I looked the shop up on the internet, found the web site and was not very impressed. After exhaustive troubleshooting and help from a local shop I came to the conclusion that the transmission needed work. Before having it rebuilt locally I decided, at the last minute, to reach out to Sun Valley and get their take on the situation. 

Sun Valley Mercedes Transmissions

I'm glad I did.

Sun Valley Mercedes Transmissions is located not far from where my daughter Ally works. All they do is rebuild Mercedes transmissions. After a short call with Marc, I decided it would be best to have the transmission pulled and take it to them on my next trip to visit Ally in LA.

When I arrived I was impressed. First of all, I was surprised to see the shop was next door to the famed Sound City recording studio where Fleetwood Mac, Tom Petty and Nirvana all recorded. That studio really is the source of the best sounding drum recordings from the 70's, 80's and 90's. After the shock of standing next to the legendary studio passed, I was given a tour of the facility by Marc. 

I was impressed with what I saw. Inside was an efficient, well stocked and organized environment filled with just about any Mercedes-Benz automatic transmission you could imagine. From the first units made in the late 60's to the modern 7-speed computer controlled systems. It was great to find a specialist that ONLY works on Mercedes-Benz transmissions. 

Marc showed me how they disassemble each transmission, check the components, machine and replace as necessary, upgrade when needed, reassemble and test. The shop even has the ability to program the newer 7-speed computer controlled transmission computers. I was beginning to think the transmission would actually be better after the rebuild than when it left the factory!

Mercedes-Benz Transmission Testing Rig

After the work is done, they have two in-house made systems where they mount the transmission for testing. Each features a different Mercedes-Benz engine. One of the rigs had an OM617 Turbo - just like the one in my G-Wagon. BONUS!

While they can sell transmissions with a core replacement, Marc told me he prefers to rebuild your transmission. After the tour, I felt very comfortable leaving my transmission with Marc and his team for repair. He said it would be ready in about 3 days AND IT WAS!

Even though the transmission was 5 years out of warranty, Marc and his team fixed it at a substantial discount. I came away very happy with the experience and confident I was not going to have trouble with this transmission again. 

If you are in Southern California and need transmission work done on your Mercedes-Benz, this is the place. If you live outside the SoCal area, give Marc a call and consider sending him your transmission for a rebuild. They are fast, affordable and from what I can see do excellent work. Don't let the crummy web site fool you, these guys are experts. 

While you are there, take some time to take in Sound City vibe. Soundtrack: Reannan, Free Falling, Smells Like Teen Spirit...