I have a 2002 C240 and I changed the engine oil the other day, we are at 114,000 miles btw, and noticed some engine oil on the underside of the front of the transmission. I also found some in the rear underside engine/tranny cover.

I have some pictures to look at here.

Any idea or known problems what this could be? I am assuiming it is engine oil becuase it was not transmission fluid (at least it was dark and not red). Hopefully, this isn't the torque convertor taking a dump.

Check out the pictures here www.installuniversity.com/mbproblem/

Thanks in Advance!!

Eric
www.installuniversity.com/mb

 

More likely than not, what you're seeing is transmission fluid. The MB fluid that comes from the factory is more of a yellowish color resembling engine oil. The good news is that you are probably due to change the fluid anyway after 114k miles. I have a 2001 E320 which, iirc, has the same if not a similar transmission to what you have. Initially I thought the transmission gasket was leaking from the front, because I saw fluid seeping down from the front of the pan, like in your pic. I bought a new tranny filter, gasket and fluid, dropped the pan, changed the filter and replaced the gasket. A couple days later I checked and noticed it was still leaking, except this time I saw the leak only along the passenger side of the pan (like you have in IMG_1162.jpg). Frankly that was annoying because those were the torx bolts *I* had done, while my friend had done the driver side. I'd assumed I didn't tighten the bolts properly or misaligned something. dropped the pan and repositioned and retightened. 2 days later I still notice the same leak along the passenger side pan. At this point I became concerned and spoke to the shop foreman at MB of Georgetown, who pointed me in the right direction.

There is a spacer where a wire plugs into the transmission behind what I assume is a heatshield on the passenger side of the transmission (see your pic, img_1165). I would drop the pan so you can take advantage of this time to change your tranny filter and fluid as well, and get the pesky heatshield out of the way. this is also a good opportunity to clean the torx bolts on your tranny pan of all the accumulated oil and road grime.

Once you've removed the metal shield, you can get to the wire. If I recall correctly, I had to use a screwdriver initially to get the cap off the connection to where the part is. unplug the sensor and you'll be left with just the spacer plugged into the transmission. Deep inside the spacer is a captive hex bolt you'll loosen with a socket (can't remember what size. You can figure it out from the replacement you'll buy). Once you loosened the bolt, you'll be ready to pull the spacer out.

At the top of the spacer there is a plastic flag sticking out from the ring. turn the ring towards the passenger side of the car (I think) and the spacer will slowly unseat itself from the transmission. Once you've rotated it about a quarter revolution, it should be ready to come out. Pull it out and put in the new one, making sure the rubber (silicone?) rings are correctly in place on the new one. Put everything back together (I torqued my tranny bolts at 8 or 12 lbs, iirc). You should have no more leak.

The MB part number for the spacer you'll need is A 203 540 00 53. It cost me $6.00 at MB of Georgetown.

The reason for the leak is the o-rings around the spacer start to degrade and slowly leak fluid out. movement and road conditions whip it around so it looks like the whole front of the tranny is leaking, but you'll see most of the leaking whipping down the passenger side of the pan.

Good luck!

 

This is OT, but for reference, here are a couple of pics from when I changed my tranny fluid. One is the inside of my transmission filter,the other is new vs. old fluid. the old fluid has approximately 85000 miles and 4 years on it.

 

Yep, that is exactly what my fluid looks like. Thank you for your help. But here is another question I really couldn't get a good answer for a while back here.

My dealer says the transmission are sealed for life and there is no need for a filter/fluid change. What say you?

I call B.S. on that but the concesous here was the dealer is right.

 

well, I don't want to get into a deep debate on it or pick any fights, but the idea that a lubricating fluid will last forever sounds a bit silly to me. I tend to think of lifetime fluid as "lifetime that the manufacturer needs to worry about the part". After the end of a 100k starmark warranty, Mercedes doesn't need to care about the state of the fluid. If nothing else, changing the fluid gives you peace of mind (plus, if it never needs to be changed, why is there a convenient drain plug you can open with an alan wrench? see your pic, img_1162 at the back of the pan on the driver's side). Unfortunately, I had to go the dilution route to change my fliud. I don't know, but you probably would have to as well. the drain plug of the torque converter on my transmission was removed as a cost saving measure starting in 99.

 

factory says lifetime fluid. not that we have seen it in print, but there is just no recommended service intervals. our dealer recommends 100k miles max. the techs that drive Benz's like myself agree that 50k is better for longevity esp if you have a later version torque converter with no drain plug. that means just a pan and filter change will yield about a 3.5-4.0l fluid change.

 

Lifetime means the life of the unit. Life can be extended by changing oil an filter.

With the leak buy an aerols degreaser, spray on, hose off and then you will see after a drive exactly where it is coming from.

Bazzle

 

I have the same problem when I tool my C240 for my 3rd Service ( A service)

See my forum posting copy below:-

C240 Auto 2001 - Oil leak in Rear Axle

--------------------------------------------------------------------------------

I own a Mercedes C240 Automatic year 2001 since new. I yesterday took it for A Service ( 3rd since new) . Mileage on clock is 18000. When an MOT test ( Annual Govt. Inspection) was done 4 months ago in September 2005, I was told of oil leak in rear axel. Now I have been told following needs to be done:-

Cost Item Repair description

£180 ( 1) Spark Plug Replace
£75 (2) Main Fuel Filter Replace
£45 (3) Air Filter Clean replace filter insert if necessary
£38 (4) Pilot Bushing on the Electrohydraulic control unit Remove/Install/Seal, Replace If necessary (after check)
£150 (5) Oil pan on Automatic Transmission Remove/Install/Seal, Replace if necessary
£100 ( 6) Bearing (All) for Stabilizer Bar on 1st vehicle Axle Remove/Install/Seal, Replace if necessary
£70 (7) Link Rods (Both) for Front Stabilizer Bar Replace
£30 (8) Wheel Bearing End Float on Front Wheel Hubs Check and Adjust (with wheels removed) This was already done once on B Service in September 2004!
£50 (9) Cover On Rear Final drive Unit Remove / Install, Seal ( Rear Final-Drive Unit Removed)
£270 (10) Rear Final Drive Unit Remove/Install
£30 (11) Road wheels (2) Remove /Install

The total cost of the above is £1152 equal to US $ 2000

When asked how this has happened they did not give me any specific reason. Considering I do very little mileage over 4 years and only 4000 miles since last Major B service 14 months ago, I am wondering why so many things could have gone wrong? What is the main reason for Oil leak in rear axle?

Please advice. I am based in London, UK and we have independent consumer watchdog, which has done undercover checks on many garages and found that many of them where charging for unnecessary/unwarranted repairs which were not required.
Whenever I take the car for service I dread the thought of they coming up with something or other to be done to make some extra money, particularly if you did not buy the car from UK dealer and imported from Europe. The list price of the car including option was £30000 and by importing I saved £5000. Compared to USA we get charged probably 50% more in UK

There is a oil leak in rear axle and front translission box. I took it to an Independent Merc Garage ( Not a MB dealer) . The chap ( Ex head tech of MB) told me that (for the rear axle) this is normal as now a days, merc builds car with soft alluminum and not steel as it used to and because of bumps etc joints get slightly loose and leak. and looking at the leak which is not dripping at all ( I do not see oil spill on my driveway for the rear or front leak) As far as front transmission leak is concerned he told me to get it done because of electronics involved otherwise it could cost £4000 later on.

The part which have been listed for replacement are as under:-

Rods 2
Bush 2
Boot 4
Bracket 2
Spacer 1
Gasket 1
oil 2 ltr
Sealant

If this helps.

Today I am going to take it to a BOSCH service centre to get another opinion and also take to another MB dealer for second estimate by just saying I have a oil leak whcih I was told by a tyre garage when I wanted to have my tyres checked. Now with some rouge garages even they coul dbe MB, what stops then putting some oil on your rear axle and front axel and then say you have a leak? Particularly lay man and rich guys do not care they will just say OK get it done.

 

Hi Wizkid

Can you tell me the outcome of your problem and how much did it cost?

 

I did nothing. I have ordered an automotive lift and I will get the filter and fluid changed and documented as soon as I get my lift in (5 - 6 weeks allegedly).

 

£180 ( 1) Spark Plug Replace

I thought they were 100,000 mile plugs. ?


£75 (2) Main Fuel Filter Replace

I would replace this at 50,000 miles or if you have had bad fuel

£45 (3) Air Filter Clean replace filter insert if necessary

Mine is a recommend change at 70,000 miles but I replaced at 50,000

£38 (4) Pilot Bushing on the Electrohydraulic control unit Remove/Install/Seal, Replace If necessary (after check)

What is an Electrohydraulic control unit. ? Brakes SBC tranny? Could you state in english what this is and does.


£150 (5) Oil pan on Automatic Transmission Remove/Install/Seal, Replace if necessary

WHY is it leaking. are you changing the fluid. If so replace the gasket and filter. I would do this at 50,000 to 75,000 miled depending on driving conditions. My owners manual reco's no change but I will still change before 75,000

£100 ( 6) Bearing (All) for Stabilizer Bar on 1st vehicle Axle Remove/Install/Seal, Replace if necessary

Why Is this defective? Or is this the rear wheel bearing leaking oil from the seal. The information is not clear.

£70 (7) Link Rods (Both) for Front Stabilizer Bar Replace

I have only replaced these on my Corvette when I tore the boot with a screwdriver working in the area. Otherwise they were good for well over 100000 miles.

£30 (8) Wheel Bearing End Float on Front Wheel Hubs Check and Adjust (with wheels removed) This was already done once on B Service in September 2004!

Why? I agree w/you .. Who cares if it has float. .001 to .003" is ok and if the seal is not leaking and it was properly sealed with grease why pay to check it again. Sounds a little to me.

£50 (9) Cover On Rear Final drive Unit Remove / Install, Seal ( Rear Final-Drive Unit Removed)

Is this for the leak? also is it really necessary to remove the final drive for service. I have never pulled one on a Mercedes but the corvettes, gm cars, and fords can be serviced in the car. Perhaps this is just the labor to get to the defective seal.
£270 (10) Rear Final Drive Unit Remove/Install

Same question as above.

£30 (11) Road wheels (2) Remove /Install

Why? are you just rotating tires are having fun pulling wheels?

Not for the $2000 price I hope you have other options for service and also consider service from the dealer as part of buying the car. No service don't buy any car. Don't know if this helps but just my thoughts on the work given the limited data presented. I can't see the car but if it has 18,000 miles as you described the items listed seem a bit excessive.

Good luck and hope you ask all the "right" questions for service. Jim

 

Thats bollo*ks if its a sealed unit why is it part of a service when vehicles do over 50k? change the fluid and the filter need about 4-5 litres of ATF.

 

transmission plug is a common problem. THe fluid passes through the rubber washer and goes up the electronic plug up the wire. There is a repair kit with silicone rings. Remove the small sheild around the pan and you will see the screw in connector. Remove the plug. Use a 7mm socket and remove the socket. Replace the socket. Clear the plug with brake cleaner and dry it.

 

Just a quick update. I am going to the dealer tomorrow to order the repair kit and get some ATF and new filter.

Will keep everyone posted.

I just noticed, this is a year later. I need to get motivated a little more.

 

Look into AMSOIL's ATF. Looks to be a solid product.

 

All my dealer had was the rings and those just came in yesterday after a 3 month backorder. They siad the part the rings go on is on back order. MB has 7200+ on backorder. They knew exactly what I was talking about as soon as I said transmission fluid leak.

Will replacing the rings be sufficient? I hope to do this tonight or tomorrow night.

I also picked up a transmission pan gasket, filter, and 6 litre's of ATF MB. Thanks for the suggestion and if I need more I will try the above. I am sure they don't my arm and leg to buy it like MB.

Stupid question: My wife's C240 is at work but do they have a dipstick for the tranny fluid?

 

Jim, the reason they're recommending the plug change is they are 5 years old. My manual says 5 years or 100,000 miles.

 

I have the same exact problem. I changed trans fluid, filter and changed pan gasket. When I was under there I saw the trans plug leaking, I was scared to touch it. I removed heat shield to get a good look at the sucker and it is leaking. My question is, is the hex bolt on the outside or do I have to drop trans pan to get acess to hex bolt to remove trans plug? Also car is a 99 with 70K can I just order o rings or do I need the spacer too?

 

the hex bolt is inside the connector. Twist the connector off at the collar. There is a 7mm (I think) bolt inside.

 

Do I have to take trans pan down to get to hex bolt for trans plug, will I lose fluid?

 

What sunil said above. You don't have to drop the pan. The bolt is inside the plug.

Yeah, you may loose a little fluid so be prepared for that but not an overwhelming amount.

There is an updated p/n for the W203 and you need to buy the whole plug. It's $8 or something.

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