First post and I hope you can help me and my brother out....My brother has a '05 C240 that has been acting up on him. The auto transmission will intermitantly stop working...He will be driving and all of a sudden the transmission will....not work....it acts like a manual transmission when the clutch is pushed in...the connection between the motor and wheels is suddenly lost. it did this a few times before He had the transmission fully serviced and drove fine for about 2 weeks...then it started doing it again. When this happens he can turn the car off and let it sit for a minute or two and start it back up and it will work just fine, other times it won't work at all... The service guy said that the torque converter seemed to be whining a bit more than normal so we are thinking there is a lot of dirt built up in the TC/tranny. The car has about 90K miles on it and he never changed the tranny fluid until this happened(He doesn't know the importance of changing the fluids in the car regularly)...which leads me to believed there is dirt clogging the filter and not allowing the tranny to work as it should...But this is the first Euro car that I have worked on. This has kept him from driving the car for about 4 months now and has been driving my Vehicle. Now the weather is changing and I don't want to be riding my Ducati in the ran and cold...his other vehicle is used as "the baby mobile" so getting his car back up and running a pretty big and important deal...any help is greatly appreciated.. from the research I have done it is a 203 chassis...I am pretty mechanically inclined since I do all my own vehicle maintenance on all my vehicles...I do have the manual as well...but it won't tell me if the TC is the issue or maybe something else is to blame for the tranny to do what it's doing...Thanks in advance..

 

This can be a number of things. One of the transmission "limp" (protection) modes is to give you no drive. If you slammed the car into reverse while moving forward this would happen. Get an OBDII scanner that reads transmission codes & see if it's storing codes & what they are. OBDII plug is under a rectangular flap under the steering column in the cabin.

- I would pull the pan & change the filter again
- Check the electrohydraulic valve body
- Check the Electrohydraulic bush for the typical O ring oil leak & make sure that oil is not wicking up the harness to the TCU under the passenger kickplate in the cabin. If oil gets into the TCU things get expensive.

If it reliably regains drive after a reboot of the TCU by restarting I would start by checking the electrohydraulic bush for oil leaks. (Sounds as if a reboot does not always work - but nevertheless). It unlikely that the TC will give you zero drive unless it's getting no fluid which might mean another clogged filter.

See 115 - RHS front diagonal of the transmission under the car - wiring leads to TCU.











Please read:

https://mbworld.org/forums/attachmen...e-campaign.pdf Ignore VINs

Check for oil on front floor & wiring to TCU

 

As Glyn said above, "pilot bushing" should be the first thing to check. New pilot bushing is $8 at on-line parts stores and $9 at MB dealer. It's relatively easy to change. The o-rings on that pilot bushing wear out and allow the trans oil to leak in to the electrical connector.

There may be a metal cover covering the pilot bushing; so, you may not see the pilot bushing connected to the side of the trans pan.
There is a tab on the outer part of the connector, turn that tab counter-clock wise about a quarter of turn, then pull out the electrical connector. Then use 7mm socket and gently remove that single bolt holding that bushing. Pull out the bushing. Make sure the old o-rings are out. They tend to stay in side that cavity. Put the new bushing in, carefully wiggle the bushing into it's place, tighten the center bolt. Put the electrical connector into the bushing. Twist the tab clock-wise about quarter of a turn. That's it.

 

I second Glyn & PCY's recomendation, the same thing happened to me and it was the pilot bushing, my symptom was the tranny got stuck in one gear and would not change, drove 30miles in second gear and got it fixed under warrentty, now i have 2 of these bushing in stock if it ever happnes again I will DIY it.......

hope yours is the same.........

javvy...

 

my 03 c240 that i had did this too.

 

hooked up my codes reader and got 2 codes....

P0715 Input/Turbine Speed Sensor Circuit Malfunction

P0730 Incorrect Gear Ratio

Any ideas??
dropping the fluid pan and looking at what has been suggested so far....

 

Those codes are really meaningless. To be expected if there is any slip in the box.

 

i go the pan down and pulled the electrohydraulic plug connector and there was oil on it...but how do I get the bushing out?? took the filter out and saw that the felt filter material looked like it was trying to get sucked up the tube that goes into the valve body. Took the filter apart from there and found some dirt that was caked under the felt material where the tube is... we'll see tomorrow when I finish up how it all runs...

What color is the tranny fluid supposed to be?? the stuff I had came out brown...I've always thought tranny fluid was reddish...

 

Oops, looks like more than one problem. Dirt & bush. Please guys service your transmissions every 38,000 miles

- Clean as much crap out as you can & replace filter - don't dismantle the electrohydraulic unit unless you are very confident as a DIY'er. Flush the cooler lines
- Fluid colour for confusion is red in the US & pale green/straw colour in ROW.
- Remove plug by twisting - pull out then undo captive 7mm & remove bush

Here's a full DIY & also see transmission filter change. Read the pdf's I have attached above in the pics from MB on the bush campaign & below on transmission flush.

http://www.installuniversity.com/mb/...on-o-ring.html

Electrohydraulic unit

 

cleatus, based on the your description of the quality/color of the trans fluid, your trans indeed needed a service. Changing the trans filter, fluid, and the pilot bushing is a good start. About how to change the pilot bushing - please look at the picture posted by Glyn above. Specifically, the picture that is looking right in to the pilot bushing (pins showing). You will need to remove the 7mm screw that is right at the center of the pilot bushing. You will need a long socket or a short socket with 3" extension.

I just saw the link Glyn provided (from installuniversity) for the instructions on changing the pilot bushing. That should help you.

 

Sorry - This thread keeps loosing images I attach - I have reconstructed above.

 

Thanks guys....I will be removing the bush toda. I have all the tools to remove it. My brother doens't understand the importance of scheduled fluid changes..but I think he does now..His '05 Duramax was running rough and we changed the oil....came out like mud....now it drives much better after the oil change...I think I have become his mechanic

 

Good luck!

 

well after a complete fluid flush, cleaned and dried the electrohydraulic connector and new oil and filter it seems to be running great. the fluid was dirty. The filter material was clogged to the point that it was getting sucked up into the tube going to the valve body. will change the filter one more time before he trades it in...

 

Good news - Did you replace the $8 bush & O Rings? You must or you will be back in trouble. You have to stop the O Ring leak. We all carry spares they are so cheap.

 

well it did it again....New filter in hand....Glyn....you have a link to where I can purchase this bush and O-rings...not sure if this is it or if the fluid is just so dirty that it keep clogging the filter. Also is there a place I can buy the tranny fluid over the internet? and what type id fluid does it take??? My searches on have came up with nothing so far...

 

If in the US

http://www.rmeuropean.com/mercedes-parts.aspx#Category

Fuch Titan 4134 Fluid

 

That trans fluid is for '08 c300 7 speed trans. Will this work in my 5 speed trans.??

 

Yes - also recommended for the 5 speed & the best possible product you can put in the 5 speed.

 

Thanks...for all the help..

 

No problem. The new fluid is just a longer life version of the older one with better components & synthetic base oil. It's intended to maintain shift quality for longer etc.

 

Any idea where to get the adapter that threads on the banjo bolt?

 

Please explain what you are talking about.

 

I removed the banjo bolt, when I realized I needed an adapter to thread on the bolt... This is for two reasons:
1) Generate clamp force on the return cooling line.
2) To connect the drain hose (with a hose clamp).
It looks like an adapter is shown in the pdf.

 

Dealer.