Its easy to do BUT you had BETTER have the required tools to do it...they probably will not.
No kidding this is the actual Factory Procedure...Works great! reduced my wear metals by 75% and takes about an hour depending on how much looking/inspecting you do while you are under there.
You will need:
-Fluid sample kit and extractor (Blackstone)
-Differential Fluid (Dealer only 85w90 uses the same socket as the VW manuals 17mm allen, heat the bottle in hot water before pouring).
-OEM Trans Filter Dealer item ($14.40)
http://genuinemercedesparts.rtrk.com/?scid=1191126&kw=4070066&pub_cr_id=3381536415
-Pan gasket ($9.20)
http://genuinemercedesparts.rtrk.com/?scid=1191126&kw=4070066&pub_cr_id=3381536415
-14 Quarts (liters) of Mobil 1 Synthetic ATF ($13.00 per quart)
http://www.mobiloil.com/USA-English/MotorOil/Other_Products/Mobil_1_Synthetic_ATF.aspx
-Mercedes Dipstick to adjust the fluid level
Test Dip Stick for Transmission, newer cars. With Plastic handle. And special tip. For all vehicles with the electronic transmission 722.6
http://www.samstagsales.com/mercedes.htm#transmission
-14mm ID Metric thread (1.5?) Thin nut (not sure exactly so going off of memory)
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Anytime I replace the transfluid I replace the differential fluid. Its a 400 ft-lb diesel with a 5 speed torque multiplier ie LOTS of torque going thru those rear gear sets. I figure the $50 in fluid is worthwhile insurance on a $900 gear set (of course not including labor and all the other parts needed for the swap).
A dealer may tag you for $300 in labor so get this clarified before you show up and Emphasize a transmisison and Transmission cooling system flush not just a trans fluid and filter change!!! BIG DIFFERENCE! The Transmission cooling system flush purges the torque converter since there is no drain on your converter to get the old fluid out, this is what MB came up with instead.
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The procedure goes like this:
-Get the transmission to operating temperature approx 30 minutes of driving and 100C. This also mixes up the wear metals for an accurate sample
-Don't shut the engine off, using an extractor, pull a fluid sample from the transmission.
-Drive up on some Rhino ramps
-Use a jack and jack stands (or two jacks and safety stands) to support the back of the car so its perfectly level...very critical to getting the fluid level set.
TIP: use a level with the car on level ground and place it on the moonroof, that you you have a "level Reference".
-Once car is up and level compared to when it was on the ground,
-Remove the Forward and aft underside covers (and you thought it was bad having 1 on a Jetta??? LMAO).
-Proceed with the fluid change.
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-Drain the pan via the underside drain bolt, as you may suspect some fluid will still be in the pan after it stops flowing.
-Remove the pan, inspect and clean the magnets and replace filter.
-Clean the pan of all residues (non residue brake cleaner), reinstall with new gasket.
-Fill the sump with 4-5 quarts of new fluid.
-Remove the Banjo fitting (fluid return line from radiator, PAX side, upper forward region of transmission)
-Reverse the fitting, screw on the thin nut and attach a 1/2" hose to the banjo bolt use a tie wrap to secure the hose over the threads or a small hose clamp.
-Route the line to a bucket.
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-start the engine, leave trans in park, wait for approx 3 quarts of fluid to fill bucket, shut the engine off.
-Refill transmission with 3 quarts of fluid, repeat 2 more times.
Note: you may want some extra fluid so that you flush the trans system until the fluid is a clear red. You will notice the old fluid is quite blackish red from the suspended debris from the clutch packs.
After the last flush:
-Remove Hose
-Reinstall Banjo bolt in transmission
-Inspect all the pans retaining bolts (8 if I recall)
-Reinstall lower trans and engine covers
-Lower the car off the jacks and ramps.
-Using the dipstick, check the pan temperature so that its approx 80C (double check) the fluid should indicate at the full mark on the dipstick.
-Take the car for a drive to heat the fluid up (10 Minutes).
-Take another "0" Mile sample to validate the reduction in wear metals.
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-Remove dipstick and reinstall the trans seal.
Job Complete.
Good news, your transmission is now only $5296.00 plus labor to replace!
I am down in Viracopas and will be back on Monday, let me know if you need the full printed procedure.
Also, I would recomend getting the MB Service DVD, its the best $100 you can spend for your car! It has the full procedure on it and everything else required to work on your car. Much easier to use than Xentry since all other models are filtered out.