New car, new problems
Minor
-Rattle in the sunroof/moonroof panel
-Squeak/rubber-on-rubber sound from steering wheel at low speeds
Major
-When the car shifts from second to third gear the car revs before going into third. I'm hoping it might be electrical, but a mechanic told me the transmission had to be overhauled.
Any ideas/advice on fixing these problems would be greatly appreciated, thanks!

1) - There is a fix for sunroof rattle - usually the interior panel rattling when fully opened.
2) - There is a rubber boot where the steering shaft exits the firewall. There is a repair for that too.
3) - Transmission slippage usually indicates a problem but anyone can throw in a rebuilt. Have the car's computer scanned for transmission codes and see what turns up. Have you had the transmission fluid level properly tested? That is critical on your 722.6 5sp.
Do some searches on 1) and 2) which are fairly common problems.
I took it to a mechanic whom I asked to check/change all fluids and do a full inspection. Unfortunately that didn't seem to help, so I took it to a transmission shop which told me it needed to be overhauled since the transmission is beginning to slip?
I bought warranty from the dealer which covers up to 2500$, but the other 1000 i'd have to shoulder on my own so I'd still end up with a decent deal for the vehicle even with the transmission rebuild as the car runs perfectly fine otherwise.
But on a good note, i'll search up and fix those minor issues, its good to know that its a pretty common problem so that eases my worries a bit. Thanks a lot for the info!

1) - There is a fix for sunroof rattle - usually the interior panel rattling when fully opened.
2) - There is a rubber boot where the steering shaft exits the firewall. There is a repair for that too.
3) - Transmission slippage usually indicates a problem but anyone can throw in a rebuilt. Have the car's computer scanned for transmission codes and see what turns up. Have you had the transmission fluid level properly tested? That is critical on your 722.6 5sp.
Do some searches on 1) and 2) which are fairly common problems.
Last edited by E320User; Jul 12, 2011 at 11:49 PM.
These cars have a 'sealed' transmission. There is no dipstick in the transmission dipstick tube just a cap with seal. To check the level correctly, the transmission must be fully warmed up, parked on level ground and a special 'dipstick tool' inserted to check the level. Most mechanics or transmission shops might not have the tool or know the correct procedure. Try a indy shop specializing in Mercedes or a dealer to get a proper check and get the codes read before spending $3500.
I don't think the other problems are serious enough to warrant a DIY so you'll have to search for threads related to the problems but I know I've seen them mentioned here and on Benzworld.
Last edited by RichardM98; Jul 13, 2011 at 10:03 AM.
Sorry i'm pretty new to this lingo, and i'm not exactly the worlds top mechanic either lol but I'll definitely get these checked out before doing a transmission rebuild, because I heard a rebuilt transmission will only last around 50-60k km's before it starts getting ugly again!
These cars have a 'sealed' transmission. There is no dipstick in the transmission dipstick tube just a cap with seal. To check the level correctly, the transmission must be fully warmed up, parked on level ground and a special 'dipstick tool' inserted to check the level. Most mechanics or transmission shops might not have the tool or know the correct procedure. Try a indy shop specializing in Mercedes or a dealer to get a proper check and get the codes read before spending $3500.
I don't think the other problems are serious enough to warrant a DIY so you'll have to search for threads related to the problems but I know I've seen them mentioned here and on Benzworld.
The transmission codes are stored whenever errors occur in the transmission operation. Unlike the generic codes any of us can scan with an OBD scanner, they require a MB Star Diagnostic System. All dealers have one and sometimes a very good MB independent shop will have one. If they are indy shops in your area you might try calling around to see if any have an SDS. If the car was recently purchased from a MB dealer they may be able to help.
The 722.6 transmission in your car is very strong and one properly rebuilt should last a lot longer than 60K.
FYI, have you heard of 'limp home' mode? If not, it's a condition that the cars computer can cause so that a problem won't damage the transmission more seriously. Generally, the CEL (Check Engine Light) comes on and the car will not shift gears. The car will drive but you will be limited to one forward gear (usually 2nd) and reverse. I mention this because car problems generally don't fix themselves. Just a heads up in case it happens to you.
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Another thing that's really killing me is the CD player, when I look in the back there is 5 wires, 2 orange ones (the fiber optic wires) and the blue,black,brown wires. Well my dad tried to surprise me by fixing it himself and cut the two orange ones, is there anyway of getting new ones and replacing it myself or do I have no choice but to bring it to Mercedes Benz to get it fixed?
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Another thing that's really killing me is the CD player, when I look in the back there is 5 wires, 2 orange ones (the fiber optic wires) and the blue,black,brown wires. Well my dad tried to surprise me by fixing it himself and cut the two orange ones, is there anyway of getting new ones and replacing it myself or do I have no choice but to bring it to Mercedes Benz to get it fixed?
As for the CD wiring issues, you might want to post in the Audio/Electronics forum on this site. If the wires you are referring to are part of the car's wiring harness then probably splicing is the only reasonable option. CD changers are problematic, hold only 6 CD's and you have to stop the car to change them. A better solution is to add an AUX-IN cable to the radio and use an MP3 player.
My appointments on the 26th!
A- CUSTOMER STATES THE TRANSMISSION IS SLIPPING FROM 2ND TO 3RD GEAR WHEN ACCELERATING. CHECK AND ADVISE.
SHORT TEST PERFORMED
INDIVIDUAL PARTS OF AUTOMATIC TRANSMISSION:... CHECK
ACCORDING TO FAULT CODE
AUTOMATIC TRANSMISSION SHIFT DELAY CHECK
SUSPECT 2-3 SHIFT VALVE DEFECTIVE CHECKED AND CONFIRMED THE TRANS IS SLIPPING FROM 2-3. HOOKED UP DAS AND SCANNED FOR CODES. NO FAULTS FOUND IN SYSTEM FOR TRANSMISSION. CHECKED FLUID AND FOUND IS OK. LEVEL AND FLUID CONDITION IS OK. TO FULLY CHECK TRANSMISSION MUST REMOVE PAN AND CHECK INTERNALS. HAVE SEEN BEFORE THE 2-3 SHIFT VALVE GOING BAD. RECOMMEND STARTING WITH THE 2-3 SHIFT VALVE AND REPLACING TRANSMISSION FILTER.
and that costs... 644.70$, cheaper than the transmission rebuild, but the guy said that if this doesn't work then i'd probably have to do a transmission rebuild. What do u guys think?
Fluid for change is about $120 + $20 for filter and gasket. Price of valve $? and the rest is labor.
This is why I urged you to check it out before throwing in a rebuilt. Even if you have an indy do the work (~ $300-400) you are way ahead of the dealership.

Fluid for change is about $120 + $20 for filter and gasket. Price of valve $? and the rest is labor.
This is why I urged you to check it out before throwing in a rebuilt. Even if you have an indy do the work (~ $300-400) you are way ahead of the dealership.
For the drain plug you'll need a 5mm hex socket head. For the pan mounting bolts you need T30 bit. To set final level you'll need the 'dipstick tool' (Part No. 140 989 15 21 00). Available online or from poster Ohlord. Fluid is special (Part No. A001 989 21 03 10) but you can also use (Part No. A001 989 45 03 13 for the 722.9 7 sp trans).
The problem is that only draining the pan gets about 4 liters out of 8 liters (still about ~ 4 l in torque convertor and lines/cooler/etc.). Some people have addressed that by repeatedly draining out 4 l and slowly reducing the amount of original fluid. Pretty expensive approach. Others have detached a cooling line at the cooler and run the engine to activate the transmission pump and force fluid out. Make's me pretty nervous. Fortunately my 98 still has the drain plug on the torque convertor.
The important thing is to check the bottom on the pan for debris. That will give you a good clue of the condition of the transmission.



