722.608 tranmission characteristics - PeachParts Mercedes-Benz Forum

Rafi · #1 10-16-2004, 07:58 AM

I need your input. I am not familiar with 722.6 transmission characteristics and I bought the car used recently 99 E300 turbodiesel with 94 K mi. I do not know its history beyond Carfax. there were no issues on Carfax.

This is my experience, after you back up and move the shifter to drive and if the car is still rolling back a bit, the transmission engages forward very abruptly like you hit a wall on the back, but if you come to a complete stop then move the shifter there are no issues, is this normal? Also the shift from 1 to 2 can be abrupt specially if the accelerator is pressed hard. The rest of shifting is OK and down shifting is OK.

Would changing of ATF help any or what should I do?

Southern · #2 10-16-2004, 11:04 AM

The first issue I would not know about - I would never shift any car into drive with the car still rolling back. I cringe when I see other people do this to their cars.

The second issue I would suggest that you drive the car for two weeks and let the trans computer adjust to your driving habits. You might consider having the trans fluid level checked expecially if you don't know the history of your car.

There are mixed thoughts about changing the trans fluid on the 722.6 transmissions. I am from the old school and don't believe that any fluid is "fill for life". I changed my trans fluid/filter around 80K miles and the fluid looked dirty as well as a thin layer of sludge on the bottom of the pan. Keep in mind that the 722.6 requires special trans fluid (around $12/liter) and a special tool to measure the fluid at a specific temperature.

arkie · #3 10-16-2004, 11:20 AM

Took my '98 ML320 to German Auto Tech in West Memphis, AR yesterday for diagnosis of CEL. I asked him about the transmission oil, and Mercedes' claim that it is "filled for life". This guy has been working on MB for over forty years - he says that "life" means 100K miles as far as MB is concerned. He had changed the fluid in another '98 that very day and he said it was BLACK. I am at 92K, and I will pay the bucks to have it changed at 100K.

arkie · #4 10-16-2004, 11:24 AM

Also, on the changing FWD/RVS while rolling - DON'T do it. It overloads the internal mechanisms of the tranmission. Its especially hard on the clutches. I am 100% convinced that any transmission that has to be replaced before 100K (that didn't have some factory defect) has probably suffered from the forward/reverse-while-rolling ABUSE.

Rafi · #5 10-17-2004, 01:52 PM

Thanks for the input. Why is it considered abuse if you let it roll back slightly ? I have done it in all my cars and I had no problems. This car if you are standing on a hill and let go of the break the car does not roll back by itself. I was wondering if it was just my car or all 722.6 do it? I will shift after a complete stop. What about the 1 to 2 harder shift, is that an issue? I was hopeing the other experts would chime in as well, you know who you are.

In regards to fill for life the answer I got varied responses from 100 K to 150 K mi. Once I figure out how I can get it done, I will have it done, I have the right ATF fluid from MercedesShop. The optional dip stik. I have read the ATF posts and 722.6. I will go to the dealer as a last resort. I hate to see the guy with white lab coat coming may way, I know I am about to get a proctological exam. Whats up with that, white lab coat in a garage.

dtf · #6 10-17-2004, 07:02 PM

I have the same car. I am assuming that you have the W/S button on S when describing the abrupt shift from 1 - 2. I agree with rjnonnie and wait a few weeks until you and the car become used to each other. My wife is the primary driver of our car while I drive the '94 wagon. I find that it is a little abrupt when juicing it (which I do all the time

) and sometimes I put down rubber from a standstill

. Fun car to drive, let it get to know you. Some common problems are starting to show in this car like glow plugs, MAF (mass air flow) meter, some motormounts, plastic fuel lines crack - also have the spring perch for each front tire checked. I think MB fixed this by '99 but just to be safe...BTW the car is pretty good in the snow with Hakkapeliitta's on it. Don't worry about the lab coat - I've seen a guy work on my car with a hair net, nitrile gloves and a lab coat.

manny · #7 10-17-2004, 07:40 PM

Quote:

Originally Posted by dtf

I've seen a guy work on my car with a hair net, nitrile gloves and a lab coat.

Hmmmmm.....sounds like MY doctor ( getting ready for his & my favourite........... prostate exam ).

Hatterasguy · #8 10-17-2004, 08:06 PM

Quote:

Originally Posted by Rafi

Thanks for the input. Why is it considered abuse if you let it roll back slightly ? I have done it in all my cars and I had no problems. This car if you are standing on a hill and let go of the break the car does not roll back by itself. I was wondering if it was just my car or all 722.6 do it? I will shift after a complete stop. What about the 1 to 2 harder shift, is that an issue? I was hopeing the other experts would chime in as well, you know who you are.

In regards to fill for life the answer I got varied responses from 100 K to 150 K mi. Once I figure out how I can get it done, I will have it done, I have the right ATF fluid from MercedesShop. The optional dip stik. I have read the ATF posts and 722.6. I will go to the dealer as a last resort. I hate to see the guy with white lab coat coming may way, I know I am about to get a proctological exam. Whats up with that, white lab coat in a garage.

The way I understand it you need a special tool that plugs into the cars computer to measure the fluid temp. It has to be exactly 80C to get a proper reading on the dipstick. It really is a dealer only job.

Rafi · #9 10-18-2004, 08:02 AM

Yea I heard the scared posts of special tools and such. The dip stick also has markings for 25 C level check. Also has anyone use the BG ATF flush system? It sounds really cool. Check out their website, it also has video of theri products in action.

Yes the 722.6xx is the 5 speed trans with W/S switch.

http://www.bgprod.com/bgprofessional/bgproducts/dline.html

Manny - I think you enjoy your exams too much.

Hatterasguy · #10 10-18-2004, 11:15 AM

The way I look at the $5k figure keeps getting floated around for how much one of these tranny's cost, and after Gilly saying that if the fluid level isn't right you could cause damage. Also that you need special super expensive computer to give you a anccurite fluid temp reading. $300 every 100k seems cheap to me, I would just bring it to the dealer and not overthink it. Or don't change it just as many techs say change it as say don't worry about it.

Rafi · #11 10-18-2004, 05:15 PM

As long as you use the right fluid and fill it to the right level then there is nothing more to it. Plus how do I know the dealer will do it properly since the effect of a poor job may only show up after a few months.

There is a rebuilt site on ebay for ~1,800.

http://stores.ebay.com/Phoenix-Remanufactured-Transmission_W0QQsspagenameZl2QQtZkm

I am going to stick a wire thermocople down the tube to read the ATF temperature and then do the final level check.

Southern · #12 10-18-2004, 09:31 PM

Rafi,

I suggest that you drive you car for 20 minutes to get it up to operating temperature and check the level before you change the trans fluid. This will give you an indication of potentional trans fluid leaks and hopefully peace of mind that the car's been driven with the proper trans fluid level.

When I changed my trans fluid, I checked the level before and measured the amount of fluid that came out. Since the level was at the 25C mark with the engine at operating temperature, I put in the same amount of new trans fluid that I took out. When I checked the level it was at the same point originally.

The measuring method is not the correct method but it worked for me.

The main reason I did my own trans fluid change was that the local dealers would not do a trans fluid change when I offered to pay them for this service. They said that the trans is "sealed for life" and does not require this service.

When I completed the trans fluid/filter change, I realized that it was no more difficult than changing the trans fluid on a GM vehicle.

I wouldn't recommend a DIY trans fluid change for anyone who is not 100% confident that they can do it themselves. A botched up trans fluid change can cost the price of a new trans.

Benz288 · #13 10-19-2004, 02:42 AM

"Why is it considered abuse if you let it roll back slightly ? I have done it in all my cars and I had no problems."

Simple mechanics I guess. Making sure the car is in a complete stop before shifting from Reverse to Drive makes it easier for the transmission gears to engage.

I have the 722.6 transmission as well and I don't dare to abuse it, let alone shift to drive while the car is still rolling back. A quick search may be quite enlightening.

Ed Richardson · #14 10-19-2004, 11:03 AM

If your model has the W/S switch it will lock the reverse roll if the switch is in the "W" position. It should not lock in the "S" position.
Ed

mctwin2kman · #15 10-19-2004, 11:48 AM

Quote:

Originally Posted by Benz288

"Why is it considered abuse if you let it roll back slightly ? I have done it in all my cars and I had no problems."

Simple mechanics I guess. Making sure the car is in a complete stop before shifting from Reverse to Drive makes it easier for the transmission gears to engage.

I have the 722.6 transmission as well and I don't dare to abuse it, let alone shift to drive while the car is still rolling back. A quick search may be quite enlightening.

Also note that when shifting from R to D and the car is rolling, the output shaft of the tranny is going in the opposite direction, then you want it to switch while it is still rotating, causing excess and un- needed wear and tear on the gears and rest of the tranny internals. Why would you want to cause more wear and tear and in time damage just so you can save a few seconds?