93 300E transmission problem
 

Hello all,

Yesterday I drove home from college about 130 miles without a problem. Earlier today when I was making a short trip around town and my engine was flaring a little bit from stop. I would have to get the RPM up to about 2500 to get it moving. Then about an hour later when I was about to drive somewhere else the problem got way worse, 6000RPM to get moving. Then I knew that this problem was way too big for me to handle and am now looking for help/suggestions from other forum members.

I don't know very much about how to go about fixing things of this nature but here are some things of importance:

1. Engine starts up and runs perfectly fine, revs normally with no odd noise.

2. Reverse works normally as well

3. When I shift to D I don't feel anything, like it's still in Neutral.

4. 221k miles (I know, a lot)

I don't know what any of this means, common sense just leads me to thinks its a transmission problem, probably serious.

I'm not entirely sure a rebuild will be worth it on this car

never finished the last sentence...
 

...not entirely sure a rebuild is worth it on this car but I really hate to see it go.

I recommend having a MB-trained independent tech evaluate the transmission problem and suggest possible fixes and the cost of each. Then you can decide which option is the most viable. Keep in mind that any other used MB that you buy as a replacement may need expensive repairs to get it up to snuff.

You need to check the ATF level first
 

Check while the engine idles. FIll to the correct level with Dexron II or III.
If the level was way low (more than 2 quarts), you may have roasted the transmission.

Either way, you should change the fluid and filter, basically to see how it looks at this point, and that's about the only thing we mortals can do. If you have clutch pieces and other debris in there, it's rebuild time. If it looks fairly clean, then it may be repairable, but you should find a tranny shop to look at it.

My local MB independent installs rebuilt transmissions for your car for about $1,200. That's parts and labor, and they come with a one year warranty.

Surely your car is worth more than $1,200.

Thank you all for your help but I don't plan on doing much outside today be ause it is about -18 degrees. I also have to find a way to get back to school with out my car (130 miles away) by 9am tomorrow so basically I think the car will just sit until spring break. Hopefully it will be warmer and then I could get to doing some real thinking.

221K miles? Yours lasted longer than mine!

Mine is flaring on 2-3 and 3-4 shifts, and filters, fluid, and the K1 kit did nothing to solve the problems.

I'm driving my tranny to the ground and opting for a rebuild this summer...if it lasts that long!

B2 piston failure or broken B2 band

Adjust the modulator; turn the T handle CW two or three turns

$1200 for a rebuilt or repaired transmission installed, that’s cheap. Does it include a rebuilt torque converter, new B2 piston if needed, updated reverse B3 clutches, new bands if needed, not relined, they don’t last, all seals, gaskets, clutches changed. Secondary pump elimination kit, any valve body updates, new vacuum modulator, linkage bushings and clips.

b2 piston
 

Thanks a lot C32...from what I've read so far you are spot on diagnosing this problem. I'm gonna do some research after I get back to school tomorrow nad will probably tackle this issue over spring break. Anyone want to offer some advice on whether or not someone with no experience on a transmission can replace this part?

I have no idea what it comes with, just that he buys them from a local rebuilder.

I thought B2 piston failure caused a loss of reverse. Am I remembering wrong?

What does it mean by FLARING?? Is this like loud noise? Sorry I am not up to snuff on Tranmission lingos.

It is when the engine speeds up during the shift, like if you pushed the clutch in but did not let off the gas when shifting a manual trans.

taken from a website about the B2 Piston
 

"The symptoms of a B2 piston failure are unmistakable:

Fails without any warning whatsoever
Slips out of gear in 1st with any load
Massive flaring going into second
3rd and 4th work normally
Reverse works normally "

http://articles.mbz.org/transmission/b2/why/

I would remove the B2 cover and inspect the B2 piston, can be done with the transmission in the car. Do an search, a lot of information on this subject.

If it’s the B2 band, transmission must be removed and disassemble. Not a DIY job with no experience. Does your 300E have a 2.8 if so; the probability of a broken band is higher with a 722.4 Transmission. The only way to confirm valve body and plate must be removed.

The B2 band is applied for 1st, 2nd and 3r gear in 722.3,4 and 5 transmissions, you are thinking about the B3 band on the 722.0,1,2 transmissions or the B3 clutches in the 722.3 transmission which is reverse gear. I also sometime get confused, Too much transmission fluid in my Brain. .

it is a 2.8
 

so if I inspect the B2 piston and it's in good shape then it's the band and time to call in someone that knows what they are doing?

Also, what is the possibility that I find that the B2 piston is broken, replace it, and find out that the band is broken too. Is it possible to at least see if the band is broken without removing the transmission?

Does anybody know?

The only way to confirm a broken band without a doubt, remove the valve body and plate. You can also have a stuck B2 shift valve in the valve body, not as common as the piston and band.

C32 Amg
 

Thanks for your help, I'll get to doing this in Spring when I'm back home. Hopefully I'll report back with good news.

i always check my fluid when the car is cold. the dip stick doesn't have a hot cold marks, so i assume it is for cold.

I believe you are supposed to check transmission fluid level when it is at operating temperature.

Also, the engine should be running (since we are discussing basics).

gonna get started
 

OK so now it's spring break and I'm ready to determine the fate of this car.

I was just going through some things and is the DIY article on the 722.6 transmission fluid draining pretty close to what I'll have to do for mine (722.4 I think...)?

It's practically identical, except of course that you can ignore the rigamarole with the 80C temp measurement, special dipstick, and Dr. Z's secret profit formula (most any Dexron III will do).

update
 

so the first time I was going to raise my car the jack broke. Long story short: if you use two of those jacks that come with the mercedes one of them will break. Anyways it took some time to grow the courage to get under my car after watching that and I was able to drain the transmission pan today.

My first question is: Is it wierd that there was absolutely no metal in there considering I'm doing this all under the assumption that the B2 piston is broken? The transmission fluid looked like it was in good shape too, not burned at all.

and: Is it necessary to drain the torque converter and if it is how do I get the drain plug in the right area again?

I should be going at it again tomorrow morning, hopefully early because I have to go back to college in the afternoon and won't be doing much with the car until summer I guess.

Please don't come back here implying that you are getting under your car without safely supporting it with jack stands.

You are very young.

I hate to be morbid, but if that car had fallen on you, you could not have died fast enough.

:wings:

oh no i just left out a big part of the story
 

I have the works under there...4 jack stands, left the jack in place as a failsafe. have some old tires under there as a bigger fail safe. Trust me, I dont have the stones to get under something unless Im 110% sure it wont fall. I meant that I was going to do the jack on wheel up, put a stand there and then go around and do all four. But, I got the bright idea to try and jack up two wheels and then put two stands there and then only have to do the other wheels.

P.S. I appreciate teh concern its a nice feeling to have before I go to sleep that someone I dont even know doesnt want me to die :cool:

back to work
 

i finally got back to doing things for this problem after being somewhat busy since the last time i tried. basically i cant get the B2 piston cover to budge. I cant push it in with my fingers, not even a little bit...help?

anyone have an idea?