722.357 automatic transmission adjustments - PeachParts Mercedes-Benz Forum

Vilnis · #1 11-02-2014, 09:38 AM

Hello everyone!

My w124 OM603 is shifting strange. Sometimes it has really hard shifts, sometimes flaring.
All the vacuum connections are ok and valves hold vacuum pretty well.
I have new vacuum pump that gives good vacuum and VCV is draining vacuum pretty well: 10-0 in is atchieved when playing with throttle.
So I quess next step is to test and adjust vacuum modulator on transmission. I did not adjust VCV until modulator is adjusted properly.
This is where I stopped. My trans model is 722.357 and I cannot find propper pressure value that should be on the test port.
All the manuals mention 722.358, 722.359 and other models but nothing about 722.357. Few threads in google, but no pressures mentioned.

Could anybody share this number?
I have read that this pressure could be measured in P and idling. Is this true?

Second question is Bowden cable. How free it should be if throttle isn't touched.

Regards,
Vilnis

Junkman · #2 11-02-2014, 02:18 PM

I found a manual listing pressures. They were very close for a given color of modulator. I'll try to find it. Try searching "Mercedes 722 transmission Mitchell" in the mean time.

300TD1982 · #3 11-02-2014, 08:46 PM

I don't have info for your version either, sorry. But this may be of interest:

722.3xx
Set PSI at 31 MPH

.301 Green 51
.303 Green 42
.304 Red 51
.309 Red 41
.310 Red 57
.311 White 48
.312 Red 54
.313 Red 58
.315 Green 42
.317 Black 46
.320 Black 57
.321 Black 46
.323 Red 58
.324 Green 52
.342 Black 58
.350 Black 55
.351 Black 58
.352 Red 55
.353 Black 59
.355 Black 55
.358 Black 58
.359 Red 55
.361 Red 55

cheers.

Vilnis · #4 11-05-2014, 10:26 AM

I have Mitchell manual, I guess, but nothing with my transmission model.

It is also interesting that I have blue modulator. Above mentioned models don't have any blue modulator. Maybe some smart ass previous owner put in something without thinking about this.

JamesDean · #5 11-05-2014, 12:53 PM

If you remove vacuum completely does the transmission shift hard all the time? If it slips...then you likely have an internal problem unrelated to vacuum.

If it shift hard all the time then I would plug up other vacuum lines, namely the HVAC and rear head rests. These Y off near the brake booster. I found that many of HVAC pods are bad and sometimes during certain operations it would expose a vacuum leak effecting the transmission.

Vilnis · #6 11-06-2014, 01:00 AM

Ok, I will try this today. Thanks.

Quote:

Originally Posted by JamesDean

If you remove vacuum completely does the transmission shift hard all the time? If it slips...then you likely have an internal problem unrelated to vacuum.

If it shift hard all the time then I would plug up other vacuum lines, namely the HVAC and rear head rests. These Y off near the brake booster. I found that many of HVAC pods are bad and sometimes during certain operations it would expose a vacuum leak effecting the transmission.

Stretch · #7 11-06-2014, 10:03 AM

Quote:

Originally Posted by Vilnis

Hello everyone!

My w124 OM603 is shifting strange. Sometimes it has really hard shifts, sometimes flaring.
All the vacuum connections are ok and valves hold vacuum pretty well.
I have new vacuum pump that gives good vacuum and VCV is draining vacuum pretty well: 10-0 in is atchieved when playing with throttle.
So I quess next step is to test and adjust vacuum modulator on transmission. I did not adjust VCV until modulator is adjusted properly.
This is where I stopped. My trans model is 722.357 and I cannot find propper pressure value that should be on the test port.
All the manuals mention 722.358, 722.359 and other models but nothing about 722.357. Few threads in google, but no pressures mentioned.

...

The data I have (from WIS) is

Vacuum unit => black; modulating pressure 3.2 bar; converter diameter 270mm

Also an alternative blue vacuum unit with "Feed B1 modified" what ever that means - this is only applicable to transmissions with part number => 124 270 21 00

'Hope this helps

Vilnis · #8 11-06-2014, 03:36 PM

Removed Vacuum line from modulator and transimission shifted hard in all gears. So I guess transmission internals are fine.

What is HVAC ?

Quote:

Originally Posted by JamesDean

If you remove vacuum completely does the transmission shift hard all the time? If it slips...then you likely have an internal problem unrelated to vacuum.

If it shift hard all the time then I would plug up other vacuum lines, namely the HVAC and rear head rests. These Y off near the brake booster. I found that many of HVAC pods are bad and sometimes during certain operations it would expose a vacuum leak effecting the transmission.

JamesDean · #9 11-06-2014, 03:41 PM

HVAC = Heating Ventilation and Air Conditioning.

If you look near the brake booster you should see three vacuum lines. One is a straight line the other 2 are Y'd into a single line.

One of the Y lines is the HVAC (green on my car). Remove this line and plug up the hole with a screw or something so that it does not leak.

Reconnect the vac to the transmission and go for a drive, see if you have an issue still.

I'd also recommend that you pick up a MityVac or equivalent vacuum gauge/measuing device so you can better trace down these problems.

Vilnis · #10 11-06-2014, 03:42 PM

Thanks for the info. Do You have numbers for blue unit?
That is quite interesting because I have 124 270 87 00 722 357 0 3688785.

Would You please look what modulator do I need?

Quote:

Originally Posted by Stretch

The data I have (from WIS) is

Vacuum unit => black; modulating pressure 3.2 bar; converter diameter 270mm

Also an alternative blue vacuum unit with "Feed B1 modified" what ever that means - this is only applicable to transmissions with part number => 124 270 21 00

'Hope this helps

Vilnis · #11 11-06-2014, 03:55 PM

Oh, I see, will try that too. Thank You very much for suggestions.
I have mityvac in trunk. If these HVAC lines are bad they should leak?

Quote:

Originally Posted by JamesDean

HVAC = Heating Ventilation and Air Conditioning.

If you look near the brake booster you should see three vacuum lines. One is a straight line the other 2 are Y'd into a single line.

One of the Y lines is the HVAC (green on my car). Remove this line and plug up the hole with a screw or something so that it does not leak.

Reconnect the vac to the transmission and go for a drive, see if you have an issue still.

I'd also recommend that you pick up a MityVac or equivalent vacuum gauge/measuing device so you can better trace down these problems.

Stretch · #12 11-06-2014, 04:10 PM

Quote:

Originally Posted by Vilnis

Thanks for the info. Do You have numbers for blue unit?
That is quite interesting because I have 124 270 87 00 722 357 0 3688785.

Would You please look what modulator do I need?

According to the information I have 124 270 87 00 should have the black vacuum dashpot.

The modulator pressure is stated to be the same for all combinations of the 722.357

The foot note for 124 270 87 00 says "D89 (using memory spring)" - I don't know what that means - I guess I'd have to read through the manual to find that out. I don't think it makes any difference to the adjustments though.

Vilnis · #13 11-06-2014, 04:18 PM

OK, so at last I have exact number for modulator - 3.2 bar. Something to start with.
I am curious what could be the difference between blue and black modulators. I guess if I cannot make any good results with this modulator, then I should change it to black one.

What is this WIS You are using? Maybe I should get one too.

Thank You very much for Your response.

Quote:

Originally Posted by Stretch

According to the information I have 124 270 87 00 should have the black vacuum dashpot.

The modulator pressure is stated to be the same for all combinations of the 722.357

The foot note for 124 270 87 00 says "D89 (using memory spring)" - I don't know what that means - I guess I'd have to read through the manual to find that out. I don't think it makes any difference to the adjustments though.

Stretch · #14 11-07-2014, 02:56 AM

Quote:

Originally Posted by Vilnis

OK, so at last I have exact number for modulator - 3.2 bar. Something to start with.
I am curious what could be the difference between blue and black modulators. I guess if I cannot make any good results with this modulator, then I should change it to black one.

What is this WIS You are using? Maybe I should get one too.

Thank You very much for Your response.

Mercedes has a technical support network that consists (amongst other things) of an electronic parts catalogue (EPC) and technical information (WIS) - I'm not sure what the acronym WIS is for - perhaps something information system - it could also be in German...

...anyway as we both live out side of the US of A we have to pay for EPC. This is about 100 euros a year but you can get it included as part of a membership deal with certain Mercedes classic car clubs.

WIS, however, is a much more expensive database to access. It gives you the service updates and more in-depth technical information than that which is given in the factory service manual (FSM). You can in principle buy short time access to WIS as well so you don't have to pay the thousands of euros asked for the whole year.

The downside to all Mercedes on line technical information is that it is only accessible with a certain mutant version of Microsoft Windows - you have to to tune your computer to be as back dated as their systems. It is a nightmare. Even Mercedes seem to acknowledge this as any subscription sold only starts once the buyer has miraculously managed to log on to their system!

JamesDean · #15 11-07-2014, 08:26 AM

Quote:

Originally Posted by Stretch

Mercedes has a technical support network that consists (amongst other things) of an electronic parts catalogue (EPC) and technical information (WIS) - I'm not sure what the acronym WIS is for - perhaps something information system - it could also be in German...

...anyway as we both live out side of the US of A we have to pay for EPC. This is about 100 euros a year but you can get it included as part of a membership deal with certain Mercedes classic car clubs.

WIS, however, is a much more expensive database to access. It gives you the service updates and more in-depth technical information than that which is given in the factory service manual (FSM). You can in principle buy short time access to WIS as well so you don't have to pay the thousands of euros asked for the whole year.

The downside to all Mercedes on line technical information is that it is only accessible with a certain mutant version of Microsoft Windows - you have to to tune your computer to be as back dated as their systems. It is a nightmare. Even Mercedes seem to acknowledge this as any subscription sold only starts once the buyer has miraculously managed to log on to their system!

Not to contradict you, I know some have had problems with the EPC but in my 7-8 years of usage I've not had any problems related to starting it up in Windows. That covers 7 and 8, 8.1.