722.303 in bits photo shoot - Page 3 - PeachParts Mercedes-Benz Forum

Stretch · #31 08-20-2012, 03:52 AM

Quote:

Originally Posted by skaa

ARMY,

What a timely post! I have an '82 300SD, and just completely cleaned my valve body last week. I haven't put it back in, yet. I have 2 questions that I believe you can answer, as no one else, including various local MB dealers, seem to be able to answer...

No pressure then!

Quote:

Originally Posted by skaa

...

1- What exactly does the "Converter Adaption Control Valve" do? (It sits next to the 3-4 Command Valve)

...

I can't answer that question today. I might be able to find that out in the end. I would like to think a bit of reverse engineering will show the way - we'll have to wait and see won't we?

Quote:

Originally Posted by skaa

...

2- Does the Converter Adaption Control Valve have a spring with it or not?
...

The problem with the ATSG manual is that it tries to be a manual for all versions of the 722.3 - it shows information in a generic way. It doesn't always show information for a specific models.

There are differences between the "diesel" and the "petrol" transmissions perhaps this is one of them.

I have a copy of the ATSG manual that is specifically for G wagons that does not show a spring on that valve. (PM sent)

I'll crack on with the valve body next as three people so far have asked valve body related questions.

Stretch · #32 08-20-2012, 12:14 PM

Slow progress with the valve body today.

It was DIRTY. Here's an example of the muck on the dividing plate.

There are mountains of crap all over it. Lots of the valves were stuck in place. I ended up cleaning what I could with brake cleaner and then leaving parts to soak in penetrating oil before using the shank - THE SHANK! - of a 6mm drill bit to pull the stuck plugs out of their holes.

I've come across more evidence of tampering - some of the slotted heads on the screws were burred. To avoid this from happening to you, my advice is to not use normal screw drivers but to use a bit and a 1/4" drive ratchet.

I've laid out all of the valve body parts (for the lower part of the valve body) on paper and taped them into their correct position with respect to each other and in the correct orientation - well I say correct they are as I found them.

Final tip for those of you who are going to do this job - when you've finished for the day - care for your valve body. Wrap it all up and put it in a clean cardboard box well away from your wife, partner, the children, your pets, other peoples' pets, the drunk neighbour etc

Next I'm going to take the next layer of the valve body to bits and clean that up.

Then I'll go through it all and check what's what with ATSG and the FSM. As I've found evidence of "someone there before me" I'm reluctant to show what I've found so far!

rs899 · #33 08-20-2012, 01:07 PM

When you open one of those VBs up and see all the muck, you will stop spending needless money on snake oil in a can that claims to clean them. Yeah, right...how's it going to to THAT?

Stretch · #34 08-20-2012, 02:27 PM

Quote:

Originally Posted by rs899

When you open one of those VBs up and see all the muck, you will stop spending needless money on snake oil in a can that claims to clean them. Yeah, right...how's it going to to THAT?

Indeed! There's no way some flush treatment is going to shift any of that either. These valves are dead ends - there isn't any flow - that's not how hydraulics work.

I reckon if anyone wants to play about with superior shift kits you are also going to do yourself a favour by cleaning out your valve body.

If you don't want to pay for a new set of bright 1990's coloured springs I wouldn't be surprised, after 20 + years of use, that cleaning out your valve body is quite likely to make an improvement.

(Now that some one has mentioned snake oil => cue layback40!)

compu_85 · #35 08-20-2012, 02:30 PM

How hard do you think it would be to remove the valve body from the trans while it is still mounted in a car... without having the halves shift and all the little springs go flying?

Stretch · #36 08-20-2012, 02:39 PM

Quote:

Originally Posted by compu_85

How hard do you think it would be to remove the valve body from the trans while it is still mounted in a car... without having the halves shift and all the little springs go flying?

I think it is a perfectly do-able job. I found out today that there are two smaller screws that hold the main parts of the valve body together. It isn't as bad as I thought it was. (I've added an EDIT to the post on page one) I was walking through the garden holding the valve body like it was radioactive waste! - it isn't that bad.

You can loose one piece though if you are not careful.

Here's a picture showing the two main parts of the valve body assembly. The valve body proper can be seperated from the part where the filter fits just be undoing the bolts...

And here are the two screws that hold the rest of the layers together and the part (enclosed in a red square) that can fall out.

The only thing you need to be really sure of is no dust. Re-cover the bottom of the transmission ASAP. Imagine a cloud of sand / dust / muck being blown under the car and into it?

cho · #37 08-21-2012, 03:31 AM

Quote:

Originally Posted by Army

You can loose a few bits though if you are not careful.

translated according my skills:

you could make total mess ... easily

seriously, I imagine mine valve body assembly without a maze,
just a flat land on the sight ...

cheers
ChO

.

Stretch · #38 08-22-2012, 02:29 PM

Just to let you know - I've made a few edits recently to the text I posted a few days ago. I've been reading through the German FSM as well as getting my hands dirty and I found a bit more information.

Stretch · #39 08-22-2012, 02:30 PM

Quote:

Originally Posted by cho

translated according my skills:

you could make total mess ... easily

seriously, I imagine mine valve body assembly without a maze,
just a flat land on the sight ...

cheers
ChO

.

Ideally I want to get the thread to a standard where even you - yes even you! - will think "I can do that"...

Stretch · #40 08-22-2012, 05:37 PM

I think I'm almost there - I just can't find one bit in a G wagon ATSG manual and the German FSM...

...so there's still a little bit of work in progress!

Here's what I've got so far.

First the lowest part of the valve body

This is the side towards the rear of the transmission

and the front

Stretch · #41 08-22-2012, 05:41 PM

Now the upper part of the valve body (as it sits in the car)

Parts towards the rear end of the car / transmission

and towards the front

Stretch · #42 08-22-2012, 05:44 PM

Part 45 - is stuck in the valve body because there's a little ring of plastic that does not really want to come out with out destroying itself. I've left it in place.

Stretch · #43 08-22-2012, 05:49 PM

Both the ATSG manual and the FSM label the parts of the valve body in the same way as they are shown in the previous posts - in a disassembled state.

I was thinking that perhaps this way of showing where they are is helpful to those who are thinking about fitting shift kits

The attached PDF file holds the German FSM and the ATSG descriptions for each of the numbers

EDIT here's a picture version of the PDF file - image quality isn't fantastic though

skaa · #44 08-22-2012, 06:47 PM

ARMY,

The valve and spring marked ? is called the "Converter Adaption Control Valve" and its function: "The converter adaption valve reduces the working pressure in 4th gear to reduce parasitic horsepower loss". (A quote from an MB transmission rebuilder) Some 722.303 transmission versions have both spring and valve, and some only have the valve. (Gas vs diesel, US vs Europe, sedan vs wagon, etc??) I'm looking for that spring! Everyone is trying to sell me an entire valve body, $400 and up, instead of that single spring, or just a new set of springs! Mine's missing, or maybe the valve doesn't need one, per the German FSM for station wagons using the 722.3 transmissions.

Does anyone know for sure??

Thanks for the pictures, great job, as usual.

Skaa

--------------------------------------------------------------------------------------------------------------------------------
1982 300SD 400+k miles

Hit Man X · #45 08-22-2012, 06:58 PM

Nice work with the pictures.

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