Need serious support for 722.3 transmission rebuilding
 

My W124 400E transmission gave up, it acted up and I found lots of metal chips in the pan. I decided to rebuild the transmission myself, want to be brave.
The idea is : I 'll install another used transmission that I bought on ebay and then I will rebuild the failing transmission. These are 2 separate projects really.
project#1: getting the new donor transmission ( 150K miles) re-sealed and change the reverse friction disks+ flush the cooler.
Proactively I bought a Precision banner kit 68004B for the 722.3, I believe it includes all seals, gaskets and 3 x 5 Allomatic frictions K1, B3 and K2 for .
I got the donor transmission rel. cheap and the first question is: does a product like Precision make any sense or does this call for future pain if seals and disks suck in this 'aftermarket' set?
Alternative frictions would be Borg Warner, still aftermarket but seemingly more expensive but also better? I'd need recommendations regarding the quality of available banner kits or master kits (master kits have in addition to the banner kits also the steel disks).



Second question is about flushing the cooler: with chips in the pan of the old transmission ( I guess some spring has been eaten by the tranny) how great are chances that the cooler is contaminated? I guess if the pump itself is not damaged and eaten alive and the filter worked then no chips should be found in the cooler... but I might be wrong. I am planning to flush the cooler with alcohol (ethanol) and shop air.

Any suggestions are welcome as I have the donor transmission her and will start resealing soon to get it installed in the car and hopefully drive.

Project #2 will be the rebuilding of the damaged transmission and this will be the real deal and challenge for me as soon as the car is on the road again and i have some piece of mind for focusing on the total rebuilding.
Again any help is welcome for project 1 now

I have a car lift and a transmission lift..all basic tools and some experience in hydraulics...but never opened up the transmission.
Martin

You are using what most any trans shop would be using so no problem there. Seal kits are usually packaged with parts from various sources and sometimes I've seen OE branded parts inside. ( Auto makers "make" very little of the parts in a car beyond sheet metal / assembling engines / trans. )

Do a search of the forum, there are step by step instructions somewhere. The .4 is a smaller version of the .3 and the .5 has an overdrive unit. Are all similar enough that instructions will be helpful for all.

Rebuild the trans in sections, don't just take everything apart at once. ( RE: you can take all the major assemblies out of the case but don't break down each sub assembly until you have finished reconditioning each one. )

Lay the parts out on the bench in the order that they come apart. Pick a convention so whatever parts that are facing up are to be installed in a certain direction in the trans. In older trans, there are parts ( spacers , washers ) that look like they could be installed in either direction but have subtle differences and should not be flipped over.

Buy the ATSG manual for this trans. Don't bootleg it, this company puts lots of effort into making these very good inexpensive $ 30 books and sometimes even includes real world information. https://www.atsg.us/atsg/mercedes-722-3-722-4-dl.html

The source of the failure must be found and fixed. This is easy when there is a "hard part " ( metal parts that are generally reused in a rebuild ) but can be more difficult when "soft parts" fail ( frictions / seals ) . A set of burned clutches can be replaced to get the unit going again however, if the valve body has problems, the will fail again.

Speaking of the valve body, this is an operation all unto it's self so leave that for a separate job.

~~~~~~~~~~
aftermarket.raybestospowertrain.com/allomatic.aspx

Allomatic is a brand of Raybestos Powertrain and is a leading supplier of original equipment quality automatic transmission parts.
~~~~~~~~~~~~~

Precision International – Transmission Kits

Precision

Do a search for the user: Stretch. I believe he has a very detailed transmission rebuild post with tons of pictures. It was for a 722.xxx, not sure of the last 3 digits, but there must be some similarity to them I think.

Thanks 97

Is there a difference between Precision and Transmaxx brand?
There seems to be Allomatic/Raybestos and Borg Warner frictions...
Some people say Borg Warner is better quality?

Flushing the trans cooler ? Can it be that metal chips would get into the cooler?
If yes ... is flushing enough or better exchange the radiator?

I'll get the information from ATSG and search for forum information.

Thanks, Martin

Thanks Ismalley, I'll be searching for Stretch and his information:

Damage in my old transmission: I had difficulties in the last half year. Sometimes it was not shifting accurately , but only sometimes. Then transmission seemed to slip a bit at a start. And in the end I had hard shifts but modulator was fine. I tested it. Then I found the steel chips and a piece of a spring. Chips could be a spring having been chopped up and eaten by the transmission. The chips mean I cannot use the converter any more? Or can the converter be opened and cleaned? Also the cooler could be compromised. I think I'll open also the valve body as a project and check for chips. Any suggestion?
Martin

if you see metal chips in the pan and have a non moving transmission there is definitely going to be metal in the ATF cooler, you can backflush the cooler with warm ATF first (assisted with compressed air) and finish off with LubeGard Koolerclean. It can really flush out junk. You can also get your radiator to a trans repair shop who have a cooler cleaning machine, this machine pulses hot atf into the cooler circuit agitating it back and forth to loosen debris.

The torque converter can be cleaned if you are willing enough, its a very long and slow exercise with ATF, gasoline, an input shaft and lots of sloshing around. Or you can just buy a replacement rebuilt converter - make sure its the same part number.

The kits for rebuilding are of very good quality, borgwarner/raybestos/alto/allomatic all work great. If this is your first attempt, do it in pieces so you keep track of whats what. I would also suggest you to buy some bench buddies (brushes) to clean the valvebody bores, they are fantastic for this job as they polish the bore just enough to allow the valve to drop in smoothly under its own weight.

What year is the car / transmission? Some early stuff still had a rear pump and a spring can come apart causing the gear to shear off ( leaving you with 1st gear only ) so there is some chance it came from there and go through.

In any event, you need to find where the spring came from.

I think there are 3 screws in a clutch drum that tend to come loose and would make metal.

Flush the trans cooler and add a filter to the _outlet_ of the cooler, these have a magnet to trap steel. If there isn't enough space for a filter inline, use a 360 * loop of hose on one end.

The converter will need to be replaced / rebuilt, converters make excellent centrifugal separators so in addition to clutch material, metal will be trapped. Look at a cut open converter and you will see lots of places for junk to hide.

If you take the valve body apart, be sure to work out some sort of tray to keep the parts inline, there are usually valves that can go in both ways but will only work properly in one direction. Google " transmission valve body tray " for an example. For more popular trans, they make VB specific trays but I doubt they make one for the .3 / .4 / .5

I'm not familiar with Transmaxx , but I see they have ties to Transtar, Recon, DACCO, Axiom Automotive Technologies. These companies have all been bought / sold / changed names over the years so who knows what the parent is.

Thanks 97,
My car is a 1992 400E. I think my 722.354 has a secondary pump which was omitted in the later years (is that pump to tow start the engine?). I bought another used 722.354 from eBay to get the car going and to buy some time for rebuilding the original transmission.
This means I have another torque converter but need to flush/ clean out the cooler or/ and add a filter. Any suggestions for a filter? Would a fuel filter do? What pressure is on that line? And would this be too much of resistance for the system?

Thanks Zulfigar, very helpful information. I'll consider all of it. There is some talk about tolerances in a transmission during rebuilding but the only option probably will be the size of the friction and steel plate 'packages'. Any other play I guess I need to live with like roller bearings etc? Or are there means and methods to control plays inside like shims and such?

I wanted to ask: Which side is the output side of the transmission pump? I guess the pump pushes the oil directly into the left or right side metal lines connected with banjo fitting to the transmission housing leading to the cooler.
Flushing this cooler will be one of the tasks and I should flush in reverse of the oil flow during operation in order to flush out any metal chips and other stuff hiding there.

I'll get the LubeGard Koolerclean.

Martin

I would suggest you buy the ATSG book for this transmission, It will tell you a lot of how to adjust end play of the output shaft with shims and how to test clutch pack play with a dial gauge.

It is a pretty good book. well worth the 30 dollars.

regarding the cooler lines, the driver side one is the supply to the cooler.

A fuel filter will be a bit too fine, if you have an engine oil filter base that could be made to work, just be sure to mount it filter down / dirty oil to outer edge of filter / stick a magnet to the filter to capture steel bits.

You can get filters specifically made for trans cooler lines. Check the diameter of your hose and get a filter that has matching barbs. 8 mm / 5/16" and 10 mm / 3/8". Have a look here for inline filters Service-AT Inline transmission filters Shop around as while SPX Filtran is an excellent brand, these seem $.

As for shaft end play, generally if you don't replace "stack up" hard parts, the end play will be the same as when you started. It is still a good idea to check it.

For adjusting clutch clearance, trans use different thickness snap rings , pressure plate ( the first all steel plate that is installed in the clutch drum. ) intermediate steel plates and rarely friction plates. There is a generous range of clearance and sometimes what the factory says to use doesn't work so well in the field.

Zulfiqar: I bought the ATSG book, will put it under my pillow. I have dial gauge, calipers micrometers etc. Question is where to get the shims for fine adjustments?
Thanks for confirming the drive side is the pressure side/outlet to the cooler...passenger side the return to the trans. I'll flush the cooler from the passenger side then and catch the stuff that comes out on the driver side. Will examine the fluid with a magnet.


97: What is the difference of fuel and AFT filter? Microns of filter activity? Meaning the fuel filter is too much of a resistor...I guess. There should not much resistance added..
how much flow is there really...what pressure?
Idea: I could use a cut off banjo from my donor transmission (tube is 10.0mm OD) and
get the 3/8" barbed in line filter from Makco set up at the passenger side of the trans
using a higher pressure rated hose with hose clamps. See what the second fitting looks like, machine one...and if there is space somewhere for the new filter.
The 400E seems tight down there. In the W126 is much more space.

Plumbing for an additional filter:
I just checked on site...
Best would be to cut the old rubber return line at the passenger side connecting from the cooler (banjo 19mm Hex) to the transmission steel line (M14x 1.5 cone I guess). The rubber hose is OD 15mm
depending on the ID of that hose I could choose the Filter barb ... 3/8" Filter means that the barb is for a 3/8" (9,5mm) ID hose, correct? If the ID of the hose is about 9mm it would fit then.

Martin

Project one is to get the new donor transmission going and swap with the damaged one currently in the car.

I will try and seal that donor on the outside all around, get the primary pump sealed and probably check the B3 lamellae brake frictions... I also got info to reduce the amount of the B3 springs (originally 20 springs) down to 16 or 15. Not sure exactly...

Any recommendations?

Martin

Hope you have super long extensions, takes about 3 long ones to reach the top bolts from behind the transmission.

Also get a HF trans jack or make a wooden saddle that can bolt to a floor jack to cradle the transmission as you remove it.

Replacing the rubber hose would be a good idea anyway so removing the old hose entirely then inserting a filter with new hose would be fine

The hose is probably 10 MM but 3/8" will be fine, just be sure there is some sort of barb on what you are trying to clamp to.

Some crimped hose fittings don't have a barb and rely on the crimped sleeve to hold the hose OD and steel tube OD together. In this case, use a tapered drift to flare the end out a bit and possibly use 2 clamps to distribute the load. Be sure to dress any sharp OD edge so the hose does not cut from the inside.

For steel tube with some space, I use 1/2 of the first step of a double flare or a partial ISO bubble flare to make a barb.

I'd expect a fuel filter to have too fine an element and possibly not stand up to hot ATF very well.

Zulfiqar, not sure which screws you are talking about really for using super extentions?
I have a 2 stage trans lift /jack so no problem here.
I'll remove the clutch fan in front of the engine in case the engine moves with the trans removed, need to hold that engine in place with some 2x 4s?

Martin

I'll use ethanol for flushing the cooler today. I will flush from the passenger side against the normal ATF flow direction (primary pump output is on the driver side?) . I'll catch the output and see with a magnet if any metal chips are in there.
I'll try to do a second flush with kleenguard transmission flush...maybe snake oil but who knows.

Martin

Update: I was flushing this cooler today for hours... very nasty procedure. I used 4 liters of Ethanol and 1 can of the trans cleaner that was recommended.

I flushed maybe 50 times with a bottle for A/C flush and used tons of shop air.
In the end I had not chips any more. I flushed from passenger side to driver side first, then the other way and did it again.
I am pretty certain there are no chip coming out any more but that does not mean there are no chips in any more....at least there are less chips.
I was thinking to add a new filter but what concerns me most is the fact that the cooler has so much resistance... I used 10-12 bar shop air in order to push fluid through this cooler... Can it be that there is such resistance or is this cooler clogged?

I mean the cooler is not holding air pressure but it takes some while until it gets through
This is probably my biggest concern right now. Is there a measurement to check if that cooler has not too much resistance?

I'll send pictures later

Martin

You used 140 + PSI? That's a lot of pressure and likely more effectively more volume even considering air is less viscus than oil. This could make things feel high resistance

The return side of the cooler only feeds lube circuits in the trans so flow won't be huge.

Most / all trans have a internal to trans cooler bypass in case the cooler lines get pinched off, lube oil will still flow.

Your trans is the slightly larger version of this guys, have a look at his info.

http://www.peachparts.com/shopforum/tech-help/388156-help-1995-722-424-transmission-troubleshooting-after-rebuild.html

97, thanks,

I read through this... but did not find a conclusion if the working pressures are
too low per specs and If yes...why they are so low.
If too low then either the pump is worn or a leak somewhere else with the pressure escaping.

Is there not a pressure regulator somewhere that sets the pressure no matter if the transmission is hot or cold?

Too bad that this thread is not continuous coming to conclusions and a positive result.

Martin

97, yes I used 150psi air pressure that gets bogged down some at the Schrader valve in the Flush Bottle . Pictures are attached.
I flushed the hell out of that cooler and I got lots of chips removed...
As there is not guarantee that there are more chips coming out some day I decided to order and install an new radiator... The risk is simply too high.
I also could add another transmission filter ... but I am very unsure why the resistance of the cooler is so high and I have no means to know if this is per design or if that cooler is clogged. So I decided to bite the bullet and get a new Behr radiator.

What I don't understand... if chips are in the cooler the chips must have been 'produced' or picked up after the trans filter and before the cooler.

Is this a hint to what was eaten up in this transmission? (I would very much like to know and understand that transmission better and what happened)

Another concern is that the chips might have damaged the transmission more that I was aware of. As the chips land in the pan at some point what is on the way between cooler and pan? I mean is there an understanding where there can be no chips? Or could these chips be found basically anywhere inside the transmission including valve body? If chips got into the valve body I'd be amazed because they would have changed the nature and behavior of the transmission radically...
Do you think chip got into the valve body?
And if yes... what could they do?

Martin


Ah.. that magnet (screw driver hanging from there) should probably stay there at all my pan.... but heck if the chip is in the pan the filter will catch it anyhow...so why bother with a magnet...

The cooler could be packed with chips tightly enough that they restrict flow and won't come out. Cleaning coolers 100% is difficult if not impossible. The have lots of small passages so the oil is exposed to may surface area for better cooling, this is what traps the chips.

The ATSG manual ( that you have correct? :) ) will show a hydraulic diagram. Oil flows from pan, to filter, to front pump, to line pressure regulator, to torque converter pressure regulator, to torque converter, to cooler inlet, to cooler outlet, to gear train lube circuit.

If anything after the filter but before the cooler comes apart, it will end up in the cooler.

It is also possible for something past the valve body to come apart then, as that friction element is released, contaminated fluid is sent back to the valve body. Generally shops don't science this king of thing out and clean / replace parts as needed.

If your trans filter is designed with a bypass valve, this would let dirty fluid flow. Bypass valves open when oil is too thick to flow through the filter. The "dirty" oil in a normally operating transmission is less damaging than starving for oil. The filter is mostly there for fine material that causes long term wear.

The type of chip is more helpful than the location. Fine gray is cast iron, soft silvery flakes are bushing material, hard thin silver flakes are bearing / hardened shaft material, dark soft crushable flakes are friction material.

Chips in the valve body can hang valves making for erratic shifting / slipping. Puling the valve body apart is the best way to clean. It is very time consuming and could take as long as the trans rebuild it's self.

The magnet will remove slowly produced fine steel particles that otherwise can pass through the filter and cause long term wear. If the material isn't magnetic, the pan magnet won't pick it up. Also, the fluid must pass by the magnet in order for chips to be picked up. There is lots of fluid splashing around but not much magnet area so fluid might not pass by the magnet for a few cycles. ( RE, the trans is making metal at a faster rate than the magnet can pick it up. )

For some reason MB does not install a magnet on the 722.6 introduced in 1996, this is odd for a trans listed as no fluid changed needed for the life of the trans. They were probably counting on a super fine filter taking care of this.

Thanks 97,

Possibly clogged trans heat exchanger:
Yes I think you are right and I will order a new radiator, the only clean way out of this.


Type of chips I found in the pan and filter: the big ones are shiny roundish shaped steel chips 1mm-2mm. They are shiny if you look at certain angles with a headlamp and they appear greyish in other angles but definetely steel and magnetic. This means this can be: "soft silvery flakes are bushing material [..if steel], hard thin silver flakes are bearing / hardened shaft material" .

Can this also chopped up springs? I have found one piece of spring in the pan...at least it could be a spring. Pictures of what I found attached.


Not sure how to identify the filter...how does the bypass filter look like vs the non bypass filter?

This means that steel chips can go through the transmission possibly various cycles and clog the cooler + damage wherever they get stuck...very evil.

If the chips damaged the bearings and shafts... I guess the old transmission is beyond repair?

"The ATSG manual ( that you have correct? ) will show a hydraulic diagram. Oil flows from pan, to filter, to front pump, to line pressure regulator, to torque converter pressure regulator, to torque converter, to cooler inlet, to cooler outlet, to gear train lube circuit."

I have the ATSG manual but did not see the hydraulic diagram yet... my had 108 pages..what page might that diagram live?

Fact is there are lots of chips found in the cooler: this means they will possibly not make it beyond the cooler (well I could flush the hell out of it and I got chips also when I flushed on direction AFT flows (driver to passenger side)
At least the findings in the cooler means that damage/wear must have happened before the cooler: front pump/line pressure regulator/torque converter pressure regulator/torque converter/cooler....
meaning after the cooler (assuming that chips did not easily pass the cooler) the valve body and planetary gears were not affected?
However as there were chips also in the filter either the chips could pass through the cooler or there was damaging wear also beyond the cooler.

I'll see when I am taking the old transmission apart.

How great are chances that I can rebuild the old damaged transmission? .... or is it a safer bet to now rebuild the used replacement transmission I have found on ebay and is in my garage (150K, no chips in the pan... rubber relatively soft)
I intended to install the donor trans fast just to get the car back on the road after resealing and maybe some other checks and changes you'd recommend before it goes into the car? (I have the Precision banner kit here to exchange seals and frictions).

I had various smaller problems with the damaged trans but nothing super alarming: It shifted always..all gears.. It was sometimes not shifting correctly as it should (when I tried to correct the cable/control pressure...but that was not it...
Or in the end the trans was shifting hard (it banged the gears) and I thought the modulator vacuum was disconnected but it was not and modulator worked well.

"Chips in the valve body can hang valves making for erratic shifting / slipping. Puling the valve body apart is the best way to clean. It is very time consuming and could take as long as the trans rebuild it's self. "

Could chips in the valve body explain the hard shifts I had in the end?

Thanks for all the information.

Martin

Bushings are generally made with a steel backing and a Babbitt wear surface ( Tin/ lead ish metal ) Babbitt isn't magnetic so only in advanced stages will the steel backing wear out. Sometimes bushings are bronze or even use needle bearings rather than bushings. Generally at least the front pump is a bushing. I don't recall what this trans has.

Springs are hard and will generally retain a wire profile even if chopped up a bit, pic 2 could be part of a light weight spring.


You would have to cut it open and look for a spring loaded valve / area where the element will flex and bypass the filter.


Any trans can be "repaired" by swapping enough parts but it comes to a point where not much of the original trans is left. Given you have a replacement trans, I'd end up rebuilding / reconditioning the new one then swapping it out.

Another possibility is to remove the original trans, take it apart using it as a learning tool then work on the new trans.


I don't have this manual, a good diagram will have different colors calling out different pressures / control circuits and diagrams specific for shifter position and what gear the trans is in. Try this link ( click around the site to bring up pictures )

GEARS Magazine - December 1999

some diagrams
GEARS Magazine - December 1999

GEARS Magazine - December 1999


Chips will make their way through the cooler, that is why shops install an aftermarket filter on cooler outlets when there is lots of metal.



If you are pressed for time, doing a quick recondition on the new one and installing it is an option. At this point it might last as long as you have the car.




Yes, if a pressure regulation valve sticks, pressure will go high and shifts will be hard. ( Line pressure goes high when more throttle is applied, this allows the trans to transmit more torque with out damaging it's self. Line pressure is reduced at light throttle to prevent a bumpy shift. )

Thanks a lot 97

I think that your are right... I should rebuild the better unit (the new donor trans) but my time constraints don't allow for this option.
So I decided to get the donor trans a good as possible fast...
Maybe not much is mission. The rubber seems fairly soft at the new trans but I'd probably open up a bit and sniff around but not too deep.
Would you recommend to seal the primary pump and pull the B3 discs/frictions? I heard that I should reduce the 20 springs B3 (from 20 to 15 springs)have you heard about reducing the springs?


My goal is to have the donor trans seals from the outside fast so I don't have to deal with it (if the trans proves to be solid). When the car is back on the road I'll take the damaged transmission apart and try to see what happened.

Thanks for the "GEARS Magazine - December 1999" article and diagrams. This is maybe the best information I have seen so far.
Just so you know the ATSG book is a bad copy in black and white and I looked again and there is no diagram that shows the oil flow really... nothing in color for sure. I hope I bought the right thing here.


I think I'll be happy to get the new donor transmission back in the car as good as possible relative to time.
I then have more time to explore the damaged transmission.

Best, Martin

Hi 97, I checked again the $30 ATSG Manual but there is nothing that reminds me to a useful pressure diagram... no color, no pressure diagram... or do I miss something?

Unfortunately the very interesting information from GEARS Magazine - December 1999 has very small pictures (below 200kB). No way to zoom in.
Do you know where higher res pictures might live?

Martin

I received the new radiator... the 'resistance' inside the ATF heat exchangers is almost identical.... wow.
At least the new one gives me piece of mind.

Martin

Try the direct diagram links I posted then ( on most browsers ) use CTRL and + to zoom in or on the browser menu bar look for a zoom function. The links do not have a built in zoom function.

I got these links from the article so there are more in there.

I'm surprised the ATSG doesn't have a diagram.

Type 722.3 hydraulic diagram in to google then click on images, there are some diagrams floating around there.