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.

__________________
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1995 E300D - The original humming machine (consumed by Flood 2017)
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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.

HELP: 1995 722.424 transmission troubleshooting after rebuild

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...

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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

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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