Help with my 722.1 Series M-B transmission!

[Samuel M. Ross]

A WebSite known to this Forum for transmission parts [ http://www.bulkpart.com ] has an ad that reads:
=======================
Technical manual, 722.0 / 722.1 / 722.2
Code: 58400 // Price: $16.50 - ATSG manual, Disassembly, inspection and assembly sections. Diagnosis, testing and lot of pictures
===========================
What I’m looking for is a greater understanding of the internals of this tranny so I can maybe come up with my own “K-1” that is also know on this Forum… the kit that has helped many resolve shifting problems on their 722.3/722.4/722.5 trannies.

Q1 – Does ANYone have ANY experience with ANY of the series of technical manuals from this vendor?

Q2 – What does “ATSG” stand for… Automatic Transmission Sxx?xx Guide………?

ANY help will be greatly appreciated by me and the old 1980 300D !
Sam

[jbaj007]

See the post in your thread in Diesel Discussion.

I've got the ATSG (Automatic Transmission Service Group) manual for 722.3/722.4 and find it useful; not perfect, but useful.

[Samuel M. Ross]

Thanks “ jbaj007 ” for your input… for I have ordered the “Technical manual, 722.0 / 722.1 / 722.2 ” from: http://www.bulkpart.com .

If any of you have followed the several threads on these now infamous “ K-1 kits ”, then you probably know of: http://transmission.articles.mbz.org/k1/ which is titled:

The K1 Kit Page 2/3 Upshift Flare Repair
This is a fix for transmission slip/flare on 2-3 upshift
at partial load for 722.3,722.4 and 722.5 automatic transmission

And there was also a subsequent post that included the 7 photos that were/are missing from the article… and also included 8 short steps for installing this kit.
This post was titled
“K1 ACCUMULATOR SPRING KIT FOR 722.3-722.4-722.5… P/N 126_270_44_77 ”.

I have gleaned additional information from:
(a) http://www.bulkpart.com, and one of their sources for automatic transmission parts
(b) http://www.transmissionkits.com

Based upon what I have at this time I think I can state:

(1) The M-B K1 [ K-1] kit [ p/n 126_270_44_77 ] could probably also be described as a
“Clutch Piston Retainer Repair Kit” which is what (b) calls their similar but expanded "K-1/K-2".
(2) The full title of (b)’s kit is “K-1, K-2 Clutch Piston Retainer Repair Kit” and I have found
nothing indicating that it is sold by (a) despite their distribution of other of (b)’s products.
I also note that this K-1/K-2 kit is only for 722.3 and 722.4 series transmissions… NOT for the 722.5.
(3) The 722.3 transmission has a 6-bolt pan used on 1981-97 model M-B(s).
(4) The 722.4 transmission has a 6-bolt pan used on 1984-97 model M-B(s).
(5) The 722.0, 722.1, & 722.2 transmissions were 4-bolt pan transmissions used on 1970-83 M-B(s).
(6) Considering that the 722.5 was a newer design 5-speed tranny, there is a good chance M-B’s K-1
Kit might not work on this transmission which was on 1990-97 M-B(s).
(7) In addition to the above expanded K-1/K-2 kit for the M-B 722.3 & 722.4 trannies,
“Precision International” [ (b) above] markets a number of products for M-B transmissions, some of
these through (a). For example they have 3-levels of kits for the 722.0 through 722.4 that range in
cost from $105 to $168 through (a)… and it looks like you can purchase directly from (b) as well
but you have to call… and supposedly (b) offers “ FREE ” technical support at their toll-free phone
line.

Having stated the above, it’s beginning to look dim that I will come up with some kind of K-1 kit for these earlier model M-B’s tranny series [ 722.0-722.1-722.2]… but I have not given up yet. I’m also pressing M-B[USA] corporate for information so keep your fingers crossed and pass along any clues you might have out there.

Sam

[Samuel M. Ross]

OK, here is my update:
I just got off the M-B [USA] Classic Parts hotline with "Tom". They have a limit of 1 subject/per call and clearly are under pressure to move on to the next CUSTOMER! So I gave "Tome" the M-B p/n we all know [ 126_270_44_77] and asked him what he could tell me about it. He stated that the only name his "system" gave him was "AMG". I think this clue ["AMG"] is a dead end... but if you have broadband and like hi-performance stuff, take a look at http://www.mercedes-amg.com/!

I then asked if he could give me the individual p/n(s) that went into the kit. He did, and here they are.

The K-1 Kit, p/n 126_270_44_77] for the 722.3 and 722.4 is made up of:
126_277_41_77
126_277_42_77
126_993_58_04
126_993_59_04
126_993_60_04

So there you have it, more clues to this puzzle... and armed with these, I'm back to the local dealer's parts counter to see what names, if any they can give me for these parts! On my last trip there they gave me 3 different parts blow-up diagrams from their reference for my 722.1 tranny... you know the diagrams that comes from the thick, old catalogs like mine [(Mod. 123) CATALOG "F"] with tons of blow-up diagrams for the entire car.

Well apparently M-B is now up to "K" [mine is "F"] in their computer-based references. My "F" catalog has 9 pages of diagrams for the 722.1 tranny and sure enough the 3 pages my dealer gave me did not include the page I think will be needed for my 722.1 K-1 sleuthing.
Wish me luck!
Sam

[Samuel M. Ross]

A brief recap is in order. The “ K-1 Kit ” [ p/n 126_270_44_77 ] is well know on this forum and is an official M-B kit of 3 springs and 2 plastic rods onto which the springs mount inside a plastic piston [not in the kit ]. There are excellent pictures in the archives showing how to remove the old and install these new parts. As best I can tell, this kit is for the 6-bolt pan 722.3 and 722.4 series transmissions that I believe were installed in 1981-97 model M-B(s). The kit is officially M-B called “ Druckstift ” which literally translates to “ pressure pin ”. On the kit packaging it is labeled in English as “ Thrust Pin… Unit ”. On this forum it is said that this kit is primarily to correct 2-to-3 shift problems only.

Results of my sleuthing

(1) From M-B Sources - I have been trying to find a K-1 kit equivalent for the earlier 722.1 / 722.2 transmissions… more specifically the 722.118 in my Son’s 1980 300D[na] M-B. I purchased the 126_270_44_77 kit to have as a reference [and as future parts for my in-law’s 85 300SD]… and M-B USA corporate in N.J. identified the p/n(s) for the 5 parts in the kit. These p/n(s) are of little use as my local M-B parts counter canNOT reference the p/n(s) on their official M-B parts computer system! I’m continuing to try with my dealer’s to identify these same/equivalent parts in the 722.1 / 722.2 series trannies. I have repeatedly been stymied by M-B USA corporate when I ask for this information from their “Classic Parts” department!??

(2) Other Sources - I have purchased the “ATSG; Mercedes 722.1 / 722.2 TechTran Manual ”. For me, the best thing about having this manual are the numerous diagrams… and from these diagrams and what little I have gleaned from M-B, I would say that clearly the K-1 kit installs in what we have come to know as the “Valve Body” that is readily accessible after the pan and filter are removed. From the ATSG manual I have learned that valve body is also more descriptively known as the “Shift Valve Housing”. From this same manual’s diagrams, my best estimate is that the 3 springs in the 126_270_44_77 kit are comparable to the 722.1 / 722.2 transmission springs that are descriptively called:
(1) Weak Spring Pressure Absorber B1 / K1 / K2 ,
(2) Strong Spring Pressure Absorber B1 / K1 / K2 , and
(3) Piston Spring Pressure Absorber B1 / K1 / K2 .
I found NO comparable parts for the two plastic “thingies” in the K-1 kit that the springs are mount on in the 722.3 / 722.4 tranies.

At TransmissionKits.Com there is a parts listing in Precision International’s [PI] aftermarket catalog where I found a much more descriptive name for what this K-1 kit might/should be called… “ Clutch Piston Retainer Repair Kit ” and PI has separate kits for the 722.3 and 722.4 trannies that address both K-1 and K-2 and yes.

Finally at BulkPart.Com I have found a K-1/K-2 springs only kits [“ Valve Body Kits ”] for the 722.3 / 722.4 transmissions and what’s interesting here is that there are separate kits… one for gas fueled engines and one for diesel!

That’s where I’m at for now. Hopefully soon someone at M-B will come through for me and identify the 3 springs in the 722.118 tranny that are equivalent to the 3 springs in the M-B kit for the 722.3 / 722.4.

Let me point out that it was this forum and your posts that gave me the initial clues… M-B has given up very little information and this somewhat grudgingly [I'll bet that's no surprise to many of you!] …
so thank you for the clues,
I hope to close this thread out soooooon !
Sam

[C32AMG]

The Clutch Piston Retainer Repair Kit, are use for the drum piston retainer seals in the K1 and K2 clutch drums. Try this test as it may answer your questions, remove the steel Accumulator cover on the valve body, replace the two inner springs with the single long heavy spring found in the 722.3 K1 kit. Road test the car cautiously, I am guessing, all the up shifts should be firm.

[Samuel M. Ross]

To state it here again as I think you meant to say it :
========================================
The Clutch Piston Retainer Repair Kit(s), are used for
the drum piston retainer seals in the K1 and K2 clutch drums.
Try this test as it may answer your questions:
(1) remove the steel Accumulator cover on the valve body,
(2) replace the two inner springs with the single long heavy
spring found in the 722.3 K1 kit, and
(3) Road test the car cautiously.
I am guessing, all the up shifts should be firm."
=====================================
Q - In (2) above are you saying to use the large spring in the:
(a) M-B 722.3/722.4 kit or
(b) the Precision Int'l K1/K2 kit for the 722.3...
[which is it (a) or (b)?] to replace the two springs
[the "weak" spring that fits inside the "strong" spring ]...
replace both of these with the single spring from the kit?
A little confused,
Sam

[brewtoo]

Originally Posted by Samuel M. Ross

And there was also a subsequent post that included the 7 photos that were/are missing from the article… and also included 8 short steps for installing this kit.
This post was titled
“K1 ACCUMULATOR SPRING KIT FOR 722.3-722.4-722.5… P/N 126_270_44_77 ”.

Sam

I am unable to find this post. Where is it?

Thanks

[C32AMG]

At TransmissionKits.Com there is a parts listing in Precision International’s [PI] aftermarket catalog where I found a much more descriptive name for what this K-1 kit might/should be called… “ Clutch Piston Retainer Repair Kit ” and PI has separate kits for the 722.3 and 722.4 trannies that address both K-1 and K-2 and yes.



The Clutch Piston Retainer Repair Kit mention above, are only used when rebuilding the transmission, they are an internal kit, for the drum piston retainer seals in the K1 and K2 clutch drums, inside of the transmission.






Try this test as it may answer your questions, remove the steel Accumulator cover on your valve body the only steel plate with three bolts, remove the first spring then the steel piston, once the steel piston is removed you will find two springs behind it.

Remove those two inner springs and replace them with the single long heavy spring found in the 722.3 K1 kit # 126 270 44 77. Road test the car cautiously, I am guessing, all the up shifts should be firm. And might cure your 2nd to 3rd flare.


Adjusting the modulator and the control pressure rods will achieve the same as above, if the valve body is not worn or damage. See below.

The 722.0, 722.1, 722.2 valve bodies use steel check balls in them to control, divert oil, these balls do damage to the valve body and aluminum housing and plate. It’s a common problem with the early transmission.

[Samuel M. Ross]

back there in NY. I'm impressed with your extensive past posts on trannies!

I know I want to try something to revive this 722.118 tranny before giving it up to some rebuilder as a "core"... so I'll definitely file your suggested "test" on my short list of possibilities. I'm just not ready to rush into swapping parts between two different model trannies as well as leaving one of the old springs out altogether! That's a bit radical to be my first choice to try! Maybe later it will look better if nothing else develops!

You do call your recommendation a "test"... so does that mean there would be alternative actions afterwards depending upon how the "test" goes... or would I just leave it that way if there was enough improvement over what we have now ? Right now I have my Son pretty well trained to shift manually... and even how to use 2nd gear with a manual shift without it flaring until well above 25mph! So with this trick we are able to use all 4 gears and manually accellerate quite well! So we can use the car quite well as it is!

But I still think that M-B's reason for their K-1 kit for the 722.3/722.4 series was because of design problems... and it is entirely likely that the later trannies in the 722.1/722.2 series might very well have the same design flaw.

If the new spring parts are not too expensive, I'm game to give that a try, even if M-B's Classic Parts people never come through for me. Right now I'm asking my local M-B parts counter if they have a parts blow-up diagram for the valve body [aka "shift housing] so we can proceed to I.D. these springs in the 722.118.
Regards,
Sam

[Samuel M. Ross]

I almost forgot to give you this update:

Update #4… I have found a great WebSite for vintage M-B tranny information [ vacuum diagrams and parts diagrams]. I knew about this previously but didn’t think to bring it to your attention. This is a regional/local transmission rebuilder who also has a retail shop just down the street from their rebuilding operation in Redwood City, CA. They are also a “ Factory Authorized ‘ ZF ’ Distributor ” for trannies/parts imported from Europe. "ZF" is apparently a major German rebuilder for high-end European autos.

Their WebSite’s Home Page is at http://peterschmid.com/ … and when you go there be sure to take a look in the left margin where there are links for the following :
(1) Parts Diagrams [ blowups ],
(2) Application Guide [ for knowing what trannies were in what models ],
(3) Vacuum Schematics [ outstanding… broken down into several year/model categories ],
(4) Tech Tips [ cable control adjustments for 103, 104, 119, 119.79, 120, and 603 engines ]
(5) Vacuum Control Valve tests [ 7 pages for 123 & 126 model trannies from a M-B manual ]

The best engine/tranny vacuum diagram I have found for my 1980 300D [California edition] came from (3) above on this WebSite.

Still pushing M-B [Corp & Local] for answers… but progress is slooooowwwww!
Sam

[Samuel M. Ross]

Well it looks like I have run into a stone wall with M-B!
Unless one is prepared to purchase either:
(1) a major transmission rebuild kit, or
(2) a complete new “valve body” [aka “shift housing”]
it does not appear that M-B is much help to me in my quest to try to come up with my own low cost K-1 kit for these earlier trannies.
Yes, I know some of you are saying that “I told you so” !

So this leaves me one final gasp to save my K-1 kit idea and this is based upon a suggestion by “C32AMG” who must have nightmares about these auto trannies or maybe he just worked most of his adult life in or owned a transmission shop and worked on a lot of these early trannies.

In any event, as soon as I finish working on another family car and make room in the garage, I will be dropping the pan on the 1980 300D’s tranny and remove the 3 springs and piston that make up what I now believe are collectively referred to as the “Accumulator ” section of the tranny’s
“Upper Body ”. This is reachable just by dropping the pan.

Once I have removed the 3 springs and piston, I will side-by-side compare them to those in M-B’s K-1 kit for the 722.3/722.4 trannies.
At that point I will have to decide on whether to install one or more of these updated springs in the my 722.118 tranny! So I will put it back together, fire her up and take it for a ride!

Of course I will report back to all of you who wait with "baited breath" or maybe more likely by now wishing I’d put this dead horse out of its pain!
Regards,
Sam

[C32AMG]

Originally Posted by Samuel M. Ross

back there in NY. I'm impressed with your extensive past posts on trannies!


You do call your recommendation a "test"... so does that mean there would be alternative actions afterwards depending upon how the "test" goes... or would I just leave it that way if there was enough improvement over what we have now ? Right now I have my Son pretty well trained to shift manually... and even how to use 2nd gear with a manual shift without it flaring until well above 25mph! So with this trick we are able to use all 4 gears and manually accellerate quite well! So we can use the car quite well as it is!

But I still think that M-B's reason for their K-1 kit for the 722.3/722.4 series was because of design problems... and it is entirely likely that the later trannies in the 722.1/722.2 series might very well have the same design flaw.
Sam

Quote:this is based upon a suggestion by “C32AMG” who must have nightmares about these auto trannies or maybe he just worked most of his adult life in or owned a transmission shop and worked on a lot of these early trannies.




If its works leave the springs in. The use of a pressure gauge is the right way to diagnose this problem, verifying correct modulator and working pressures, low pressures can cause shift over lap problems = flare up shifts

The K1 kits were made to compensate for normal ware and tare in the valve body. The K1 kit are about $12.






Thanks for the link, I am always looking for technical information, especially if it make my job easier. I am familiar with ZF transmissions, my first ZF rebuilt was a ZF 3HP 22 in a Peugeot.

I have been rebuilding transmissions, transfer cases and differentials for 30 + years and still counting, I have owned my transmission shop for many years and still rebuilt every day. Good competent reliable help is hard to find. At 53 years old I still love working on cars.

Good luck.

[Samuel M. Ross]

Well I finally got around to dropping the pan off my 1980 300D's 722.118 tranny and found that one has to also remove the entire valve body [aka "shift housing" ] to get at the same springs and piston parts that come in the "K1 Kit" that M-B sells for their 722.3/722.4 trannies [ p/n 126 270 44 77 ]. So I canNOT say if any of these parts from this kit will also fit/work in my 722.1 transmission. Removing the valve body to get at these same parts on the 722.1 tranny was just too daunting a bit of backyard surgery for me to consider on a tranny that just turned 300K miles. So it looks like a new tranny with a 2-year warranty [PeterSchmid.com] and installed by my local independent M-B 1-man shop...~$2,300 !

Sam

[rkpatt]

Your posts here are very informative. I would have liked to hear aboout your rebuild but I understand that your frustration and leaving it to the shop . I am about to buy a 1983 300sd which is not shifting right . I want to take on a DIY rebuild although my one only experince has been a Ford C-4 20 years ago .