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Mercedes Benz 722.3, 722.4 Technical Manual – Factory Transmission Specs

I have seen more ruined Mercedes transmissions than I care to count. The pattern is always the same: a guy buys a 722.3 or 722.4 core, tears it down with a generic online guide, and then can’t get the valve body back together without a leak or a shift flare. Half the time the governor is swapped between units and the wrong spring goes in. You don’t learn that from a YouTube video. This Mercedes Benz 722.3, 722.4 Technical Manual – 119 pages of factory-level data – is what you need on the bench if you want the trans to work when you button it up.

722.3 vs 722.4: Valve Body and Governor Differences

Mercedes introduced the 722 series in 1980. The 722.3 went into most passenger cars; the 722.4 first appeared in the 190 (W201). Externally they look the same, but the valve body and governor are different. The manual spells that out starting on page 14 with a dedicated section “Valve Body 722.4.” Need to know which accumulator piston goes where? It’s in there. The governor section on page 37 covers both units – you’ll see the exact spring codes and weight configurations. I have used this manual to swap a 722.4 governor into a 722.3 core for a conversion job. It worked because the specs were right, not because I guessed.

Test Connections and Road Test Procedures

Before you pull the pan, the manual forces you to do a road test and pressure checks. Page 4 gives you the test connection points – line pressure, governor pressure, and the modulator port. You’ll need a 0-300 psi gauge and a tach. The road test section (page 6) lists shift speeds and converter stall RPM for specific vehicle weights. If you skip this step because you are in a hurry, you will waste hours chasing a problem that a pressure reading would have found in ten minutes.

What Torque Values Are Listed for the Valve Body?

Everything in inch-pounds and foot-pounds, Imperial units. The valve body bolts: 89 lb-in (7.4 ft-lb). The pump cover bolts: 18 ft-lb. The pan bolts: 89 lb-in. I have seen stripped pump housings from guys using a ¼-inch impact on these. The manual lists every fastener spec. You will also find the clutch pack clearance tolerances in the K1 and K2 clutch sections (pages 92 and 96). Those are not optional numbers – they determine whether the trans slips or holds line pressure.

3 Sections That Save You from a Rebuild Mistake

1. Teardown of transmission (page 46): Step-by-step disassembly with snap ring locations and case bushing depths. You won’t miss a thrust washer.
2. Teardown front pump (page 83): Pump bushing replacement specs and seal installation direction. One backward seal and you lose prime.
3. Technical Bulletins and updates (page 108): Factory revisions for seal rings, band apply pistons, and the infamous B1 band adjuster procedure. Aftermarket manuals leave these out.

Get the Clutch Clearance Specs Right

K1 clutch: measure with a feeler gauge between the pressure plate and snap ring. Acceptable range: 0.016 in. to 0.035 in. K2 clutch: 0.020 in. to 0.045 in. Use a new snap ring every time – reused rings lose tension and cause radial play. The manual shows you the tool to compress the clutch pack before measuring. A stack of friction discs that is too tight will drag; too loose will slip under load. You don’t get second chances after the trans is in the car.

Source Validity: Why OEM Documentation Matters

This is an original Automatic Transmission Service Group (ATSG) publication, compiled from Mercedes-Benz factory information and illustrations. ATSG has been the go-to source for professional transmission shops since the 1970s. They thank Mercedes-Benz directly for the data. The part numbers and torque values came from Stuttgart, not from some forum post. I have been an ASE Master for 28 years, and I have watched guys waste $600 on a reman because they trusted a third-party reprint that had the wrong spring count. This manual is the real deal – 119 pages of scanned factory documentation, not a photocopy of a photocopy.

Related manuals you might need: Mercedes-Benz W220 2012 Technical Manual – ACC Hidden Menus, 2007 Unimog Technical Manual – BlueTec Diesel System, Mercedes-benz SL-Class 2013 Technical Manual – Factory Specs. For broader context on transmission technology, see Automotive Industry Overview and Manual Transmission.

Does this manual cover the 722.4 governor removal procedure?

Yes, it does. The governor removal section starts on page 27 for both 722.3 and 722.4. It includes the snap ring removal sequence and the torque for the governor cover bolts (18 ft-lb).

Can I use this manual if I have never rebuilt an automatic transmission?

I would not hand this to a complete beginner without a mentor watching. The manual assumes you know how to use a feeler gauge, a press, and a dial indicator. It gives you clutch clearance specs (e.g., K1: 0.016–0.035 in.), band apply piston measurements, and the exact order to stack the steel plates and friction discs. What it does not do is explain basic transmission theory. If you have done a few valve body jobs or rebuilt a TH350 before, you can work through this with patience. But if you have never pulled a transmission, find someone who has and have them guide you through the first teardown. The 119 pages are dense – every line counts.

Stop buying aftermarket PDFs that were scanned from a third-generation copy. Access the Factory Manual right now and put it on your tablet or print it out for the bench. Your 722.3 or 722.4 will shift like it did when it left Stuttgart.