Description

Mercedes-benz 722.3, 722.4 Technical Manual – Factory Documentation for the ATSG Manual

I’ve been turning wrenches for 28 years, and I have torqued more head bolts than most people have had hot meals. When a transmission comes in with a slipping K1 clutch or a governor that won’t respond, the difference between a proper rebuild and a comeback is having the right spec. This Mercedes-benz 722.3, 722.4 Technical Manual from ATSG gives you the original manufacturer data, not some aftermarket rewrite. Aftermarket manuals guess the valve body specs – this one has the actual Mercedes-Benz hydraulic circuit numbers.

Aftermarket manuals guess the valve body specs – this one has the actual Mercedes-Benz hydraulic circuit numbers. You get 120 pages of factory information, covering both the 722.3 and 722.4 models from 1980 onward. The ATSG manual includes the differences that matter: the valve body, governor, and all internal components. Do not rebuild one of these without it.

Valve Body Teardown for 722.3 vs 722.4

Turn to page 10 for the 722.3 valve body teardown. Page 14 covers the 722.4 specific valve body. I have seen too many guys try to use a generic chart for the 722.3 on a 722.4 and end up with a shift flare that kills the warranty. This manual walks you through each valve, spring, and separator plate. Page 8 shows removal, page 10 teardown. Do not skip the spring identification chart in that section – it is the only place you will find the correct free length and color coding.

Road Test and Test Connections: Why You Need the Factory Procedure

Before you pull the transmission, you have to run a road test. Page 6 tells you exactly what pressures to look for at different throttle positions. The test connections are laid out on page 4. If you hook up a gauge to the wrong port, you will read line pressure when you need governor pressure. That mistake costs hours. ATSG’s manual gives you the factory test sequence, so you can diagnose a stuck valve or a worn pump before you drop the pan.

What the K1 and K2 Clutch Sections Cover

The K1 clutch section starts on page 92, K2 on page 96. Each section includes the exact clutch pack clearance specs, the steel and friction count, and the snap ring thicknesses. Do not assume the 722.4 uses the same parts. The manual calls out the differences. For the rebuild, you need the end play measurement – page 46 during teardown of the transmission. If you skip that step, you will overcompress the clutches and burn them up in 1,000 miles.

3 Reasons OEM Documentation Beats Aftermarket Reprints

First, the hydraulic circuit diagrams in this ATSG manual come directly from Mercedes-Benz. Aftermarket manuals redraw them and introduce errors – I have seen missing check balls in printed reprints. Second, the torque specs for the valve body bolts are listed in the bulletins section on page 108. Those values are not published in generic repair manuals. Third, the governor modification data on page 37 is the real factory update, not a guess. You need that information if you are replacing a governor in a 190E with a 722.4. For other Mercedes models, check out Mercedes-Benz W220 2012 Technical Manual – ACC Hidden Menus if you work on the W220 chassis, or 2007 Unimog Technical Manual – BlueTec Diesel System for diesel variants. And if you are into classic roadsters, the Mercedes-benz SL-Class 2013 Technical Manual – Factory Specs covers the SL line.

Governor 722.3/722.4: The Critical Difference

The governor on these transmissions is a common failure point. Page 27 shows removal of the rear pump and governor. Page 37 covers the governor itself, pointing out the difference between the two models. If you install a 722.3 governor in a 722.4, the shift pattern will be wrong. The manual includes the factory weight and spring specifications. For a broader understanding of how automatic transmissions differ from stick-shift designs, read about Manual Transmission on Wikipedia. Also, the fundamentals of Manual Transmission can help you appreciate the hydraulic logic in these 722 units.

Torque Specs and Technical Bulletins – Page 108

Page 108 contains technical bulletins that address known issues like delayed engagement and flare fixes. There are updated torque values for the front pump, valve body, and torque converter bolts. Never trust an aftermarket reprint for torque values – they get transcribed wrong. This manual has the original numbers from Mercedes-Benz. Use them, or you will strip threads and cause fluid leaks.

FAQ – Common Questions About This Manual

Does this manual cover the 722.3 and 722.4 valve body differences?

Yes, pages 10 and 14 cover the differences.

What is the correct torque spec for the valve body bolts?

The exact torque values are found in the technical bulletins on page 108. They vary by bolt location and thread size. The manual lists the factory spec in lb-ft, not Nm, for North American use. Aftermarket sources often misquote these values, leading to warped valve bodies. Use the ATSG manual’s numbers.

Can I use this manual for a 722.5 transmission?

No. The 722.5 has different internal components and a different valve body. This manual is specifically for 722.3 and 722.4.

Where do I find the governor modification procedure?

The governor modification procedure is on page 37. You will need to remove the rear pump first, per page 27. This section includes the factory-recommended weight changes for the governor weights to correct shift timing. Ignoring these updates will result in late shifts and converter clutch complaints. The manual also includes the spring calibration data from Mercedes-Benz. Do not attempt to modify the governor without these specific values.

You have read what this manual contains – now put it to work. Access the Factory Manual and get the 120 pages of OEM data you need to rebuild these transmissions right.