Description

Mercedes-benz 722.6, W5A 580, W5A 400, W5A 330, W5A 300 2004 Service Manual

Pulling the 722.6 out of a Mercedes-Benz truck or car without factory specs? You will be chasing burnt clutches inside a week. I’ve rebuilt enough of these five-speed electronic units to know that aftermarket data gets the clutch pack clearance wrong. This manual—93 pages, published 2004 by ATSG—gives you the original OEM-level information for the Mercedes-benz 722.6, W5A 580, W5A 400, W5A 330, W5A 300 2004 Service Manual. It covers identification, gear ratios, clutch stack-up charts, and the park lock linkage. No shortcuts.

Transmission Identification: Know Your Unit

Page 3 of this manual walks you through how to tell the difference between a W5A 580 and a W5A 400 by looking at the bellhousing bolt pattern and the torque converter hub length. Each variant—722.6, W5A 300, W5A 330—has different clutch counts and apply piston diameters. Mixing them up during a rebuild guarantees a soft reverse or a 2-3 flare. You need the letter codes stamped on the pan rail. This manual lists every variation used behind diesel, 4-, 6-, 8-, and 12-cylinder engines.

Gear Ratios and Clutch Pack Stack-Up: Page 9 Charts

Inside pages 9 and 10 you get the exact clutch pack stack-up charts for each transmission variant. These aren’t generic thicknesses. The manual tells you the number of clutch plates and steel plates per pack, the wave plate position, and the required clearance. Set the B1 brake pack too tight and you get a harsh 4-5 upshift. Page 9 has the numbers you need. Gear ratio information on page 8 shows the sun gear and planetary tooth counts so you can verify you have the correct unit before ordering parts.

Fluid Specs and Maintenance Schedule

Using the wrong fluid in a 722.6 kills the valve body. This manual specifies the factory-fill 236.10 or 236.12 fluid, capacity in quarts, and the exact procedure for checking the level at operating temperature. It also details the torque converter drain plug location and the required bolt torque. No guessing. The park lock interlock linkage on page 11 is frequently overlooked; a misadjusted PLIL can leave the transmission locked in park even after the solenoid releases. Adjust it per the page 11 spec—0.040-inch pin clearance.

Does This Manual Cover the W5A 400 or W5A 330?

Yes. The index lists all five variants: 722.6, W5A 580, W5A 400, W5A 330, W5A 300. Each has its own gear ratio table and clutch pack stack-up. If you are rebuilding a 2004 Mercedes-Benz truck transmission, you need to confirm which torque capacity range you have. The W5A 580 handles higher torque than the W5A 400. This manual tells you which parts interchange and which do not. Using a W5A 330 planetary gear set in a W5A 580 housing will cause clearance issues. The data is right there.

3 Critical Areas This Manual Addresses

Number one: the Electronic Transmission Controller (ETC) interaction with the shift solenoid resistance values—the manual gives you the ohm readings for each solenoid. Number two: the converter clutch apply sequence and the required line pressure at idle. Number three: the factory torque converter bolts spec in ft-lbs, not Newton-meters shoehorned into a conversion chart. Torque those bolts to spec and you won’t see converter walk.

Park Lock Interlock Linkage: A Common Failure Point

The PLIL section on page 11 covers the adjustment procedure using a 1/8-inch drill bit as a feeler gauge. I have seen three shops in San Antonio misadjust this linkage and then blame the shift cable. The manual’s procedure includes a spring tension check and the locking pawl engagement angle. Follow it and you eliminate one of the most common diagnostics rabbit holes.

Why Factory Data Beats Aftermarket Documentation

Aftermarket manuals often pull torque values from generic databases or older model years. This ATSG publication uses OEM-sourced data from Mercedes-Benz engineering releases. The clutch pack stack-up charts came from original factory build sheets. If you rely on a reprint or a third-party CD, you risk using a clearance spec for a W5A 330 on a W5A 580. That is a call-back waiting to happen. This manual is a direct copy of the ATSG training booklet used by transmission shops across North America. You get the same information a pro rebuilder uses.

Who Should Use This Manual

Home garage guys who plan to bench-rebuild a 722.6. Fleet mechanics maintaining Mercedes-Benz trucks. Even experienced transmission techs who want the clutch clearance numbers in one place. The manual assumes you know how to disassemble a transmission—it does not hold your hand through removing the valve body. But it gives you the specs you cannot fake: gear ratios, clutch stack heights, torque converter bolt torque, and line pressure test ports. You also get the fluid fill capacity in quarts for each variant.

You will find the ATSG manual more reliable than aftermarket CDs. If you are also working on other Mercedes-Benz vehicles, check the Mercedes-benz Zetros 2008 Service Manual – Factory OEM Specs for heavy-duty off-road systems or the Mercedes-benz M 157 AMG 2010 Service Manual – Factory OEM Specs for performance engine management. For commercial chassis, the Mercedes-Benz Actros Model 963 2011 Service Manual covers the long-haul drivetrain. External resources on Manual Transmission fundamentals and Manual Transmission theory can supplement your knowledge, but for the 722.6 stick to factory data. Access the Factory Manual and keep it open on your bench.