Description

Chrysler A604 Service Manual – 88 Pages of Factory-Approved Data

If you’re tearing into a Chrysler A604 transaxle without the factory spec sheet, you’re playing roulette with a computer-controlled unit that has zero bands and zero freewheel devices. I’ve seen guys throw parts at these things for days because they chased a code without knowing the oil flow path. This Chrysler A604 Service Manual – 88 pages of data compiled with Chrysler’s own illustrations – gives you the sequence you need to avoid turning that transaxle into a boat anchor. Every page was built from the same material Chrysler sent to dealers, not some third-party rewrite.

Before you drop the pan, pull the Service Manual open. The diagnosis section on page 10 lists each fault code and the specific electrical checks to run. You don’t guess solenoid resistance here – you match it to the chart. That alone has saved me three hours on a 1991 Caravan. Pair this manual with the Chrysler A604 Transaxle ATSG Service Manual if you need the companion data for the same unit in a slightly different layout.

Chrysler A604 Service Manual: 88 Pages of Factory-Approved Data

This isn’t a reprint of some generic transmission textbook. The 88 pages come from the Automatic Transmission Service Group (ATSG) with direct cooperation from Chrysler Corporation. They used the OEM engineering drawings and fluid flow schematics. You’ll find the exact line pressures, torque converter stall speeds, and clutch pack clearances that Chrysler specified for the A604. Page 78 holds the specifications chapter – final drive ratios, spring tensions, and seal cross-sections. Don’t trust a forum post for that data.

Diagnosis Tests – What Fault Codes Mean for Your A604

Starting on page 10, the diagnosis tests chapter walks you through the seven test modes the onboard computer uses. You’ll learn how to read the fault codes without a scan tool – just a voltmeter and the pin-out diagram in the manual. One common failure: the transmission defaults to second speed and reverse when the computer loses the input speed sensor signal. The book tells you exactly which resistance value to check at the solenoid pack. I’ve fixed two transaxles following that single test.

Valve Body Teardown: Pagexa041 Detailed Procedure

The Valve Body section (page 41) is where most techs get in trouble. The A604 uses seven solenoids and a complex channel plate. The manual shows the exact order to remove the valve body bolts – three different lengths, and if you mix them up you’ll strip the aluminum case. There’s a warning about the check‑balls: two have different diameters. Miss one and you’ll get a shudder on the 2‑3 shift. I’ve used this procedure on a 1993 Voyager and it took forty minutes start to finish.

7 Systems Covered in the Specifications Chapter

Page 78 lists seven groups of specs: fluid capacities, line pressures at each gear, torque converter end play, clutch pack clearance, spring free lengths, solenoid resistance, and final drive gear ratios. Each spec is given in Imperial units – psi, in‑lbs, ft‑lbs. The manual also includes the torque values for the valve body bolts (109 in‑lbs) and the pan bolts (165 in‑lbs). That’s the difference between a leaky pan and a dry workbench.

Don’t Skip the Adjust Vents Procedure

Starting on page 33, the “Adjust Vents” chapter covers an often‑ignored step: setting the throttle valve cable and the vent valve clearance. If the vent valve isn’t adjusted correctly, the transmission can overheat and vent fluid through the filler tube. The manual gives you the measurement in inches and the tool required – a 0.080‑inch feeler gauge. I’ve seen DIYers skip this because they thought it was for emissions. It’s not. It keeps the A604 alive past 100,000 miles.

For other Chrysler models, check the Chrysler Stealth 1993 Service Manual – 1286 Pages Factory OEM if you need the full factory set for a Mitsubishi‑based powertrain. If you want a concise reference for the same year, the Chrysler Stealth 1993 Service Manual – 434-Page OEM Factory Specs covers the basics without the extras.

This manual works with a standard socket set, a torque wrench that reads in‑lbs, and a digital multimeter. You don’t need a scan tool for the basic diagnosis. For a refresher on how a traditional Manual Transmission works, that’s a different world – the A604 is all computer logic and hydraulic pressure. But understanding the fundamentals helps you appreciate why this Manual Transmission chapter in the history books is replaced by electronics here.

FAQ

Can I use this manual for the A604 in a 1990 Dodge Caravan?

Yes, this manual covers all A604 variants from 1989 to 1995 across Chrysler, Dodge, and Plymouth models.

What tools do I need to follow the valve body procedure?

You’ll need a ¼‑inch drive torque wrench (in‑lbs), a set of Torx bits (T20, T25, T30), a small pry bar, and a digital multimeter. The manual lists required tools at the start of each section, but the valve body removal specifically calls for a 5.5mm socket for the solenoid screws and a 10mm for the pan bolts. Don’t skip the inch‑pound torque wrench – the valve body bolts spec at 109 in‑lbs, and going over that will crush the gasket and cause cross‑leaks. I’ve seen three shops ruin valve bodies by using a ⅜‑inch drive torque wrench that couldn’t read that low. Buy a dedicated ¼‑inch drive unit that starts at 20 in‑lbs. Also pick up a set of picks for the o‑rings on the solenoids – the manual shows the orientation so you don’t pinch them.

You’ve got the specs, the diagrams, and the factory sequence. Access the Factory Manual and get that A604 back on the road without the guesswork.