Description

Mitsubishi Motors F4A41, F4A42, F4A51 2002 Service Manual

If you are tearing down a Mitsubishi Motors F4A41, F4A42, F4A51 2002 Service Manual automatic transmission without the factory book, you are gambling with clearances, spring tensions, and torque values. I have been there. One wrong snap ring or a misread valve body spring and you are pulling the unit again. This 135-page manual from Mitsubishi Motors gives you the exact specifications for the F4A41, F4A42, and F4A51 transmissions. No aftermarket guessing game. The torque specs on page 23A-1-9 are the ones the engineers wrote when the transmission was new. You want that data, not some third-party rewrite.

Torque Specs and Valve Body Spring Data

Page 23A-1-9 lists every torque value for the transmission case bolts, valve body bolts, oil pump fasteners, and more. The VALVE BODY SPRING IDENTIFICATION TABLE on page 23A-1-3 tells you which spring goes where by free length and color. I have seen shops ruin a shift quality by mixing up those springs. Mitsubishi also provides the SNAP RING, SPACER, THRUST WASHER, THRUST RACE AND PRESSURE PLATE FOR ADJUSTMENT chart. That section alone saves you from buying the wrong shim kit. If you need the clutch pack clearance numbers, they are in the SERVICE SPECIFICATIONS. Do not trust a YouTube video for that.

What’s Inside the Transmission Section?

Chapters 3 through 15 walk you through the complete disassembly, inspection, and reassembly. Chapter 3 covers the main transmission removal from the vehicle. Chapter 4 is the oil pump – clearances and rotor tip specs are given. Chapters 5 and 6 break down the underdrive clutch with input shaft and the reverse/overdrive clutch packs. There are separate sections for the planetary carrier depending on whether you have an F4A41 or F4A42 without one-way clutch versus an F4A42 with one-way clutch and the F4A51. That distinction matters. Overdrive planetary carrier (Chapter 7) and planetary carrier assembly (Chapter 7a) are handled separately. The LOW-REVERSE BRAKE (Chapter 8) and SECOND BRAKE (Chapter 9) give you specific plate count and separator spring placement. Output shaft (Chapter 10) and differential (Chapter 12) – all factory procedure. Transfer drive gear is only covered for pre-December 1997 units, so check your build date.

7 Chapters You’ll Use Most

In my shop, these get thumbed to death: Transmission (Chapter 3) for R&R steps, Oil Pump (4), Underdrive Clutch (5), Reverse/Overdrive Clutch (6), Low-Reverse Brake (8), Second Brake (9), and Valve Body (13). The valve body chapter alone has the check ball locations, spring identification, and separator plate thickness. You will also find the Speedometer Gear and Drive Shaft Oil Seal procedures. Every chapter has its own specification table, so you are not flipping back to the front repeatedly for fluid capacities or sealant types – they are listed per unit. The SEALANTS table on page 23A-1-10 tells you exactly which Mitsubishi part number to use on the oil pump gasket and which on the transmission case halves.

Understand the Valve Body Before You Touch It

Chapter 13 is the valve body. If you have ever had a transmission that shifts harsh or slips after a rebuild, nine times out of ten the valve body is the culprit. Mitsubishi includes the VALVE BODY SPRING IDENTIFICATION TABLE with free length and wire diameter. They also list the spring identification colors. Pull a spring out, measure it, and match it. Do not reuse a collapsed spring. The manual also shows the check valve locations and the correct orientation of the separator plate. That plate has tiny orifices – if you mix up the gaskets, you change line pressure. This is not an area for shortcuts.

Factory Service Bulletins: Why They Matter

At the back of the manual, Mitsubishi included four service bulletins: MSB-99E23-002, MSB-99E23-003, MSB-99E23-503, and MSB-00E23-002. These bulletins address known issues like updated clutch pack clearances or revised valve body separator plates. A used transmission from a junkyard might have original parts that superseded by these bulletins. Check them. The bulletin dates are 1999 and 2000, which means they apply to this 2002 manual’s coverage. Ignoring bulletins is like ignoring a recall – you rebuild a transmission with the same flaw that failed originally.

For an overview of automatic transmission principles, see the Automotive Industry Overview”>Automotive Industry Overview for general theory. But for this specific transmission, use the factory book. If you need a manual for the LASER or TALON, check the Mitsubishi Motors LASER TALON 1990 Service Manual”>Mitsubishi Motors LASER TALON 1990 Service Manual. For manual transmission specs, the Mitsubishi Motors R5M3, V5M3 2000 Service Manual – Factory Transmission Specs”>Mitsubishi Motors R5M3, V5M3 2000 Service Manual – Factory Transmission Specs covers those units. And if you want the broader context of manual vs automatic, refer to the Manual Transmission”>Manual Transmission page on Wikipedia.

This manual is for the DIYer who has a solid mechanical background – you know how to use a micrometer and a torque wrench. It is not a textbook on how an automatic works; it assumes you can identify parts. Beginners should still buy it because the torque specs and clearances are the same whether you have rebuilt ten transmissions or one. But if you have never pulled a valve body before, take your time. The Valve Body chapter is detailed, but you need to read it twice. The 135 pages are dense with data – no fluff, no filler. Every page has a purpose. The publication year is 2002, which covers the F4A41, F4A42, and F4A51 transmissions used in Mitsubishi Galant, Eclipse, and other models of that era.

Do not bother with aftermarket manuals that tell you “refer to factory service manual for torque specs.” You already have the factory manual right here. The Automatic Transmission F4A41, F4A42, F4A51 Manual”>Automatic Transmission F4A41, F4A42, F4A51 Manual is the original OEM document scanned from Mitsubishi Motors Corporation. No reprints, no missing pages. The pdf is a direct copy of the printed shop manual used by dealership technicians. The TRANSMISSION MODEL TABLE lists the model codes applicable to specific vehicles, so you can confirm fitment before ordering parts.

FAQ

Does this manual cover the F4A51 transmission?

Yes. The F4A51 is included in the title and throughout the chapters, including planetary carrier assembly section 7a and transfer drive gear notes.

Are the torque specs in ft-lb or in-lb?

Both. The TORQUE SPECIFICATIONS table lists values in Nm and ft-lb/in-lb. For example, oil pump bolts: 11 ± 1 Nm (97 ± 9 in-lb).

What special tools are required for a valve body rebuild?

The manual lists special tools in Chapter 2. You will need a spring scale to measure check valve force, a dial indicator for clutch pack clearance, and the Mitsubishi oil pump alignment tool. Without the dial indicator you cannot set the end play correctly. That tool is part number MB [DATA NEEDED] – the manual shows the equivalent aftermarket cross-references. But if you have the OEM tool, use it. The manual gives you the measurements for a substitute if you cannot get the factory tool.

Do the service bulletins replace any of the manual’s original specs?

One bulletin updates the second brake clutch plate count for certain production ranges. You must follow the bulletin if your transmission serial number falls in the range. The manual’s original specs remain correct for earlier builds, but always check the bulletin before ordering plates.

You need this factory documentation on your bench. Every torque value, every spring length, every bulletin – it is all in one place. Access the Factory Manual now and stop relying on memory or incomplete forums. Your transmission build will be right the first time.