Description

Mitsubishi F4A41, F4A4B, F4A42, W4A42, F4A51 Parts Catalog

I’ve been wrenching for 28 years, and I still see guys order the wrong seal kit because they guessed from a blurry photo on a forum. That mistake eats billable hours and leaves a transmission on the bench. For these Mitsubishi front-wheel-drive four- and five-speed units — the F4A41, F4A4B, F4A42, W4A42, and F4A51 — you need a factory parts breakdown, not a re-drawn aftermarket sketch. This 18-page Parts Catalog came from JP (Automatic Transmissions) Ltd in the UK, but the exploded views and part numbers trace straight back to Mitsubishi’s original spec. Every bush, sprag, clutch drum, and pump stator on page 2 lines up with the correct reference. That’s what you get when you access a genuine OEM document instead of a third-party copy.

Transmission Parts Breakdown – What You See on Page 2

Flip to page 2 of this catalog and you’ll find the full cross-section drawing of the F4A41/F4A4B/F4A42/W4A42/F4A51 family. The exploded view labels items like the rear cover (part 759), the output planet (part 056), the overdrive planet (part 039), the reverse clutch drum (part 140), and the low sprag (part 185). Each component has a numbered callout that matches the kit lists on later pages. If you’ve ever had to hunt down the exact input shaft seal (part 670) or the direct clutch drum (part 344), you know why having the factory diagram saves an hour of cross-referencing. The catalog also breaks down the 5-speed-only parts — check the “5 Speed Only” note near the underdrive drum (part 561). That kind of specificity keeps you from ordering a part that doesn’t fit.

Paper & Rubber Kits – 3Kits Listed for 1996-Up

Page 3 gives you the three main gasket and seal kits. For the F4A41 and F4A42 1996-up, order kit 41000A. For the F4A51 1996-up, it’s 41000B. The F5A51 five-speed (2001-up) takes 41000C. These are factory-designated paper and rubber kits — not a generic assortment. If you mix up 41000A with 41000B, the clutch housing seals won’t match. The catalog lists each kit with the quantity (always 1) and a reference column. That column is blank in the original PDF because it’s meant for your own inventory notes. Smart shop practice: write in the date and mileage when you install a kit.

Overhaul Kits and Master L/Steels Kits

Beyond the basic paper and rubber, the catalog covers overhaul kits (41002A for F4A41/F4A42, 41002B for F4A51/W4A51, 41002C for F5A51) and a Duraprene variant (41002DF). The master L/steels kits — 41004A for the F4A41/F4A42, 41004B for the F4A51/W4A51 — include every friction and steel plate you need for a full rebuild. These kits are transmission-specific, so don’t assume a 1998 F4A42 kit fits a 2003 F4A51. The page 3 table makes the cut clear. For the exact part numbers and kit references, you must have the printed catalog in front of you. Memorizing them from a yellowed photocopy will cost you.

3 Reasons to Use a Factory Parts Catalog Instead of Aftermarket Lists

First, aftermarket catalogs often merge several model years into one diagram, hiding small but critical differences like the low/reverse clutch hub (part 056) variation. Second, the torque converter stator and pump body (parts 500–507) are often mislabeled in third-party parts databases. Third, the supplier information — JP (Automatic Transmissions) Ltd with their direct contact: +44 (0) 1934 852772 and info@jpat.co.uk — means you can verify the document’s lineage. If a part number looks off, you can call them. That’s not possible with a scanned eBay listing.

Who Needs This 18-Page Catalog?

If you rebuild these Mitsubishi transmissions in a home garage or a six-bay shop, this catalog is your minimum buy-in. The DIYer who wants to avoid buying two different input shaft seals because the first one’s ID was wrong — this is your insurance. The professional who charges by the job needs to grab the right kit on the first order. The catalog doesn’t include torque specs or step-by-step rebuild procedures; it’s strictly a parts identification tool. Pair it with a factory service manual for the specific model year, like the Mitsubishi F4A41 F4A42 F4A51 2005 Technical Manual PDF for the assembly instructions, and you’ll have a complete rebuild package. Also check the Mitsubishi S3L2 2009 Parts Catalog – OEM Factory Specs if you work on Mitsubishi industrial engines, or the Mitsubishi S6A3-PTA PTK 1991 Parts Catalog – Factory OEM Specs for marine applications. For broader context on the transmission technology, see the Automotive Industry Overview and the Automotive Battery (yes, battery – because even a transmission shop needs a solid battery for your scan tool).

Does this catalog cover the F4A4B and W4A42 models?

Yes. The title includes F4A4B and W4A42 alongside F4A41, F4A42, and F4A51. The exploded views and kit lists apply to all these variants.

How do I identify which kit is right for my transmission code?

Look at the transmission tag on the bell housing. The model code (e.g., F4A42) and production year (1996-up vs 2001-up) determine the correct paper/rubber kit (41000A, 41000B, or 41000C). The catalog’s tables on page 3 separate them clearly. If the tag is missing, the case castings often have a partial number you can cross-reference with the exploded view on page 2.

Are there any torque values in this document?

No. This is a parts catalog, not a service manual. It lists part numbers, kit contents, and exploded views. For torque specs you need a separate factory service manual, like the F4A41/F4A42 workshop manual.

Is this a reprint of an aftermarket guide?

This is a direct scan of the original JP (Automatic Transmissions) Ltd publication, which uses OEM Mitsubishi data. The header says “MITSUBISHI” and includes the JP copyright. It is not a reprint compiled from third-party sources.

Eighteen pages of factory-correct part numbers, exploded views, and kit cross-references for the Mitsubishi F4A41, F4A4B, F4A42, W4A42, and F4A51 transmissions. I’ve seen too many rebuilds stopped cold because someone ordered the wrong low sprag. Don’t be that guy. Access the Factory Manual and get the parts right the first time.