Description

Yanmar 3TN84L-RBA Parts Catalog

If you’ve ever ordered a part for one of these small vertical diesel engines and ended up with a block that doesn’t fit, you know the pain. This is the OEM Yanmar 3TN84L-RBA Parts Catalog – 35 pages of factory-issued part numbers, exploded views, and supersession data. I’ve torqued head bolts on these T-series engines more times than I care to count, and the single biggest time-waster in any rebuild is hunting down the right part. This catalog kills that guesswork cold.

Cylinder block assembly on page 2? You get part number 729157-01560 for the block assembly itself, plus every plug, bolt, bushing, and main metal down to the thrust washer. The exploded diagram shows exactly where the thrust metal #10 goes relative to the camshaft bush #11. No aftermarket catalog bothers with that level of fitment detail – they’ll throw a generic “engine block” at you and call it done.

Cylinder Block Assembly: Part Numbers and Supercessions

Every line in this catalog includes a revision code. Look at the head gasket row: 129157-01332 is the original sxa0tandard gasket, but there’s a separate entry 129157-01333 marked “(NON-ASB.)” with revision flags N, A, TE-93048, E51186. That supersession data is gold – you don’t order the old asbestos gasket when the non‑asbestos replacement is available. The catalog tells you exactly which part replaces which and when the change happened. Ignore that and you’ll be pulling the head again in 500 hours.

Gear Housing and Oil Seals: Critical Fitments

Gear housing assy (719810-01500) comes with its own oil seal (129795-01800) and a blind cover (121023-01550). The catalog lists O-ring sizes: 1A P-16.0 for the injection pump, 1A P-32.0 for the housing. Those are metric JIS sizes – not the same as generic SAE O-rings from the hardware store. Page 4 shows the full housing assembly with eight different bolt lengths from M8x12 to M8x85. If you mix up the M8x45 and M8x55 bolts, the gear housing flange won’t seat square and you’ll get an oil leak that soaks the flywheel.

One thing that jumps out at me in the OCR data – the catalog uses a three‑column numbering system with revision flags like “W”, “*”, “EXXX”, and “R”. That means some parts have superseded versions or alternate suppliers. The “R” flag on the seal washers (22190-080002) indicates a replacement for the earlier 43400-500410. If you’re working on an older 3TN84L-RBA that was built before TE-93179, you need the early washer; after that, use the later one. This catalog saves you from buying the wrong seal washer and having it leak on startup.

What Does a Parts Catalog Actually Do for You?

It’s not a service manual – there are zero torque values or disassembly steps in these 35 pages. What it gives you is the exact factory part number for every nut, bolt, gasket, seal, and casting in the engine. When you’re rebuilding a core that’s been swapped between machines, you need to verify that the cylinder block is the correct variant for your application. The catalog lists the block assy as 729157-01560 with no suffix – if your block has a different number, you’re not working with a true 3TN84L-RBA.

I’ve been burned by aftermarket “OEM equivalent” part lists that claimed a standard head gasket fit all T‑series engines. That’s a lie. The 3TN84L-RBA uses a different gasket thickness than the 3TN84L‑RJ or the 3TN84L‑RB. This catalog shows the exact gasket part number (129157-01333 for non-asbestos) and the correct piston ring set numbers. Ordering blind from an online parts store without these numbers is gambling with your labor time.

7 Assembly Groups Covered

Flip through the 35 pages and you get:

• Cylinder block assembly (page 2)
• Gear housing and oil pump cover (page 4)
• Piston and connecting rod assembly
• Cylinder head and valve train
• Flywheel and housing
• Fuel injection pump and governor
• Lubrication system components

Each group has its own exploded diagram with callouts matching the part number list. That’s the only way to confirm you’re ordering the correct main bearing undersize (US=0.25 or OS=0.25) or the right thrust metal thickness.

OEM vs Aftermarket: Why a Wrong Gasket Costs Double

Aftermarket parts catalogs – the ones you find on third‑party sites – often merge different engine variants into a single list. They’ll show one head gasket for “Yanmar 3TN84” and you’ll get a gasket that’s too thick or too thin. The OEM catalog from Yanmar itself is the only document that separates the 3TN84L-RBA from the 3TN84L-RJ, 3TN84L-RE, and every other suffix. Those suffixes matter because they correspond to different injection timings, different piston crown heights, and different gasket thicknesses. A 0.5mm gasket error kills compression and power.

I’ve watched a shop waste four hours and a set of head bolts because they used an aftermarket “universal” gasket. The water passages didn’t align. They had to pull the head, wait a week for the correct gasket, and re‑torque. That’s a $600 mistake. This catalog lists the exact gasket (129157-01333) and the cylinder head studs (129150-01200) – 14 studs per head, M8x14 or M8x16 bolts depending on revision. No guessing.

FAQ

Does this catalog include torque specifications?

No. This is a parts catalog, not a service manual. Torque specs, clearances, and assembly procedures belong in the factory service manual. Use this catalog to order parts, then follow the service manual for installation.

How do I read the part number columns and revision flags?

Each line has a part number, description, quantity per engine, and a set of revision codes. The “N” flag means the part was added in a later production run; “A” means alternate supplier; “R” means replacement supersedes an earlier number. The superscript numbers (like 1 or 2) after the quantity indicate an optional or oversized version – for example, main metal US=0.25 is listed as a separate line item. Match the flag code to your engine’s serial number range if available.

Need a parts catalog for a different Yanmar variant? Check the related manuals: Ammann Yanmar B12 B17 Parts Catalog, Yanmar YB271, B27 1994 Parts Catalog – OEM Factory Specs, and Yanmar YB301 YB351 1991 Parts Catalog – 248 Pages OEM. For background on how OEM documentation keeps the Automotive Industry Overview running, note that factory data is non‑negotiable. Automotive Industry Overview standards apply here – if you want a job done right, you start with the right part numbers.

Access the Factory Manual and keep a copy on your shop tablet or printed and laminated. It’s 35 pages – small enough to tuck in a tool box cover. When the customer brings in a 3TN84L-RBA with a blown head gasket, pull this catalog, order the non‑asbestos gasket and 14 studs, and get the job done without a second parts run.