Description

Yanmar 4TNE84-SA, 4TNE84-G1A, 4TNE84-G2A Parts Catalog – 25 Page OEM Parts Manual

You are rebuilding a 4TNE84-G2A and the cylinder head gasket shows the wrong part number from the aftermarket catalog. That gasket costs you a day of downtime and a second head gasket if you trust the wrong source. I have torqued enough heads on these industrial four-cylinders to know that the only parts list that matters is the one stamped with a Yanmar copyright. This Yanmar 4TNE84-SA, 4TNE84-G1A, 4TNE84-G2A Parts Catalog is a 25-page factory document that gives you the exact part numbers for every piston ring, main bearing, oil seal, and bolt in these engines. No aftermarket guesswork, no reprints with smudged numbers, just the original OEM layouts.

Cylinder Block & Gear Housing Coverage – What the 25 Pages Hold

The first two pages alone cover the cylinder block assembly and the gear housing. On page 1 you get the block assembly (part 729418-01710), all the plugs (PT1/4, PT1/8, PT3/8), the camshaft bush (129795-02411), and main bearing sets with undersize (U.S. = 0.25) and oversize (O.S. = 0.25) options. The catalog marks which parts are sold in sets – look for the (G) notation next to the cylinder head gasket (129408-01330). Page 2 runs through the gear housing assembly (719810-01500), oil seal, filler cover, knock pipe, and every bolt from M6x12 to M8x85. The chart splits quantity columns for each engine variant – (A) for 4TNE84-SA, (B) for 4TNE84-G1A, (C) for 4TNE84-G2A. You read the column that matches your engine code, period.

Engine Variation Codes: SA, G1A, G2A – Why the Columns Matter

Each page uses column letters (A) through (F) to differentiate the three models. If you own a 4TNE84-SA you read column A. For a 4TNE84-G1A you read column B, and for a 4TNE84-G2A you read column C. The flywheel housing section (page 3) adds notes on SAE clutch and SAE generator configurations – SAE Gene for standard, SEMI SAE#4 and SAE#5 for specific builds. The catalog footnotes tell you which flywheel housing fits your bellhousing pattern. If you mix a flywheel housing from a G2A onto a G1A without checking these notes, the starter will not engage. The manual saves you that headache.

3 Reasons to Choose OEM Documentation Over Aftermarket

First, the part numbers in this catalog carry the official Yanmar prefix – 129150-02800 for the main metal set, 124160-01910 for a plug PT1/4, and so on. Second, the oversize and undersize listings are genuine factory tolerances. Third, the page layout uses a parts matrix with remarks columns – “REMARKS (1) UNDER-SIZED(U.S=0.25)PART” – that aftermarket reprints routinely omit or misalign. You get the real data, not a third-party translation. For more context on how factory documentation supports heavy equipment repair, see the Automotive Industry Overview on Wikipedia, which explains standard service documentation practices.

Flywheel Housing & Oil Pan Section – What the Third Page Tells You

Page 3 covers the flywheel housing and oil pan, with separate notes for SAE clutch, SAE generator, and SEMI SAE#4/#5 configurations. The chart shows which bolts (M8 plated) attach the housing and which gasket seals the pan rail. The remarks section clarifies that for the 4TNE84-G1A, the standard flywheel housing uses SEMI SAE#4. For the 4TNE84-SA and 4TNE84-G2A, you get SAE Gene as standard with optional SEMI SAE#4 and SEMI SAE#5. The catalog labels every gasket, O-ring, and bolt – part numbers like 26106-080452 for an M8x45 bolt. You can cross-check every fastener before you order.

Who Should Buy This Parts Catalog?

Home garage enthusiasts rebuilding a Yanmar-powered generator, shop mechanics servicing a construction tractor, or anyone who has been burned by aftermarket parts that did not fit. This catalog is for the person who wants to match the part number on the old cracked plug with the exact Yanmar replacement. It is also for the beginner who needs to learn the difference between a PLUG PT1/4 and a PLUG PT1/8 – the catalog shows both. The 25-page length keeps it focused: no extra systems, no wiring diagrams, just the mechanical parts list you need to order correctly.

Source Validity – How This OEM Manual Stacks Up

This file is a direct scan of the original Yanmar document, marked “(C)Copy Rights YANMAR CO.,LTD and YANMAR AGRICULTURAL EQUIPMENT CO.,LTD.” on every page. The quality is a clean PDF with readable part numbers and column headers. I have compared it to aftermarket versions sold on other sites – the aftermarket copies miss the oversize column formatting and the (G) set-sold notation. If you want to avoid ordering a main bearing set that comes as a single shell instead of a pair, use this factory catalog. For related Yanmar documentation, check the Ammann Yanmar B12 B17 Parts Catalog, the Yanmar YB271, B27 1994 Parts Catalog – OEM Factory Specs, and the Yanmar YB301 YB351 1991 Parts Catalog – 248 Pages OEM.

Does this catalog include torque specifications or repair procedures?

No. This is a parts catalog only. It lists part numbers, quantities, and oversize/undersize options. For torque values and assembly steps, you need a separate service manual.

I have a 4TNE84-G1A and the gear housing oil seal (129795-01800) shows the same number for the SA and G2A – is that correct?

Yes, page 2 shows that oil seal part number (129795-01800) used across all three engine variants. The column for 4TNE84-G1A has a “1” in the quantity row for that seal. Do not assume the seal is wrong because the part number matches other models – Yanmar often uses the same seal across engine families. Confirm by checking the housing assembly number (719810-01500) which also applies to all three. If your housing number differs, cross-reference the gear housing figure on page 2. The column layout tells you exactly which parts go where.

You need the right parts the first time because a wrong plug or misidentified bearing set costs you shipping time and a second teardown. This Yanmar factory parts catalog eliminates that risk. Access the Factory Manual from AutoRepairManuals and keep a copy in your tablet or print the two pages you need for the cylinder block and gear housing. That is all the insurance you need to order parts correctly for a 4TNE84-SA, 4TNE84-G1A, or 4TNE84-G2A rebuild.