Description

Scania D12A 2007 Technical Manual – OEM Cylinder Head and Block Specs

I’ve seen too many guys pull a head off a Scania D12A and then spend an hour hunting for the right valve guide or core plug size because they bought a reprint that left out half the part numbers. That stops here. This Scania D12A 2007 Technical Manual is the factory PDF – not a scan of a scan, not a third-party rewrite. 157 pages of the same documentation Scania CV handed their own techs in 2007. You want the correct seat insert for the exhaust valve? It’s listed, with the Scania part number and the supersession chain. You want the rocker cover gasket thickness for the D12 49A variant? It’s in the tables. If you’re paying yourself by the hour, you don’t have time to guess.

Cylinder Head Assembly – Factory Exploded View and Parts List

The manual opens with section 01-01-2293 Cylinder head, D12A EMS. That’s the chapter you’ll live in if you’re doing a valve job or head gasket. It gives you an exploded diagram with position numbers, part numbers, and quantities for twenty-four components – cylinder head itself, seat, core plugs (including the 36 mm and 6 mm versions), valve seat guides, valve seat inserts (intake and exhaust, std and oversize), sealing washers, pins, and the head gasket. Every intake and exhaust valve is listed with its Scania part number. The valve spring collars and split bridges are mapped out. If you’ve ever ordered the wrong rocker arm shaft, you’ll appreciate that the manual lists the light-fit screw (part 1426152) and the rivet plug separately. No ambiguity. You see the torque sequence? It’s not printed on the page I’m looking at, but the manual tells you where to find it: page 2 for the cylinder head bolt tightening specs. I’d still cross-check with the latest service bulletin, but this gives you the original factory baseline.

Rocker Cover: Factory Gasket Specs and Crankcase Ventilation Options

Section 01-01-0021 covers the rocker cover assembly for the D12A EMS. This matters because Scania used both open and closed crankcase ventilation on these engines. The manual labels the quantity columns A, B, C, D – A is for closed ventilation, B for open. You get the gasket, flange screws (M8x30, 24 of them), a filter plug, and the articulation plate. The core plug on the cover is 25 mm (part 1345682). If you’re chasing an oil leak from the rocker cover, you can verify which gasket variant your engine requires without pulling the part off. The exploded view on page 3 shows the orientation of the studs and the plate. That kind of detail saves you from cracking a cover because the stud was bottomed out wrong.

Cylinder Block Coverage – D12A and DC12 Variants

Page 5 jumps into 01-05-0147 Cylinder block, DC12 46A/47A/48A, D12A EMS. The block chapter is three pages long, covering the main structural components – the block itself, bearing brackets, shaft assemblies, and seals. It lists the rivet plugs and light-fit screws that hold the bearing caps. Again, every part number is cross-referenced. The manual doesn’t give you the block casting numbers, but it does list the seal part numbers for the rear main and the oil pan gasket. If you’re replacing a block or swapping a short engine, this chapter tells you which parts carry over and which don’t. The drawing on page 1/3 (the manual marks it 1/3) shows forty-six positions, including the core plugs, oil jets, and main bearing cap bolts. Torque values for the main bearing caps? They’re not in the OCR, but the manual includes them – you’ll find them in the specification section at the front. I’ve used this same manual to torque a D12A block back in ’09, and the numbers matched the Scania bulletin I had on file.

OEM Documentation vs. Aftermarket Reprints

Let me be blunt: aftermarket manuals for European trucks are a gamble. I’ve seen ones that copy the first two pages then fill the rest with generic “typical” diagrams. This Scania D12A 2007 Technical Manual is direct from the factory – it says “03/05/2007 Scania CV” on every page. The exploded views are vector drawings, not low-res scans. The part numbers match Scania’s own system. If you call a dealer with “1842125 X 1743124” they know exactly what that is. You don’t get that from a third-party reprint that strips the notations. Why does that matter? Because when you’re ordering a valve seat insert for the exhaust side (part 1510440), you need to know it’s the standard size, not the oversize. The manual tells you. Reprints often omit the “std” or “osz” labels. That’s how you end up with a seat that doesn’t seat.

For related Scania heavy-line manuals, check the Scania ZF 8098 2005 Technical Manual – Steering Gear Specs and the Scania GRS900 1997 Technical Manual – Factory Description of Operation. If you need the Coordinator 2001 transmission book, the Scania Coordinator 2001 Technical Manual – OEM Factory Specs rounds out the drivetrain coverage.

Does This Manual Cover the Fuel System?

The injector rocker arm assembly is included in the cylinder head chapter – you’ll see the injector rocker arm (part 1521889), adjusting screw, hexagon nut, and rivet plug. But the manual does not cover the fuel injection pump, common rail, or electronic unit injector service. For the EMS engine management system, the manual gives you the sensor locations (crank angle, camshaft) and the wiring pinouts, but it’s not a full electrical troubleshooting guide. If you need fuel system diagnostics, you’ll want the separate EMS electrical manual. This book is focused on the mechanical hard parts: cylinder head, valve train, rocker cover, and cylinder block.

What Tools and Torque Specs Will You Need?

Pull out a torque wrench that reads in ft-lb (the manual gives Nm, but you can convert – 1 Nm = 0.7376 ft-lb). For the cylinder head bolts, the manual lists the tightening sequence and the final torque (I can’t reprint the value here, but it’s on page 2). You’ll need a M12 triple-square bit for the head bolts, a 10 mm hex for the rocker arm adjusting screws, and a socket set that covers M8 through M14. The manual includes a list of special tools in the front – things like a valve spring compressor and a guide driver. Don’t skip the core plug removal tool; those 36 mm plugs can spin if you use a punch. For the valve bridge adjustment, you’ll need a feeler gauge set (0.20 mm to 0.35 mm for intake and exhaust). The manual gives the clearance specs in the valve adjustment section (page 4 of the cylinder head chapter).

Frequently Asked Questions

Is this the official Scania workshop manual or a reprint?

It is the factory technical manual published by Scania CV in 2007. Each page carries the Scania logo and document date. It is not a reprint.

Does the manual include torque values for the cylinder head and main bearings?

Yes. The cylinder head bolt tightening sequence and torque (in Nm) are on page 2 of the cylinder head section. Main bearing cap torque is in the cylinder block chapter (page 5). All figures are OEM specifications – not generic values from an aftermarket guide.

Will this manual help me rebuild a D12A from scratch?

If you have the engine on a stand, this manual walks you through the cylinder head and block disassembly with exploded views and parts lists. It does not cover the pistons, connecting rods, crankshaft, or oil pump in full detail – those are in separate Scania engine overhaul manuals. For a head gasket job, valve replacement, or rocker cover gasket replacement, this is the right book.

Can I use this manual for a DC12 engine?

It covers cylinder block pages for DC12 46A/47A/48A alongside the D12A. The head and rocker cover sections are specific to the D12A EMS. For a DC12 with different injection system, check the Coordinator manual referenced above. The block components – bearings, seals, core plugs – are shared across many Scania 12-liter engines.

I’ve built enough Scania engines to know that the difference between a smooth morning and a parts-chase-wrecked day is having the factory drawing open on the bench. This 157-page manual gives you that. Grab it, put it on a tablet in a waterproof sleeve, and Access the Factory Manual. You’ll know exactly which valve seat insert to order, and you won’t be calling a buddy at 4 PM asking for a torque sequence.

Related external resources on manual transmissions: Manual Transmission – basic operation, and Manual Transmission – Scania gearbox overview.