Description

Clark-hurth 40, 45, 50S 1999 Service Manual – Factory Specs on the Bench

I’ve been wrenching for 28 years and seen more hacked-together repairs than I can count—usually because some guy grabbed a generic manual or a third-party PDF that had the wrong torque values. If you’re pulling wrenches on a Clark-hurth 40, 45, or 50S forklift from 1999, the difference between a solid rebuild and a come-back job is in the specs. This Clark-hurth 40, 45, 50S 1999 Service Manual is the exact 332-page document Clark dealerships used. It’s not a reprint, not a scan with missing pages—it’s the original SM-648, revision 1, July 1999, and it’s the only thing I trust for those Perkins engine internals and transaxle work.

Let me walk you through what’s inside and why you want this on your iPad or printed out next to the lift.

Safe Maintenance – Group SA

Group SA covers safety, lifting, jacking, blocking, and towing. Before you crack a single bolt, read Section 1. Lifting a 10,000-lb machine wrong gets people killed. The manual gives you the exact blocking points and jacking procedures—stuff aftermarket books skip. Section 2 goes into lifting and blocking with diagrams. Section 3 on towing tells you what to disconnect so you don’t wreck the driveline. I’ve seen a $6K transaxle grenade because some guy forgot to pull a driveshaft. Don’t be that guy.

Periodic Service – The PM Form and Critical Fastener Torque Checks

The Periodic Service section (pages are grouped under Group PER) includes a full Planned Maintenance Program. You get a service chart with lubrication points, a recommended schedule, and the actual PM form used by dealerships. The Basic PM Procedures list includes visual inspection, functional tests, stall test, cranking voltage test—and the one that causes 90% of comebacks: Critical Fastener Torque Checks. If you’re rebuilding a mast or replacing a steer cylinder, those torque values are in the PM section. Don’t guess.

Engine Group 00 – Perkins Workshop Manual (Recommended Torque Tensions)

Group 00 is the whole Perkins engine service manual—over 150 pages. It’s broken into subsections: cylinder head assembly, pistons and connecting rods, crankshaft assembly, timing case, cylinder block, fuel systems (CAV and rotary pumps), lubrication, cooling, flywheel, electrical, and power steering pump. The Specifications sub-section lists “Recommended torque tensions” for every fastener. Example: cylinder head bolts—page 00-1-? (the manual uses Group-Section-Page IDs like 00-1-2). If you’re rebuilding a Perkins 4-cyl or 6-cyl from a 50S, you need the exact torque sequence and values. Aftermarket manuals either copy these wrong or leave them out. This is the real deal.

I especially appreciate the “Data and dimensions” tables. Cylinder head assembly data, main bearing clearances, piston ring gaps—all in imperial units. No metric-conversion guesswork. The manual even includes the list of special tools for the engine, which saves you from buying tools you don’t need.

Transaxle, Hydraulic System, and Electrical – Factory Diagnostics

Group 25/26 (Steer System), Group 29/30 (Hydraulic System), Group 21/22 (Transaxle), Group 50 (Electrical), and Group 60 (Brakes) are all in this manual. The Transaxle section covers fluid level check, overhaul procedures, and troubleshooting. The Hydraulic System includes pump overhaul and control valve overhaul. The Electrical section has the full circuit diagram and instrument pod details. If you’re chasing an intermittent electrical fault on a 40 or 45, you need the factory wiring diagram, not a generic schematic. This manual has it.

Source Validity – Why OEM Matters More Than Your Budget

I’ve been burned by aftermarket manuals that claimed “factory specs” but had the wrong torque for the steering unit. This manual is a genuine Clark Material Handling Company publication—copyright 1999, intended for CLARK dealers. It’s ISO 9001 certified. The PDF is a direct scan of the original dealer binder. There’s no guessing when you read “Torque to 155 ft-lb (210 N·m)” because it came from the same document the factory techs used. If you work on lift trucks for a living, you know that using aftermarket specs on a 50S can cause mast failures or brake drag. Do it right once.

Audience Fit – Who Should Buy This

This manual is for anyone who owns, maintains, or repairs a Clark CMP 40, 45, or 50S forklift built around 1999. That means shop owners who want their techs to stop wasting time, DIY mechanics who refuse to pay dealer labor fees, and fleet managers who need a consistent reference for 10 identical trucks. If you’ve got a Perkins diesel engine, this covers it. If you’ve got the hydraulic pump from a 45, this covers it. If you’ve got a transaxle that’s leaking, you need the disassembly sequence here. It’s 332 pages of hard data—no filler.

One more thing: if you’re also working on older Clark models, check out the Spicer Clark-hurth HR Service Manual – Factory Specs for Heavy-Duty Transmission”> or the Clark-hurth 55A SERIES II Service Manual – 136 Pages of Factory Specs”>. For a more recent machine, the Clark-hurth SM-715, TMX12-25, EPX16-20s 2007 Service Manual – 502 Page OEM Facto”> covers later models.

For background on how a Manual Transmission”> works, or how manual transmissions differ from hydrostatic drives, Manual Transmission”> is useful context, but the spec you need for a 50S is right here.

FAQ – Two Questions I Get About This Manual

Does this manual cover the CAV fuel injection pump timing?

Yes. Group 00 has a subsection “Engines fitted with CAV fuel injection pumps” that includes instructions for setting #1 piston to TDC on compression, checking valve timing, and checking the timing mark of the fuel injection pump. The procedure is from the Perkins workshop manual—not a generic guide.

Does it include torque values for the transaxle?

It includes the transaxle overhaul procedure with critical fastener torques listed in the Group 21/22 specifications. You won’t find them in a third-party book.

Look, I’m not here to sell you a PDF you’ll never use. I’m here because I know what happens when you work with wrong specs. If you’ve got a Clark 40, 45, or 50S that landed in your shop, get the factory data. Access the Factory Manual.