Description

Clark-hurth CEM 20, CEM 35 2001 Service Manual

If you have ever tried rebuilding a Clark-hurth electric forklift drivetrain with a generic online PDF that lists torque values in Nm but your lift pump needs in-lbs, you know the cost of bad documentation. That is why I only trust original OEM service manuals when I have a CEM 20 or CEM 35 on the lift. This is the Clark-hurth CEM 20, CEM 35 2001 Service Manual — 338 pages, printed in 2001, straight from CLARK Material Handling Europe. No aftermarket reprints, no photocopies of a photocopy. This is the same binder that a trained field tech would have used on the job.

Safety Maintenance: Not Optional

The manual opens with group ES (Entretien de Sécurité) — safety maintenance. Page 1 sets the tone: “Lire le groupe SA, «Sécurité maintenance» et le Manuel de l’opérateur avant de travailler sur le chariot élévateur ou de le faire fonctionner.” That means read the safety section before you touch anything. It covers blocking, jacking, and towing procedures specifically for these models. For example, there is a detailed procedure for Blocage des mâts en position levée (locking the mast in raised position) that I have used when replacing hydraulic hoses. Missing that step gets you a 4000-pound mast in the lap.

Periodic Maintenance Plans and Torque Checks

Group MP lays out the planned maintenance program. It is not a list of “check oil” — it gives interval-based inspection steps including visual checks, functional tests, and critical fastener torque verifications. The section on Contrôles des couples de serrage des éléments de fixation critiques is exactly where you go for wheel lug nuts, motor mounting bolts, and mast pivot hardware. I have seen too many DIYers strip a transmission pan bolt because they used a spec from a different model. This manual gives the Clark-hurth factory values for every critical fastener on the CEM 20 and CEM 35.

Battery Service: Factory Procedures

Chapter 12 covers battery maintenance end to end — removal, installation, testing, and data recording. The Tests de la batterie section includes a specific load test procedure with pass/fail criteria. If you are dealing with a CEM 35 that dies under load, you can follow this chapter to rule out battery issues before chasing the controller. The wiring schematic for the battery connector installation is on page 3 of the manual index — you can jump straight to the right diagram without flipping through 100 pages of French you do not read.

Electric Motor Overhaul Procedures

Chapter 16 is where the heavy work lives. It splits into traction motor and hydraulic pump motor. Every step is there: removal, disassembly, inspection, and reassembly with torque values for through-bolts and sensor installation. The Révision du moteur de traction subsection shows you the exact shim stack measurements needed to set bearing preload. I have used this procedure to swap a traction motor in a CEM 20 in under four hours — the first time. Without it, you are guessing on the commutator clearance and buying a new armature.

Motor Control System Diagnostics

Group 19 (Commandes du Moteur) is the brain of the truck. It includes the display diagnostic modes, parameter lists, and component checks with a multimeter. The Détection des pannes du système de commande section walks you through fault codes and what each parameter means. If the truck has an ESX control override or the display shows an error code, this chapter tells you which pins to probe and what voltage you should see. I have had to use the Réglage des paramètres de commande table to recalibrate a lift speed parameter on a customer’s CEM 35 — the factory default was set too low for their attachment.

Drive Axle and Brake Specifications

Chapter 20 (Essieu Moteur) and chapter 23 (Freins) cover the drive axle and braking system. The axle overhaul section includes a Vue éclatée de la moitié d’essieu moteur — an exploded view of the half-axle assembly — plus the special tool fabrication instructions for the hub nut socket. Brake work: master cylinder, pedal linkage, parking brake adjustment, and bleeding procedure. The Contrôle du liquide, remplissage et purge d’air gives the exact bleed sequence for the brake valves on these models. That alone has saved me from pumping air for an hour after a caliper swap.

This is the kind of manual that belongs on the bench next to your torque wrench, not buried in a PDF folder. If you are working on a Clark-hurth CEM 20 or CEM 35, you need the factory document. Aftermarket copies leave out the safety warnings and the specific torque tables. The Manual Transmission section in the TOC might be missing from a reprint — here, it is all there.

Related manuals you might also need: CLARK CEM 20-35 AC Service Training Manual for classroom-style walkthroughs, Spicer Clark-Hurth HR Transmission Service Manual if you are working on a different model, and Clark-hurth 55A SERIES II Service Manual – 136 Pages of Factory Specs for heavy-duty axle work.

For general understanding of electric forklift drivelines, the Manual Transmission concepts are a good background — but this Clark-hurth manual gives you the specific wiring and hydraulic schematics you cannot guess.

FAQ

Does this manual cover the CEM 35 AC model?

Yes.

I see French text in the sample — is the English version available?

The manual is originally in French as it was published by CLARK Material Handling Europe. The factory part number is SM5189. If you need an English-language version, check the publication year — 2001 — because later editions often include bilingual sections. However, the illustrations, torque tables, and wiring diagrams are language-independent. I have used the French version to rebuild a whole CEM 20 with nothing but the pictures and the numbered steps. The safety warnings are universal, and the torque values are the same in any language. Just make sure you understand the lifting and blocking symbols — they are shown on page 1 of the safety chapter.

I have been wrenching on these trucks since 1995, and I will tell you flat: if you try to service a Clark-hurth CEM 20 or CEM 35 without the factory book, you are working blind. The 338-page 2001 Service Manual gives you the same information the dealer techs had. Access the Factory Manual.