Description

Clark-hurth 35B Service Manual – What You Get on the Bench

This 79-page factory service manual for the Clark-hurth 35B is the same binder the dealer techs used when these machines were new. If you are a shop owner, a mobile heavy-equipment guy, or a DIY owner-operator running a Michigan 35B Tractor Shovel, you already know what happens when you guess a torque value on a 3-inch transmission bolt. Seized threads, broken housings, and a machine down for days. This manual stops that.

Factory documentation, not aftermarket copies. The sections match the actual build: Torque Converter tear-down and reassembly sequence (page 3), Transmission disassembly (page 11), Disc Brake overhaul (page 29), Main Control Valve rebuild (page 37), Hydraulic Gear Pump service (page 49), and Drive Axle (page 57). Every spec comes from the original Clark-hurth engineering department. No third-party redrawing. No missing pages.

Transmission Overhaul – What the Manual Shows You

Section 2 covers the 35B transmission in full. Disassembly sequence, bearing preload checks, clutch pack clearance tolerances. You get the factory lubrication circuit diagram – no guesswork on which oil passages feed the forward clutch or where to plug test ports. The Transmission section also includes shift linkage adjustment specs. If you have ever had a 35B that won’t hold a gear in third, this is where you find the answer. Need the CLARK 35B Parts Catalog to go with it? That helps if you discover a broken snap ring during teardown.

Torque Converter – Reassembly Sequence Matters

Section 1 walks through the converter from description to after-overhaul test procedure. It tells you the order the stator and turbine go back in – get that wrong, and the pump impeller clearance is off by 0.030 inches. After Overhaul (page 9) lists the leak test pressure and the required stand time before you button it up. Use a click-type torque wrench, not a beam style, for the converter housing bolts. The manual calls for thread locking compound on the impeller retaining nut – and it says which grade.

Does This Manual Cover the Brake System?

Section 3 is the Disc Brake chapter. That is 8 pages of factory procedure: caliper piston removal, rotor runout limits, and pad wear measurement. The Brake system on a 35B uses a wet disc design. The manual gives the torque for the caliper mounting bolts and the banjo fitting that feeds the brake line. If you are dealing with a soft pedal that keeps dropping to the floor, the troubleshooting notes on page 30 point to the shuttle valve inside the main control valve – cross-referencing to Section 4.

Main Control Valve Rebuild – Why You Need Factory Data

Section 4 covers the Valve body that controls all hydraulic functions. Spool clearance, spring free length, and relief valve setting pressure are all listed with OEM tolerances. Aftermarket valve rebuild kits sometimes ship with o-rings that are 0.005 inch undersize. That causes internal leakage and sluggish bucket dump. The manual specifies the exact o-ring cross-section and durometer. You also get the order of disassembly for the detent mechanism – step 7 warns you about a small ball bearing that launches if you pry the spool out too fast. I have seen guys lose that bearing. Then you are ordering a new valve because the replacement kit does not include it.

3 Systems That Rely on Correct Torque

Torque Converter cover bolts. Transmission pan bolts. Disc brake caliper bolts. Hydraulic pump mounting bolts. The manual lists torque values in foot-pounds for every critical fastener. Page numbers in the margins of each section correspond to the torque table. If you are used to working on cars, do not assume SAE threads on a 35B – these are mostly UNC coarse thread, and a few are fine. The manual notes the difference. A torque wrench is non-negotiable here.

Hydraulic Gear Pump – Wear Limits and Shimming

Section 5 is only 8 pages, but it tells you the gear backlash, side clearance, and the two shim packs that control gear depth inside the pump body. If the pump is noisy at high flow, you check the thrust washer thickness against the spec in this section. The manual even shows the preferred direction for the pump before you install it on the engine – the coupling spline alignment is directional.

Source Authenticity – OEM Print vs. Aftermarket PDF

This is a scan of the original Clark-hurth maintenance manual, not a rekeyed copy. That matters because aftermarket reprints often omit the “Cleaning and Inspection” steps or replace them with generic “clean all parts” nonsense. The factory manual tells you what solvent is acceptable for the torque converter stator (mineral spirits, not brake parts cleaner), what grit abrasive to use on the valve spools (320-grit crocus cloth, not sandpaper), and what the dry-plate torque spec is for the transmission clutch discs. You do not get that from a third-party redraw. Want a companion reference? Spicer Clark-hurth HR Service Manual – Factory Specs for Heavy-Duty Transmission covers later-series transmissions but shares some internal geometry. For the smaller 55A series that uses a similar converter, see Clark-hurth 55A SERIES II Service Manual – 136 Pages of Factory Specs.

FAQ

Does the manual show step-by-step disassembly with photos?

Yes. Section 1 uses exploded-view drawings and numbered steps. No generic text.

I have a Michigan 35B with a transmission that slips in forward. Which section do I start with?

Start with Section 2 – Transmission, page 11. Check the clutch clearance spec and the control pressure port test. The manual gives the pressure values for forward, reverse, and low-range clutch engagement. If pressure is low, move to Section 4 – Main Control Valve, because the regulator spool might be stuck. If you skip the pressure test, you will waste time pulling the transmission for nothing. The manual also cross-references the brake dump feature that can bleed pressure into the brake circuit – that is covered in Section 3, page 32. Do not ignore the brake section; I have seen a worn shuttle valve cause a transmission to slip because it sends oil to the brakes instead of the clutch.

When you have the factory specs in front of you, the time you lose flipping pages is less than the time you lose redoing a job because the torque was wrong. This is the manual the Clark-hurth field service reps carried. Access the Factory Manual and keep it on the tablet next to the grease gun. If you need background theory on how a manual transmission works, Manual Transmission at Wikipedia gives a general overview – but for the 35B, you want the OEM data. For a broader understanding of manual gearboxes in heavy equipment, check Manual Transmission on the same site. That is basic theory. The Clark-hurth manual is applied practice.