Introduction
This document provides detailed service information for the Danfoss OSPM steering unit, covering its components, spare parts, required tools, and step-by-step procedures for dismantling and assembly. It is intended for service technicians and maintenance personnel.
Revision History
| Date | Changed | Rev |
|---|---|---|
| Mar 2014 | Converted to Danfoss layout - DITA CMS | BA |
| Feb 1998 | First edition | AA |
Exploded View
The exploded view diagram illustrates the internal components of the OSPM steering unit, showing how each part fits together. It serves as a visual guide for assembly and disassembly. Components are identified by numbers corresponding to the spare parts list. Key components include:
- 1: Dust seal ring
- 2: Housing spool and sleeve
- 3: Ball
- 4: Ball stop
- 5: Shaft seal
- 6: Distributor plate
- 7: Bearing
- 10: Ring
- 11: Cross pin
- 12: Set of springs
- 13: Cardan shaft
- 14: Spacer
- 15: O-ring
- 16: Distributor plate
- 17: Gearwheel set
- 18: O-ring
- 19: End cover
- 20: O-ring
- 22: Special screw, incl. O-ring
- 23: Special screw, incl. O-ring
- 24: Name plate
- 30: Complete relief valve
- 31: Spring for relief valve
- 37: Ball
Note: A torque specification of 30 Nm is indicated for certain screws.
Spare Part List
| Item | Spare parts | Dimension | Code no. | Comments | Number per unit |
|---|---|---|---|---|---|
| 1 | Dust seal ring | 26 x 19 x 4 | 150L0396 | Integrated column | 1 |
| 2 | Housing spool and sleeve | (not sold separately) | 1 | ||
| 3 | Ball | Ø3/16" | 689X1005 | 1 | |
| 4 | Ball stop | 29 | 150L0462 | ON with check valve in P-port, item 37 | 1 |
| 42 | 150L0463 | PB with check valvein P-port, item 37 | 1 | ||
| 34 | 150L0464 | ON + PB, without check calve in P-port | 1 | ||
| 5 | Shaft seal | 21,9 x 17,5 x 3,1 | 150L0411 | 1 | |
| 23,4 x 19 x 3 | 150L0412 | Integrated column | 1 | ||
| 7 | Bearing | 150L4046 | 1 | ||
| 10 | Ring | 150L0380 | 1 | ||
| 11 | Cross pin | 150L0381 | 1 | ||
| 12 | Set of springs | 150L0455 | 1 | ||
| 13 | Cardan shaft | 63,2 | 150L0323 | ON units | 1 |
| 76,2 | 150L0324 | PB units | 1 | ||
| 14 | Spacer | 5,9 | 150L0444 | 32 cm³ | 1 |
| 12 | 150L0442 | 50 cm³ | 1 | ||
| 18,9 | 150L0447 | 70 cm³ | 1 | ||
| 22,3 | 150L0440 | 80 cm³ | 1 | ||
| 29,1 | 150L0443 | 100 cm³ | 1 | ||
| 15 | O-ring | 60 x 1,5 | 633B0365 | 1 | |
| 16 | Distributor plate | 150L0339 | 1 | ||
| 17 | Gearwheel set 32 cm³ | 11 | 150L4005 | 1 | |
| Gearwheel set 50 cm³ | 17,1 | 150L4003 | 1 | ||
| Gearwheel set 63 cm³ | 21,6 | 150L4002 | 1 | ||
| Gearwheel set 70 cm³ | 24 | 150L4007 | 1 | ||
| Gearwheel set 80 cm³ | 27,4 | 150L4001 | 1 | ||
| Gearwheel set 100 cm³ | 34,2 | 150L4009 | 1 | ||
| 18 | O-ring | 60 x 1,5 | 633B0365 | 2 | |
| 19 | End cover | 150L0392 | 1 | ||
| 20 | O-ring | 10 x 1,5 | 633B1103 | 5 | |
| 22 | Special screw, incl. O-ring | 32,1 | 150L4445 | For OSPM 32 ON | 1 |
| 38,2 | 150L4443 | For OSPM 50 ON | 1 | ||
| 42,7 | 150L4442 | For OSPM 63 ON | 1 | ||
| 44,9 | 150L4435 | For OSPM 70 ON | 1 | ||
| 47,6 | 150L4441 | For OSPM 80 ON | 1 | ||
| 55,3 | 150L4432 | For OSPM 100 ON | 1 | ||
| 23 | Special screw, incl. O-ring | 32,1 | 150L4425 | For OSPM 32 ON / PB | 4/5 |
| 38,2 | 150L4423 | For OSPM 50 ON / PB | 4/5 | ||
| 42,7 | 150L4425 | For OSPM 63 ON / PB | 4/5 | ||
| 44,9 | 150L4425 | For OSPM 70 ON / PB | 4/5 | ||
| 47,6 | 150L4421 | For OSPM 80 ON / PB | 4/5 | ||
| 24 | Name plate | 55,3 | 150L4420 | For OSPM 100 ON / PB | 4/5 |
| 30 | Complete relief valve | 150A6006 | 1 | ||
| 31 | Spring for relief valve | 150L4056 | (excl. spring) | 1 | |
| 45-55 bar | 663X6175 | 1 | |||
| 54-70 bar | 663X6177 | 1 | |||
| 65-85bar | 663X6176 | 1 | |||
| 80-100 bar | 663X6178 | 1 | |||
| Set of seals 150L4054 | |||||
| 1 | Dust seal | 26 x 19 x 4 | 150L0396 | Integrated column | 1 |
| 5 | Shaft seal | 21,9x 17,5 x 3,1 | 150L4011 | 1 | |
| 23,4 x 19 x 3 | 150L4012 | Integrated column | 1 | ||
| 15 | O-ring | 60 x 1,5 | 633B0365 | 1 | |
| 18 | O-ring | 60 x 1,5 | 633B0365 | 2 | |
| 20 | O-ring | 10 x 1,5 | 633B1103 | 5 | |
| 30 | O-ring | 12,4 x 1,78 | 633B11856 | For relief valve adjusting screw | 1 |
| Tightening torque | |||||
| Item | Nm | Ibf·in | |||
| 22 | 30 ± 3 | 265 ± 25 | |||
| 33 | |||||
Tools for OSPM
Tool A: Holding Tool
Description: Tool for holding the OSPM unit during service. Code No.: SJ150L9001-01.
Tool B: Assembly Tool for Shaft Seal ø17.5
Description: Tool for assembling the shaft seal with a 17.5 mm diameter. Code No.: SJ150L4011-01.
Tool C: Assembly Tool for Shaft Seal ø19.2
Description: Tool for assembling the shaft seal with a 19.2 mm diameter. Code No.: SJ150L4012-01.
Tool D: Assembly Tool for Dust Seal Ring
Description: Tool for assembling the dust seal ring. Code No.: SJ150L0396-01.
Tool E: Pliers for Piston in Pressure Relief Valve
Description: Pliers designed for handling the piston within the pressure relief valve. Code No.: SJ150-9000-25.
Tool F: Fork for Fitting Cardan Shaft (OMM)
Description: A fork-shaped tool used for fitting the cardan shaft (OMM). Code No.: SJ151G9000-1.
Tool G: Ordinary Hand Tools
Description: Standard hand tools required for service, including a socket spanner (5/8 in), ratchet spanner (1/2 in), torque wrench (0-70 Nm), Allen keys (5 & 8 mm a/flats), a small screwdriver, and pincers.
Tool H: Lubricants
Description: Vaseline is specified as a lubricant for certain components.
Dismantling the OSPM
The following table outlines the steps and parts involved in dismantling the OSPM unit:
| Item | Part to remove | Action |
|---|---|---|
| Column | If there is a steering column on OSPM, place the unit in the holding tool, on the four locating pins with steering column upwards. Dismantle the steering column. | |
| 30, 31 | Pressure relief valve | If there is a pressure relief valve in OSPM, remove the plastic plug from the adjusting screw and unscrew with the 5 mm a/flats Allen key. Remove the spring and use special pliers-lift the valve cone out of the housing. |
| Lift OSPM clear of the holding tool, turn it so that the output shaft points downwards and place it in the holding tool again. The locating pin in the tool must engage with the OSPM housing. | ||
| 22, 23 | Spec. screws | Remove the screws with a 16 mm a/flats (5/8") spanner. |
| 19 | End cover | Remove end cover sideways. |
| 17, 18 | Gear wheel set | Hold a hand under the gearwheel set to keep the gearwheel from falling out. Remove O-rings. |
| 16 | Distributor plate | Remove distributor plate. |
| 13 | Cardan shaft | Remove cardan shaft. |
| 15 | O-ring | Remove O-ring from housing. |
| 3, 4, 37 | Balls and ball stop | Shake out check valve ball (not in all units), ball stop and emergency steering ball. Use pincers if necessary. |
| 2 | Housing/spool/sleeve | Place the OSPM in the tool again. Lift up steering unit and fixture in one piece and turn it 90° to horizontal. Turn the spool set so that the pin in spool and sleeve is horizontal and push it out. |
| 7 | Bearing | Remove bearing from shaft end. The outer washer may sometimes adhere to the housing. If the washer does not come out with the shaft, it will come out when shaft seal item 5 is being pressed out. |
| 10 | Ring | Remove retaining ring for the neutral position springs. |
| 11 | Cross pin | Press the pin out of the spool set. Carefully press the spool out of the sleeve. |
| 12 | Spring | Press the neutral position springs out of the spool. |
| 1 | Dust seal | Remove the dust seal ring (with a "sharp" screwdriver). |
| 5 | Shaft seal | Remove the shaft seal (with a "sharp" screwdriver if necessary). |
Cleaning, Inspection, Replacement, and Lubrication
- Clean all parts carefully.
- Carefully check all parts and replace imperfect parts, if any.
- Always replace all sealing parts during a repair.
- Before assembly, lubricate all parts with hydraulic oil and grease rubber parts with vaseline.
Assembling the OSPM
The following tables detail the assembly procedures for the OSPM unit:
Assembly Steps
| Item | Part to mount | Action |
|---|---|---|
| 2 | Housing | Place the OSPM housing horizontally in the holding tool, with the hole for the output shaft facing the tool. The locating pin in the tool must engage with the OSPM housing. |
| 5 | Shaft seal | With the assembly tool, the shaft seal must be pressed into the housing. Ensure the small guide piece at the front of the tool remains in the hole for the output shaft when the tool itself is drawn out. Note: Two different tools exist: one for housings for steering column mounting (SJ150L4011-01) and one for housings with integrated steering column (SJ150L4012-01). |
| 2 | Spool/sleeve | Guide spool and sleeve together, turn the spools so that the key slots are opposite each other. |
| 12 | Springs | Insert the curved springs between the flat springs and push them into place. |
| 10 | Spring retaining ring | Center the springs in the spool/sleeve set and guide the ring down over the sleeve. The ring must be able to rotate unimpeded by the springs. |
| 11 | Cross pin | Fit the cross pin in the spool set. |
| 7 | Thrust bearing | Fit the thick race, needle cage, and thin race. Lubricate the output shaft on the inner spool with Molykote PG plastslip 75, on the surface in contact with the shaft seal. |
| 2 | Housing + spool/sleeve | With the housing still horizontal in the holding tool, secure it with one hand. With the other hand, take the assembled spool/sleeve set, ensuring two fingers hold the cross pin (11) in position. Guide the spool set into the housing with the cross pin (11) horizontal. Be careful with the small guide piece from mounting of the shaft seal. With it pressed out by the shaft rotary, with housing and spool set remaining in the tool, lift the whole unit into vertical position. The pin in the spool set must now point towards port P in the housing, either at 6 o'clock or 12 o'clock. |
| 3 | Ball | Place the emergency steering ball in port P. |
| 4 | Ball stop | Place the ball stop in port P. |
| 37 | Ball | Place the check valve ball (if required) in port P. |
| 15 | O-ring | Fit the O-ring in the housing. |
| 16 | Distributor plate | Place the distributor plate on the housing. Turn it so that the holes line up. |
| 13 | Cardan shaft | Fit the cardan shaft into the inner spool and allow it to engage with the pin. If required, use fork SJ 151G9000-1 to retain the cardan shaft. |
| 17 | Gear wheel | When fitting the gearwheel, it must be oriented correctly so that it engages with the cardan shaft. The cross pin (11) in the spool set must line up with the bottom of the teeth in the star. |
| 18 | O-ring | Place the O-rings in the grooves on each side of the gearwheel rim. |
| 17 | Gear ring | Place the gearwheel rim over the distributor plate so that all holes are in line with each other. |
| 14 | Spacer | Place the spacer over the cardan shaft. |
| 19 | End cover | Place the cover so that the hole marked "P" lines up with port P in the housing ("6 o'clock" or "12 o'clock"). |
| 20, 22, 23 | Special screws | Fit screws (with O-rings). Remove the retainer fork. Tighten all five screws (cross pattern) with 30 ± 3 Nm (3 daNm). With open center units, the screw with no oil flow connection must be fitted in port E. If the OSPM must be mounted with a pressure relief valve, lift it out of the tool and place it on the four pins with the axle journals upwards. |
| 30 | Piston | Fit the piston. |
| 31 | Spring | Fit the spring. |
| 30 | Adjustment | Screw in the adjusting screw. |
| Test | Lift OSPM out of the tool and prepare it for testing. The pressure relief valve can be set either on a test panel or in a system with pressure-gauge read-off. Insert plastic plug. | |
| 1 | Dust seal | Guide the dust seal rings down over the shaft end and press into place in the housing with assembly tool SJ 150L0396-01. The dust seal must be fitted after testing so that any leakage from the shaft seal can be detected. |
About Danfoss Power Solutions
Danfoss Power Solutions is a global manufacturer and supplier of high-quality hydraulic and electronic components. They specialize in providing state-of-the-art technology and solutions that excel in harsh operating conditions of the mobile off-highway market. Danfoss helps OEMs worldwide speed up system development, reduce costs, and bring vehicles to market faster, positioning itself as a strong partner in mobile hydraulics.
For further product information, visit powersolutions.danfoss.com.
Danfoss offers expert worldwide support and provides comprehensive global service through an extensive network of Global Service Partners.
Local addresses for Danfoss Power Solutions offices are provided in the original document, including locations in the USA, Germany, Denmark, and China.
Note: Danfoss can accept no responsibility for possible errors in printed material. Danfoss reserves the right to alter its products without notice. All trademarks are the property of their respective companies. Danfoss and the Danfoss logotype are trademarks of Danfoss A/S.
