Char-Lynn® Series 10 Steering Control Unit - Wide Angle

Introduction

This manual provides service information for Eaton's Char-Lynn® Series 10 Steering Control Units with wide angle feature. Step-by-step instructions for complete disassembly, inspection, and reassembly of the control unit are given.

The following recommendations should be followed to ensure successful repairs:

• Most repairs require the removal of the control unit from the vehicle.
• Cleanliness is extremely important.
• Clean the port areas thoroughly before disconnecting the hydraulic lines.
• Plug the control unit ports and cover open hydraulic lines immediately after they have been disconnected.
• Drain the oil and clean the exterior of the control unit before making repairs.
• Wash all metal parts in clean solvent.
• Use filtered, moisture-free compressed air to dry the parts. Do not wipe them dry with paper towels or cloth – lint in a hydraulic system will cause damage.
• Always use new seals when reassembling hydraulic control units.
• Lubricate new rubber seals with petroleum jelly before installation.
• Torque all bolts over gasketed joints, then repeat the torquing sequence to make up for gasket compression. After all repairs are complete, it is essential to verify the accuracy of control unit repairs on an authorized test stand.

Ordering Parts

How to Order Replacement Parts

Each order must include the following:

1. Product Number
2. Date Code
3. Part Name
4. Part Number
5. Quantity of Parts

Refer to specific part listings for your Char-Lynn® Steering Control Unit when ordering replacement parts. Listings are available from Eaton. A sample tag shows identification.

For additional literature, contact:

Eaton Hydraulics
14615 Lone Oak Road,
Eden Prairie, MN 55344
USA
www.eaton.com/hydraulics

Tools Required For Disassembly and Assembly

• Screwdriver (102-152 mm [4 in. - 6 in.] long, x 3 mm [1/8 in.] wide flat blade).
• 1/2 inch socket for current hex head cap screws.
• Breaker bar wrench.
• Torque wrench (30 Nm [300 lb-in] capacity).
• T-Handle No. 600604*
• Retaining ring pliers - Eaton PN 600610*

Special Tools:

• Plunger and Sleeve Tool No. 600792-001*

* Tools available by special order through our service department.

Parts Assembly Drawing

An exploded view of the Char-Lynn® Series 10 Steering Control Unit components is provided, illustrating the arrangement of various parts.

Parts List

Series 10 Steering Control Unit

Gerotor Specifications

Disassembly

Cleanliness is extremely important when repairing a steering control unit. Work in a clean area. Before disconnecting lines, clean port area of unit thoroughly. Use a wire brush to remove foreign material and debris from around exterior joints of the unit.

It is recommended to keep the unit in a vise during disassembly. Follow the clamping procedures explained throughout the manual.

1. Clamp unit in vise, meter end up. Clamp lightly on edges of port face sides. Use protective material on vise jaws. Housing distortion could result if jaws are overtightened. (See Figure 1 for clamping orientation).
2. Remove the 5/16 inch cap screws. (Illustrated in Figure 2).
3. Remove the end cap. (Illustrated in Figure 2).
4. Remove the seal from the gerotor (meter). (Illustrated in Figure 2).
5. Remove the gerotor (meter). Be careful not to drop the star component. (Illustrated in Figure 2).
6. Remove the seal from the spacer plate. (Illustrated in Figure 3).
7. Remove the spacer plate. (Illustrated in Figure 3).
8. Remove the seal from the housing. (Illustrated in Figure 3).
9. Engage a tool with the splined end of the spool.
10. Protect the gerotor star and hand with a shop towel; hold the gerotor star and splined drive from turning.
11. Twist the tool to compress the centering spring radially (clockwise or counter-clockwise), decreasing the coil diameter of the centering spring. This allows it to be removed along with the spool, sleeve, drive, pin, bearing race (item 2), retaining ring, and needle thrust bearing. (Note: Bearing races, retaining ring, and needle thrust bearing are not shown on the drawing in step 11's illustration. The centering spring is shown compressed.)
12. With the drive held stationary and the centering spring compressed, carefully push these assembled parts out of the housing. (Illustrated in Figures 3 and 4, showing various components like spool, sleeve, drive, pin, bearing race, retaining ring, and needle thrust bearing).
13. Remove the housing from the vise.
14. Carefully remove the bearing and race, anti-cavitation valves, and manual steering check valve (roll pin and ball) from the bolt holes by tipping the housing Gerotor side down. (See Figure 3 for orientation).
15. Do not remove any valves other than the manual steering check valve assembly and anti-cavitation valve assembly. All other valves are factory preset and are non-serviceable.
16. Carefully remove the seal with a thin-blade screwdriver. Do not scratch the seal groove with the screwdriver.
17. Use a thin-bladed screwdriver to pry the dust seal from the housing. Do not damage the housing.
18. Push the pin from the spool and sleeve assembly.
19. Remove the drive
20. Push the spool partially from the control end of the sleeve, then carefully remove the centering springs and retaining ring from the spool by hand. (Illustrated in Figures 8, 9, 10, 11, 12, 13, 14, showing detailed steps for seal installation and component removal).
21. Remove the thrust bearing race and needle thrust bearing.
22. Remove the retaining ring (use retaining ring pliers, Eaton part no. 600610), bearing race, centering spring, pin, drive, spool, and sleeve. (Illustrated in Figures 15 and 21, showing the sequence of component removal).

Assembly

Cleanliness Recommendations

Check all mating surfaces. Replace any parts that have scratches or burrs that could cause leakage. Clean all metal parts in clean solvent. Blow dry with air. Do not wipe dry with cloth or paper towel because lint or other matter can get into the hydraulic system and cause damage. Do not use grit paper or file or grind these parts.

Note: Lubricate all seals with clean petroleum jelly. A good service policy is to replace all old seals with new seals. Do not use excessive lubricant on seals for the meter section. Refer to parts lists covering your steering control unit when ordering replacement parts.

Place housing on a flat work area on a clean lint-free cloth. Install press-fit 24,9 mm [.98 in.] ID seal in housing with the metal surface of the seal facing toward the housing (Figure 6).

2-Piece Shaft Seal Installation

For installation of o-ring: 4999651-001 and Seal 9332-000:

1. Place housing on a flat work area as shown in Figure 7.
2. Lubricate the seal and o-ring with hydraulic oil before installation.
3. Align the sleeve with the housing bore (Figure 7).
4. Insert the sleeve into the housing bore (Figure 8).
5. Place the o-ring on the plunger (Figure 9).
6. Align the seal with the plunger. The cross-section "L" shape of the seal should be upside down (Figure 10).
7. Push the seal onto the plunger. The lip of the seal should be between the o-ring and the plunger. No gap should exist between the o-ring and the seal (Figure 11).
8. Align the plunger with the sleeve (Figure 12).
9. Push the plunger into the sleeve until it bottoms out, rotate 1/4 turn (Figure 13). While holding the sleeve in the housing, withdraw the plunger. Withdraw the sleeve.
10. Inspect seal installation. The seal and o-ring must both be within the shaft seal counterbore of the housing (Figure 14).
11. Clamp the housing in a vise (Figure 15).
12. Assemble the spool and sleeve carefully so that the spring slots line up at the same end. Rotate the spool while sliding the parts together. Test for free rotation. The spool should rotate smoothly in the sleeve with fingertip force applied at the splined end.
13. Apply a light coating of clean hydraulic fluid to the spool and slide it into the sleeve along with the ball checks, if applicable.
14. Install the drive and pin.
15. Install the centering spring. Position one end of the spring in the slotted end of the spool and sleeve, and compress the spring radially (CCW) to engage the free end of the spring.
16. Install the bearing race and retaining ring (use retaining ring pliers, Eaton part no. 600610) onto the spool.
17. Apply a light coating of petroleum jelly to the inside diameter of the previously mounted dust seal in the housing.
18. Apply a light coating of petroleum jelly to the needle thrust bearing and the second bearing race. Position each part onto the spool as shown in the enlarged section drawing. The needle thrust bearing goes between the two bearing races and must be centered around the retaining ring.
19. Apply a light coating of clean hydraulic fluid to the spool and sleeve assembly and slide it into the housing (see steps 20-25). Important: Do not damage the dust or shaft seals.
20. Protect the gerotor star and hand with a shop towel; hold the gerotor star and splined end of the drive to keep it from turning.
21. Insert the tool through the housing; engage with the splined end of the spool assembled inside the sleeve, centering spring, drive, pin, bearing race, retaining ring, needle thrust bearing, second bearing race, shaft seals, and backup washer. Twist the tool to compress the spring coils radially (CW or CCW).
22. Keep the centering spring compressed, and carefully insert these assembled parts into the housing. DO NOT FORCE. (Bearing races, retaining ring, needle thrust bearing are not shown on the drawing at left. Centering spring is shown compressed.)
23. Release the centering spring tension.
24. Remove the gerotor star.
25. Remove the tool.
26. Install the 72,6 mm [2.86 in.] ID O-ring in the housing (Figure 20).
27. Install the anti-cavitation valves and manual steering check valve (if used) in the holes, as shown in Figure 20. After installing the balls, inspect the holes to make sure they are properly seated.

Timing Reference Data

Align star valleys (reference A) with marked drive 1 and drive 2 (reference B). Valleys must align with the pin. Note the parallel relationship of reference lines A, B, C, and D in Figure 21. Align bolt holes without disengaging the gerotor (meter) from the drive.

1. Install the spacer plate. Align bolt holes in the spacer plate with the tapped holes in the housing.
2. Lubricate and install the 72,6 mm [2.86 in.] ID seal in the spacer plate.
3. Install the gerotor (meter) with the seal groove up, noting the position of the star valleys in relation to the marked drive.
4. Lubricate and install the 72,6 mm [2.86 in.] ID seal in the gerotor ring.
5. Lubricate and install the 72,6 mm [2.86 in.] ID seal in the gerotor (meter).
6. Install the end cap on the gerotor, aligning holes.

Note: Check to ensure that the spool and sleeve are flush or slightly below the 14-hole surface of the housing.

Attention: Clean the upper surface of the housing by wiping with the palm of a clean hand. Clean each of the flat surfaces of the meter section parts in a similar way just before reassembly. Do not use cloth or paper to clean surfaces.

36. Install 7 dry cap screws in the end cap. Pretighten cap screws to 17 Nm [150 lb-in], then torque screws to 28-34 Nm [250-300 lb-in] in the sequence shown in Figure 23.

Contact Information

Eaton Hydraulics Business USA
14615 Lone Oak Road
Eden Prairie, MN 55344
USA
Tel: 952-937-9800
Fax: 952-294-7722
www.eaton.com/hydraulics

Eaton Hydraulics Business Europe
Route de la Longeraie 7
1110 Morges
Switzerland
Tel: +41 (0) 21 811 4600
Fax: +41 (0) 21 811 4601

Eaton Hydraulic Business Asia Pacific
11th Floor Hong Kong New World Tower
300 Huaihai Zhong Road
Shanghai 200021
China
Tel: 86-21-6387-9988
Fax: 86-21-6335-3912

© 2009 Eaton Corporation. All Rights Reserved. Printed in USA. Document No. C-STCU-TS008-E. February 2009.