9U7990 Counter Bore Tool Group for 3176, 3300 and 3400 Series Engines{1201} Caterpillar

Introduction

The 9U7990 Counter Bore Tool Group is used to salvage engine block liner seats which are cracked or damaged. The liner seat is machined out and an insert is installed. The 9U7990 Tool Group contains those items needed for every counterbore operation. Each counterbore operation will also require a cutter plate and a cutter bit. Refer to chart "Cutter Plate, Cutter Bit, and Machining Dimensions for Cylinder Block" for the correct cutter bit, cutter plate, counterbore depth and diameter for each insert. The 9U7988 Riser Plate Group is available for use on 3300 Series Engines eliminating the need to remove adjacent cylinder liners.

9U7990 Counter Bore Tool Group. Consists:

1. 9U7985 Basic Counterbore Tool Group (metal box included but not shown)

4. 9U7986 Base and Micrometer Group (case included but not shown) (part of 9U7985 Basic Counterbore Tool Group)

14. 9U7987 Master Gauge (part of 9U7985 Basic Counterbore Tool Group)

2. 5P7983 Offset Washer (3 required)

3. 0L1328 Bolt, 3/4-16 × 4" (3 required)

5. 5P8248 Washer, 3/4" (3 required)

6. 8T0207 Bolt, M16 × 2 × 100mm (3 required)

7. 5P1656 Tool Remover Hook

8. 5P1630 Drive Adapter

9. 0S1569 Bolt, 5/8-11 × 4" (3 required)

10. 5P8247 Washer, 5/8" (3 required)

11. 1U7575 Allen Wrench, 1/8"

12. 1U7576 Allen Wrench, 5/32"

13. 1U7577 Allen Wrench, 3/16"

15. 9U7984 Depth Set Spacer

Optional Tool

9U7993 Gauge Assembly, Depth (case included but not shown)

Cutter Plate and Cutter Bit (Typical Example)

9U7988 Riser Plate Group (case included but not shown)

The 9U7988 Riser Plate Group is available for use on 3300 Series Engines, eliminating the need to remove adjacent cylinder liners.

Cutter Plate, Cutter Bit, and Machining Dimensions for Cylinder Block

Preparation for Machining

Care and Maintenance of the Hydraulic-Feed Housing

The oil level should always be checked prior to initial use. If a low oil condition exists, tool chatter will occur. The oil level should also be checked periodically to prevent chatter (once a month is sufficient).

Check Oil Level

Lay the feed unit on its side with the oil port 1 in the highest position. Support the feed unit so that it lays in the horizontal position. Remove the oil port plug. The feed unit is full when the oil is filled up into the threads. If the oil level is below the threads, then top off using only 30 weight non-detergent motor oil. Open feed valve and slowly rotate and push the mainshaft of the counterbore tool in and out. Top off the oil level any time the oil level drops below the threads. Continue this procedure until no more bubbles appear and oil level is maintained into the threaded area. Replace oil port plug.

Cutter Plate Inspection

Always inspect the cutter plate for nicks, burrs or excessive wear (it should be smooth) before proceeding. Refer to the chart "Cutter Plate, Cutter Bit, and Machining Dimensions for Cylinder Block" for the correct cutter plate. Inspect and adjust the ball spring plunger screw (brass colored) which provides tension to the cutter bit. To adjust this screw to the proper tension, first install a cutter bit into the cutter slot. Tighten the tension screw completely. Then back the screw 1/4 of a turn. Cutter tension is now properly adjusted.

Verifying the Micrometer Group

9U7986 Base and Micrometer Group (case included but not shown)

NOTE: Check micrometer group prior to setting the cutter. Clean all measuring surfaces before using micrometer, master gauge or cutter. Inspect cutter stop (B) and cutter tip for nicks, if damaged, replace.

1. Install 9U7987 Master Gauge (A) in 9U7986 Micrometer Group with the side marked UP, on top as shown. Hold master gauge firmly against cutter stop (B) and surface (F) when checking master gauge or setting cutter. Turn micrometer thimble until spindle (E) fits snugly against the setting standard. The micrometer should read 5.000".

2. When micrometer adjustment is required, loosen socket head screw (C) and move micrometer slightly away from cutter stop (B). Set micrometer to read 5.000".

3. Slide micrometer to fit snugly against master gauge (A) and securely tighten socket head cap screw (C).

4. Back off micrometer (D) and re-tighten to fit snugly against master gauge (A). Recheck the micrometer which should read 5.000". If it doesn't read 5.000" repeat steps 2 through 4.

Verifying Master Gauge

1. Always check micrometer group first by referring to procedure "Verifying the Micrometer Group."

2. Use a scrap engine block to perform this check.

3. Measure bore in block, add +.040" to measured bore. This will be the test bore dimension.

4. Set cutter to test bore dimension.

5. Bore hole and measure.

6. Compare against set cutter dimension.

Example

If measured bore is 6.291" it is oversize by 001". The master gauge would require .0005" material removal, lap to size by removing material from stem side of master gauge.

If bore measures undersize, example 6.289" then master gauge should be replaced. Order 9U7987 MASTER GAUGE and follow instructions "Machining New Master Gauge to Size."

NOTE: Undersize bore cuts can be caused by damaged master gauge or worn bushings in machine.

Machining New Master Gauge to Size

Use a scrap engine block to perform this test.

1. Measure bore in block, add +.040" to measured bore. This will be the test bore dimension.

2. Set cutter, bore block and measure diameter.

3. Verify cutter still measures original setting of 6.290".

4. If the size of newly cut bore is different than the 6.290" cutter setting with the cutter bit in the micrometer group, then loosen micrometer holding screw and adjust micrometer to read measured bore size of newly cut hole.

5. Tighten micrometer holding screw at this measurement.

6. Place master gauge into micrometer group and turn micrometer thimble down until spindle touches the setting standard.

NOTE: New setting standards are .010" to .020" oversize.

7. Read micrometer.

8. Half the difference between the micrometer reading and 5.000" is the amount to grind or lap off the end of the master gauge to read 5.000" on the micrometer.

Example

New setting master gauge reads 5.010". This is .010" oversize. Grind or lap .005" from the stem side of setting gauge.

9. Carefully grind or lap master gauge. The micrometer should read 5.000". The micrometer and setting standard are now set correctly.

Setting Cutter for Bore Diameter

1. Loosen the set screw in back end of cutter. Push spring loaded adjusting pin into body of cutter all the way. Tighten set screw.

2. After verifying the micrometer group, set micrometer for .040" less than the bore diameter listed in the chart "Machining Dimensions for Cylinder Block."

NOTE: It has been determined through testing, that if two cuts are made to machine for an insert, the bore will be much more accurate and have a higher quality surface finish.

3. Place cutter in micrometer group and hold it firmly against the micrometer spindle (E) and surface (F).

4. Loosen set screw (G) on cutter and allow adjusting pin (H) to push out against the micrometer spindle (E). While holding cutter in place, slowly allow the cutter tip to come in contact with cutter stop (B). Tighten set screw.

5. Back off micrometer thimble and recheck cutter setting. If cutter is not set correctly, repeat steps 3 and 4. Back off micrometer and remove cutter from micrometer group.

Preparing Block for Boring

1. Steam clean block. Remove all top deck dowels.

2. Remove all burrs, rough places and high spots from the top surface of the cylinder block with a large mill cut file. Clean the top surface of the cylinder block to make it free from all foreign material.

3. Use 8T7765 HAND PADS (Scotch Brite) to remove all dents, dirt and burrs from the inside diameters of the counterbore. This area is used by the cutter plate to center the counter bore tool over the bore.

Procedure to Machine Counterbore

Feed Valve Operation

To close feed valve turn valve knob to the right so pointer is horizontal (figure 1). To open feed valve, turn knob to the left so pointer is in vertical position (figure 2).

Helpful Hint

Note the position to the feed valve in each of the following photos.

NOTE: Always remove the spacer plate from the cylinder block, on those engines that have a spacer plate, before doing the counterbore procedure.

NOTE: Prior to placing the boring machine on engine block, make sure that the bottom surface of base plate is clean and burr free, the cutter bit is removed from the cutter plate, and all screws are securely fastened. Cover lower bore in cylinder block to prevent chips from falling onto crankshaft.

1. Refer to the chart "Cutter Plate, Cutter Bit, and Machining Dimensions for Cylinder Block" to select the proper cutter plate and cutter bit. Install cutter plate 1 on the shaft of the counter bore tool and secure with washer 2 and nut 3.

2. Place counter bore tool over bore to be cut. Open feed valve 4 and lower the cutter plate into the bore. Push down firmly on the mainshaft while rotating the cutter plate in the bore to ensure proper alignment.

3. With the cutter plate centered in bore, align baseplate with three cylinder head bolt holes in the block maintaining as much baseplate-to-block contact as possible. Install washers and cap screws through baseplate and into cylinder block. Handle may be swung up for easy access to cap screw.

4. Cross torque head bolts gradually to 50 lb ft (68 N·m). Swing handle 5 down and lock in position. Rotate mainshaft of counterbore tool to ensure straight sided cutter plates are centered in bore. If binding occurs, loosen head bolts and repeat steps 3 and 4. Tapered cutter plates should center by pushing firmly down on mainshaft of the counterbore tool. Tap counterbore tool side to side to center tool and visually inspect for 360 degree contact in the bore.

NOTE: Rotating a tapered cutter plate may wear a groove into the surface of the cutter plate.

5. Retract the cutter plate 1 from the bore and lock it in the full up position by closing the feed valve 4.

6. Refer to "Setting Cutter for Bore Diameter" and set cutter bit.

NOTE: Do not resharpen cutter bit. A resharpened or dull cutter bit loses its center line and will cause the bore to be cut incorrectly.

7. Insert cutter bit 6 all the way into the cutter plate 1 and tighten cutter plate swivel pad set screw. Cutter bit should enter with noticeable drag due to ball spring detent on bottom of cutter plate. The cutter bit must fully contact the main shaft of the boring tool to assure accurate boring.

NOTE: The cutter bit must be inserted into the cutter plate slot with the tip to the lower left side of slot.

NOTE: The cutter bit has a shallow hole which will face downward when the cutter bit is properly inserted into the cutter plate slot.

8. Place a 0.004" inch feeler gauge 7 between the block and the cutter bit 6. Open feed valve and lower cutter plate until the cutter bit rests on the feeler gauge.

9. Tighten swivel pad set screw to secure cutter bit in place.

10. Loosen the set screw on the depth set collar 8 and adjust the set collar up (turn counterclockwise). Attach the depth set spacer 9 to the mainshaft below the depth set collar 8 and resting on the counterbore tool housing.

11. Place the repair insert (A) between the depth set collar 8 and the depth set spacer 9. Lower (turn clockwise) depth set collar down the mainshaft so that it rests squarely on the repair insert and securely tighten the set screw in the depth set collar. Remove the repair insert.

12. Pull mainshaft to the full upright position and lock feed valve 4 in the closed position. Remove feeler gauge.

13. Chuck the 1/2" adapter drive 12 into a 5/8" or 3/4" heavy duty (8 AMP or more) electric drill (300-600 RPM).

14. Install universal drive adapter and drill onto driveshaft of counterbore tool and prepare to bore without stopping until the counterbore tool freewheels.

NOTE: Approximately half way through the cut, the operator should be prepared for the increased load put on the counterbore tool caused by the additional material being cut. A firm grip and a balanced stance are recommended. Operation is complete when counterbore tool freewheels.

15. Remove the electric drill from boring machine. Open feed valve 4 and retract cutter plate 1 to its full up position. Close feed valve 4 to lock cutter plate in the up position.

16. Loosen swivel pad set screw and insert tool removal hook 13 into shallow hole in bottom of cutter bit 6 and pull to remove cutter bit 6 from cutter plate 1.

17. Measure the actual depth of cut with 9U7993 Depth Gauge Assembly and determine the difference between the actual bore depth and the bore depth in the chart "Cutter Plate, Cutter Bit, and Machining Dimensions for Cylinder Block."

18. Loosen set screw of depth collar 8 and loosen depth collar 8 clockwise 1 mark for each .001" of difference between the measured bore depth and the desired bore depth.

19. Reset cutter bit to bore diameter in the chart "Cutter Plate, Cutter Bit, and Machining Dimensions for Cylinder Block."

20. Remove all chips and foreign material from the cutter recess and the access areas where the cutter contacts the mainshaft. It is very simple to clean these areas with a cotton swab. Foreign material in these areas could cause the next bore to be cut oversize.

21. Repeat steps 13 through 16.

22. Remove the counterbore tool.

23. Clean away all shavings and deburr bore with 8T7765 Hand Pad (Scotch Brite).

24. Refer to instructions "Cylinder Liner Projection" (for the appropriate engine) and measure the cylinder liner projection.

Cylinder Liner Projection (3176)

Tools Needed

Check cylinder liner projection above top of spacer block as follows:

1. Make certain the cylinder liner flange and cylinder block are clean. Do not install liner seals when this check is made.

Checking Cylinder Liner Projection

1. 2S5658 Washer

2. 7X2558 Bolt

3. 8F1484 Washer

4. 7K1977 Washer

5. Spacer block

6. Cylinder liner

7. Cylinder block

2. Install washers and bolts as shown around the cylinder liner. Tighten all bolts finger tight.

3. Tighten the bolts evenly, in five steps; 14 N·m (10 lb ft), 25 N·m (20 lb ft), 40 N·m (30 lb ft), 55 N·m (40 lb ft) and then to 70 N·m (50 lb ft).

4. Tighten the bolts again to 70 N·m (50 lb ft).

5. Use a 8T0455 Liner Projection Tool Group to measure liner projection. Special Instruction Form No. SMHS7727 gives more information for the measurement procedures.

6. To zero the dial indicator, use the back of the 1P5507 Gauge with the dial indicator mounted in the 1P2402 Gauge Body.

7. Liner projection must be 0.040 to 0.200 mm (.0016 to .0079 in). (Make the measurement to the top of the liner flange, not the inner ring). The maximum differential between high and low measurements made at four places around each liner is 0.05 mm (.002 in). The average projection of liners next to each other must not be more than 0.05 mm (.002 in). The maximum difference in the average projection of the cylinder liners under one cylinder head must not be more than 0.10 mm (.004 in).

NOTE: If liner projection changes from point to point around the liner, turn the liner to a new position within the bore. If still not within specifications move liner to a different bore.

NOTE: When liner projection is correct, put a temporary mark on the liner and spacer block so when the seal is installed, the liner can be installed in the correct position.

Cylinder Liner Projection (3300)

Tools Needed

The correct cylinder liner projection is important to prevent a leak between the liner, cylinder head, and block. Check cylinder liner projection above the spacer plate as follows:

1. Be sure that the surfaces of the cylinder block, cylinder liner, and the spacer plate are clean.

2. Install the spacer plate gasket and spacer plate (4) on the cylinder block. Use 0S1589 Bolts (1) with two 1S0379 Washers on each bolt to hold the spacer plate to the cylinder block. Put two bolts with washers on each side of the opening for the cylinder liner. Tighten the bolts evenly, in four steps; 14 N·m (10 lb ft), 35 N·m (25 lb ft), 70 N·m (50 lb ft), and 95 N·m (70 lb ft).

NOTE: To keep from moving bolts and washers as each liner is checked install two bolts with washers on each side of each cylinder liner, along the complete length of the spacer plate.

3. Install the cylinder liner without seals in the cylinder block. Put adapter plate (7) on the cylinder liner as shown. Install crossbar (2) with 1D4595 Bolts (3), 2S0736 Washers and 3H0465 Plates (5) as shown. Tighten the bolts evenly, in four steps; 7 N·m (5 lb ft), 20 N·m (15 lb ft), 35 N·m (25 lb ft) and 70 N·m (50 lb ft). The measurement from the bottom of crossbar (2) to the spacer plate, must be the same on both sides of the cylinder liner.

4. Install the 1P5512 Contact Point on dial indicator (6). Put the dial indicator in the 1P2402 Gauge Body. To adjust the dial indicator to zero, put dial indicator and gauge body on the 1P5507 Gauge. Move the dial indicator until the hand moves 1/4 turn. Tighten bolt on body to hold the dial indicator in this position. Turn the dial face until the zero is in alignment with the hand.

Measuring Cylinder Liner Projection

1. 0S1589 Bolt with two 1S0379 Washers

2. Crossbar

3. 1D4595 Bolt

4. Spacer plate

5. 3H0465 Plates

6. 1P2403 Dial Indicator

7. 1P2394 Adapter Plate

5. Measure the cylinder liner projection as close as possible to the four corners of the adapter plate on the liner. The liner projection must be 0.033 to 0.175 mm (.0012 to .0069 in.). The difference between the four measurements must not be more than 0.05 mm (.002 in.). The difference in the average cylinder liner projection of liners next to each other must not be more than 0.05 mm (.002 in.). The maximum difference in the average projection for all cylinder liners must not be more than 0.10 mm (.004 in.) for the 3306B Engine and 0.08 mm (.003 in.) for the 3304B Engine.

NOTE: If the liner projection changes from point to point around the liner, turn the liner to a new position in the bore. If the liner projection is still not to specifications, move the liner to a different bore.

6. When the cylinder liner projection is correct, put a temporary mark on the liner and the spacer plate so at final installation the liner can be installed in the correct position.

Cylinder liner projection can be adjusted by the removal of material from (machining) the contact face of the cylinder block with the use of 9U7990 Counter Bore Tool Group.

Projection of Cylinder Liner (3400)

Tools Needed

Check liner projection above top plate as follows:

1. Make certain that top plate (4) and the cylinder liner flange are clean. Install a new top plate gasket, but do not install liner seals when this check is made.

Holding Top Plate to Cylinder Block (Typical Example)

1. 3H0465 Plate

2. 1P2396 Puller Plate

3. 2F0126 Seals (copper washers)

4. Top plate

Rework old spacer plate to fabricate "figure 8" sections.

NOTE: On engines with aluminum spacer plates, use care in obtaining liner projection measurements to prevent marring the surface. To prevent damage to the spacer plate, use copper washers instead of hardened steel washers with the spacer plate bolts. Do not excessively tighten the spacer plate bolts.

In addition, to increase the accuracy of liner projection measurements and also prevent damage, cut "figure 8" sections from an old spacer plate and install them under the spacer plate bolts. These are the center ribs between the cylinder holes from a scrapped 2W8601 Spacer Plate as shown in the illustration. The top and bottom radii of the "figure 8" section should coincide with the radii of the washers.

2. Use 3/4 - 16 NF bolts, 76.2 mm (3.00 in) long, with two 2F0126 Seals (3) on each bolt to hold the top plate (4) to the cylinder block. Install two bolts with seals (3) on each side of the cylinder liner. Tighten the bolts evenly, in four steps; 14 N·m (10 lb ft), 35 N·m (25 lb ft), 70 N·m (50 lb ft) and then to 95 N·m (70 lb ft).

NOTE: To keep installation and removal of bolts and washers to a minimum as each liner is checked, install two bolts with washers on each side of each cylinder liner along the complete length of the top plate.

3. Use a 1P2396 Puller Plate (2), three 3H0465 Plates (1), 8B7548 Push-Puller (6), and two 3/4 - 16 NF bolts, 177.8 mm (7.00 in) long to hold the liner down.

4. Tighten the bolts evenly in four steps; 7 N·m (5 lb ft), 20 N·m (15 lb ft), 35 N·m (25 lb ft) and then to 70 N·m (50 lb ft). Distance from bottom edge of 8B7548 Push-Puller (6) to top plate must be the same on both sides of cylinder liner.

5. Use a 8T0455 Liner Projection Tool Group to measure liner projection. Special Instruction, Form No. SMHS7727 gives more information for the measurement procedures.

6. To zero dial indicator (5), use the back of 1P5507 Gauge with dial indicator (5) mounted in 1P2402 Gauge Body (7).

7. Liner projection must be 0.03 to 0.15 mm (.001 to .006 in). (Make the measurement to the top of the liner flange, not the inner ring). The maximum differential between high and low measurements made at four places around each liner is 0.05 mm (.002 in). The average projection of liners next to each other must not be more than 0.05 mm (.002 in). The maximum difference in the average projection of the cylinder liners under one cylinder head must not be more than 0.10 mm (.004 in).

Measuring Liner Height Projection (Typical Example)

5. Dial indicator

6. 8B7548 Push-Puller

7. 1P2402 Gauge Body

NOTE: If liner projection changes from point to point to point around the liner, turn the liner to a new position within the bore. If still not within specifications more liner to a different bore.

NOTE: When liner projection is correct, put a temporary mark on the liner and top plate so when seals and band are installed, the liner can be installed in the correct position.

The contact face of the cylinder block can be machined with use of the 9U7990 Counter Bore Tool Group to adjust liner projection.

Repair Service

For repair of counterbore tool contact: