Flywheel Chamfering Procedure
A flywheel is a precision machined part. It must be properly machined to provide effective performance. The flywheel may be taken to a machine shop for machining, or may be machined at a Saturn retail facility using an adapter set on a brake lathe.^ If your Saturn retail facility is equipped with an Accu-turn (TM) Brake Lathe, it is necessary to order an Accu-turn (TM) Flywheel Adapter Set. Call Dealer Equipment at (800) GM-TOOLS (800 468-6657) to order an Accu-turn TM Flywheel Adapter Set (P/N 54-436057).
^ If your Saturn retail facility is equipped with an Ammco(R) Brake Lathe, the accessories needed for creating a chamfer on the flywheel should be included. The Ammco(R) Brake Lathe offers no provision for measuring depth of cut. The depth of cut can be measured using a dial indicator.
^ If your Saturn retail facility is equipped with a brake lathe other than the two manufacturers mentioned above, contact that in an manufacturer's's representative for the necessary flywheel machining accessories.
1. Remove clutch cover, clutch disc, and flywheel according to procedures in the appropriate year Manual Transaxle Service Manual.
2. Measure and mark the flywheel in the area to be machined. Measure 60 mm-64 mm (2.4-2.5 in.) starting from the outside edge of the flat portion of the flywheel moving towards the inside edge of the flywheel. The material to be removed is from the inside edge of the flywheel to the measured mark.
3. For Ammco(R) lathes: Rotate the lathe spindle hand wheel clockwise (right) to the end of its travel. Then rotate the spindle hand wheel counter clockwise (left) approximately 2-1/2 turns. Mount the flywheel onto the arbor with the clutch side towards the lathe. Slide the centering cone (# 3903) with the taper towards the flywheel onto the arbor. Next, slide the centering cone spring (# 3110) and hub-less adapter (# 9489) onto the arbor. Use double taper adapters (# 9193 and # 9194), as well as the self-aligning spacer (# 9492) to space out the arbor.
IMPORTANT:
The flywheel is centered on the alignment cone chamfer.
IMPORTANT:
Both surfaces of the inside bell clamp must be parallel or the flywheel will not turn on a parallel plane with the cutting tip. Even the smallest nick, scratch, or loose chip on the mating surfaces can cause incorrect flywheel mounting alignment. This will cause inaccurate machining. Always inspect the surface of each bell clamp. Wipe each part clean before and after using it. If a bell clamp is dropped or damaged, contact dealer equipment or the manufacturer to obtain a new bell clamp.
For Accu-turn TM lathes:
Using contents found in the flywheel adapter set, mount the first bell clamp, alignment spring, washer, alignment cone, flywheel and second bell clamp onto the lathe arbor.
4. Use the largest possible "spacers" to fill out the arbor and allow the arbor clamp nut to mount.
5. Wrench tighten the arbor clamp nut* counterclockwise until the flywheel and adapters begin to turn on the arbor. Then continue to advance the wrench 1/6 of a turn.
IMPORTANT:
Do not overtighten the arbor clamp nut.
*Use deep side of nut on Ammco(R) lathes manufactured after November, 1996. (Arbor is 1 inch longer)
6. For Ammco(R) lathes: rotate the lathe cross feed hand wheel inward (clockwise/right) to its end of travel. Then rotate the cross feed hand wheel approximately 8 turns out (counter-clockwise/left). Lock knob at bottom of guide bar.
7. Position the tool bit holder onto the boring bar. Make sure the tool bit holder is flush in boring bar slot. The slot must be clean to ensure correct slot angle. Tighten the square head screw(s).
IMPORTANT: For Accu-turn (TM) lathes:
replace the short right hand tool holder in the boring bar with the left hand tool holder from the twin cutter.
8. Position the boring bar by loosening the boring bar clamp nut and sliding the boring bar inward toward the flywheel until the cutting tip is close to the measured mark.
9. Cheek the boring bar cutting tip for excessive wear or damage and replace if necessary. Always use a cutting tip recommended by the lathe's manufacturer.
10. Angle the cutting tip so that it is approximately 30 degrees to the flywheel. To aid in this procedure, use a protractor to cut out a template similar to the one shown and align it to the carbide tool bit.
a. Adjust the arbor and boring bar so that the carbide bit contacts the inside edge of the flywheel.
b. Position the carbide bit over the inside edge of the flywheel so that the edge will contact the bit in the middle of its leading side.
c. Adjust the bit so that it is positioned 30 degrees to the flywheel.
11. To achieve the best cutting position, the entire boring bar clamp may be swiveled. To optimize lathe performance, minimize the boring bar length while still being able to reach the flywheel.
12. Tighten the stud nut.
Torque: 34 Nm (25 ft-lbs)
13. Start the lathe.
IMPORTANT:
Auto feed functions must not be used for this procedure.
14. Remove necessary metal from flywheel:
^ Total depth of cut should be 3-4 mm (0.12-0.16 in.).
For Ammco(R) lathes:
^ Turning the spindle handwheel to the right increases depth of cut.
^ Turning the cross feed handwheel outward moves the tooling across the flywheel.
For Accu-turn lathes:
^ Turning the drum feed handwheel clockwise increases depth of cut.
^ Turning the rotor feed handwheel counter-clockwise moves the tooling across the flywheel.