590A

ElectricalComponents SERVICE BULLETIN NO. 590ADivision Engineering AspectsSidney, New York 13838 are FAA Approved

Printed May 1978Page 1 of 3 Pages

Bendix

AIRCRAFTSUBJECT: Rotating magnet to housing clearance, D-2000/D2200 series

magnetos.

REASON FOR BULLETIN: Part 1: To alert users of D-2000/D2200 magnetos of a possibleproblem and to provide a procedure for detection.Part 2: To provide instructions for return of magnetos when factoryrepair is required.

NOTE

This Service Bulletin supersedes S.B. 590 dated May,1977 and changes are indicated by black margin lines.The major change is in the magneto serial number rangeand all serial numbers specified under EQUIPMENTAFFECTED are involved, regardless of accumulated "inservice" time, unless they have previous compliance to S.B. 590.

EQUIPMENT AFFECTED: Part 1: D-2000/D2200 Series Magnetos with red name plates, havingserial numbers of 5145 through serial number 11744 and X-2484 through X-2562 with 4 hex head cap screws asindicated in figure 1, without the letter A or R preceding theserial number.

Part 2: D-2000/D2200 Series Magnetos with blue nameplates havingserial numbers below 701001, with 4 hex head cap screws asindicated in figure 1 without the letter A or R preceding theserial number.

Figure 1. Position of 4 Hex Socket Head Cap Screws

Note

The A serial number prefix indicates that the aspects of thisbulletin have been accomplished by Bendix. The R prefixindicates that aspects of this bulletin have been previouslyaccomplished in the field.



Bendix

Maintenance (Spare) Parts Affected:Same as information in Equipment Affected section.

Compliance:1. All subject magnetos covered by "Equipment Affected" nolater than 10 hours in service after receipt of this ServiceBulletin.

2. All subject spare magnetos covered by "EquipmentAffected" upon receipt of this Service Bulletin.

General Information:Part 1.

Investigation has revealed the possibility that a smallpercentage of D-2000 & D-2200 Series magnetos usinga "wedge" coil retention device may have insufficientclearance between the magneto rotor and the housingpole shoes. If interference should occur between theseparts, complete loss of ignition can result. To guardagainst such failure, compliance with the instructions inthis bulletin, should be followed.

Part 2.When it is found that a magneto does not haveadequate rotor-to-housing pole shoe clearance, returnthe complete magneto along with the two capacitorsfrom the magneto cover, directly to the factory for nocharge warranty repair. Shipment should be by fastestsurface transportation and the parcel clearly addressedand identified as follows to assure rapid handling whenreceived. Do not return the Ignition Harness.

SHIP TO: The Bendix CorporationElectrical Components DivisionSidney, New York 13838Attention: Product Support Manager

D-2000 Warranty, Service Bulletin No. 590A

Detailed Instructions:

1. Remove cover from magneto and magneto from engine.

2. Remove magneto breaker cam or cams using offsetscrewdriver to release main cam from shaft.

3. Remove distributor block hold down screws andassociated parts.

4. Lift off distributor block together with the breakerassemblies.

5. Inspect the rotating magnet for presence of score marksaround its diameter. If score marks are seen, the rotorhas been rubbing and the magneto must be removedfrom service and the complete magneto returned to themanufacturer for repair.

6. If no score marks are seen, place the rotating magnet inany one of its neutral positions.

7. Check rotor-to-housing pole shoe clearance byattempting to insert at the same time four pieces of.007" shim stock* between the rotor outside diameterand the housing pole shoes. One piece should be ateach of the 4 locations shown in figure 2.

Figure 2. Positions for Inserted Pieces of .007 Shim Stock

The shim stock should be wide enough to span the width ofeach housing pole shoe and insertion should be able to beaccomplished at all positions for the full depth of the rotor.

When all 4 pieces of shim stock are in position, it indicatesthat the rotor-to-housing pole shoe clearance is at least .007"all around.8. If step 7 can be accomplished, assemble the distributor

block to the housing, install the cam or cams and timethe magneto following instructions in the D-2000 & D-2200 Series Magneto Ignition Systems Overhaulmanual, Bendix Form L-945.

*Non-magnetic shim stock is recommended. (Experiencehas shown that IBM punch card stock is normally .007" thickand can be used for this operation. Check card thicknesswith micrometer before use.)



Bendix

9. If step 7 cannot be accomplished, the rotor-to-housingpole shoe clearance is insufficient and the entiremagneto with the two capacitors from the magnetocover must be returned directly to the factory as detailedby General Information part 2.

CAUTION

Under no circumstances should a magnetohaving less than .007" clearance all around,be returned to service.

10. After satisfactory completion of steps 7 and 8, identifycompliance with the Service Bulletin by stamping theletter R ahead of the serial number on the magneto dataplate and make appropriate engine log book entry.

11. Compensation for the work involved in complying withthe provisions of Service Bulletin No. 590A will be

made upon submission of a warranty claim. The claimmust be submitted through a currently authorizedBendix distributor or Bendix service station.Reimbursement for expenses incurred in accomplishingcompliance with Service Bulletin No. 590A will be madein accordance with established Bendix Warrantyprocedures.

Parts Required:As determined by inspection.

Special Tools Required:Timing light, Bendix 11-9110-1 or equivalent..007" shim stock.

Man Hours Required:2 1/2 hours maximum.

Weight Change:None.

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590A