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TECH TALK  - Page 5

Page 1 - Transistorization of SU Fuel Pump

Page 3 - Australian MG Register

Page 5 - Lucas Info - Starter motors, Polarisation of Dynamos, MGB Circlip

Page 7 - Starter fitted to BMC MK II

Page 9 - How to Develop the MGC for Everyday Use

Page 2 - One Grease Nipple  - Two Destinations 

Page 4 - Lucas Info - Wiring, MGA Wiper Motors, Wear in Lucas Eclipse Drives MGB MK II

Page 6 - Lucas Info - Bearing Replacement, Alternator models for MG's,

Page 8 - Fitting Mazda seats to a Mark II MGB Roadster

Page 10 - LUCAS Distributors, Why they need to be remapped.

Page 11 - Air Conditioning your B-GT, C-GT, or B- GTV8

Page 13 - Polaris HUD Display Speedometer

Page 12 - Electric Power Steering for MGA, MGB & MGC

Page 14 - Know Your Tyres

Page 15 - Replacing a 12 volt battery with the latest technology Century Battery.

Starters for 1950-60 CARS – MG TD, MG TF,  ZA and ZB
Modified SB drive as fitted to M-35G/1 Starters  (dated 3 September, 1958)

The latest M-35G/1 Starters are now being fitted with modified Lucas SB drive components.

The solid splined space washer 250987 formerly fitter between the screwed sleeve and the spring has now been superseded by a hardened dished spline washer. This change necessitates an alteration in the length of machined portion of the armature on which the pinion slides also, the length of the splined portion.

The former armature Part No 250851 is now superseded by armature 54250096 and each armature will include the pressed steel spline washer 291971 and fitting instructions.


The starting motors affected are as follows:

Starting Motors                  New armature and splined

Service No                  Old armature                washer
25062                                                    250851                  54250096 armature;291971 washer

The Australian made M-35G/1 Starter 67201A is however, fitted with an armature marked 251991 and dished splined washer 291971. For servicing the Cheltenham produced starter 67201 use standard replacement armature 54250096.

Care should be taken not to confuse the above with armature 250702 which will continue to be supplied together with distance washer 291971 so that it can be used with a modified drive.


When fitting a new service replacement or repaired dynamo it must be polarized to suit the vehicle’s electrical system and therefore the following procedure must be adopted.

To polarize – fir the dynamo to the vehicle but do not at this stage connect cables to the ‘D’ and ‘F’ terminals. Determine which battery terminal is earthed on the vehicle and then temporarily connect a length of wire to the positive terminal (for negative earthed vehicles) or negative terminal (for positive earthed vehicles). Hold the other end of the wire against ‘F’ terminal of the dynamo for 3 – 5 seconds, after which time the dynamo is then correctly polarized. Remove the temporary connection and then restore the original cables to the ‘D’ and ‘F’ terminals of the dynamo.

Below is a diagrammatic explanation of how to polarize the dynamo for the putpose of explaining the procedure

1. Fit dynamo to vehicle
2. Connect jumper lead from battery insulated terminal as shown in the diagram.

MGB   X418G Starter Part No25555  - Replacement Circlip (dated Apr 1966)

Following investigation into reports or noisy starter drives on MGB sports cars, a revised circlip has been designed to held the barrel locking nut into the pinion and barrel assembly.

The new circlip Pt No 5424-551 has a single wave form and should be used as a replacement whenever complaints of noisy starters are received.

Starters will shortly be manufactured with this circlip incorporated and these can be recognized by a suffix advanced to ‘F’ after the starter part number.

The circlip must be assembled with the wave and two ends pointing towards the barrel (see illustration).

Note: The ends of the circlip must not be visible in the slips of on the barrel when it is assembled.

For Sale now in Classifieds

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