M45G Starter Rebuild

[Mike’S-a-loon]

Hi everyone,

Has anyone rebuilt their starter motor recently? I have been trying to source a kit, but can't locate one. 

I can find brushes, springs, brush holder etc as separate items, from different sources, but to be honest I suspect brushes is all that's required, though I haven't pulled the starter off the car yet.

Am I right in assuming the brush holder and springs are most likely ok?

[enigmas]

Hi Mike don't bother rebuilding the OEM starter motor on your P5B unless you need it to be totally original. Why not fit a brand new reduction starter motor from a Range/Land Rover. They're incredibly inexpensive, a direct fit amd will spin your 3.5 P5B engine over like it was a little 4 banger. This is what I use on the 11:1 compression ratio 4.4 P76 V8 in my Coupe. There's absolutely no comparison with regard to cranking speed...Winter, Summer, hot or cold. As a plus the reduction starter motor is tiny in comparison and easy to fit.

Click on the link below...and look down the page as well.

Range/LandRover Reduction Starter Motor

[Mike’S-a-loon]

Good advice, Vince. Done! A bit more expensive than the one you posted, but a local supplier and next day delivery!

[enigmas]

Hi Mike,
Could you provide some feedback with your experience of the reduction starter motor once fitted? 😎

[Mike’S-a-loon]

So, job done.

Fortunately, the starter gave up the ghost at home, in the carport. This could have been better (in the garage), but definitely could have been infinitely worse...

It is winter here in Oregon. Happily, a relatively mild one, but still miserable enough that I fought myself over beginning the process. Strangely, condensation was settling all over the car overnight, to the point that the concrete underneath was soaking wet, mixing with the fall leaves and dripped oil into a lovely slurry of miserableness.

To be honest, in the 30 years I have owned Winston, I am not sure if I have ever pulled the starter motor out, but having done it on various other cars over the years, I knew it would be more frustrating than necessary.

So, having made wedges for the rear wheels, fitted them, disconnected the battery, jacked up the front and secured him on axle stands under the jacking tubes, I rugged up warm and ducked under the front end, to be confronted with the first challenge. The old lucas M45G starter has a set of auxiliary contacts that bypass the ballast resistor when the starter solenoid is activated. The "modern" (90's?) replacement doesn't have this facility, so I consulted the wiring diagramme for inspiration. More on this later.

The next challenge was getting a 9/16 spanner on the lower bolt. Ultimately, I bought an extra long 9/16 ring spanner, which solved the problem, but not after multiple iterations of sockets, extensions, universal joints, etc, all ending in swearing, grazed knuckles and a general sense of malaise.

Strangely, the upper bolt was much easier, a long extension on a socket, straight under the right hand side exhaust manifold, and done! Great! 

The next issue was wrangling the motor out. The WSM recommends sliding forward and up, then dropping the starter out drive gear first, nose down. This proved impossible (for me, in the prevailing circumstances), as it seems the block drain tap is in the way. Ultimately, as the old starter was doomed anyway, I detached the tail end of the solenoid (2 screws and side cutters), destroying it in the process, but was able to get the cold, greasy, heavy wedge of eye level misery onto the floor. Joy.

The new starter is substantially smaller, lighter (and cleaner!). Refitting was "a reversal of the removal process", but for once, super easy and unchallenging. 3 hours of messing around getting the old one out was followed by 10 minutes of fitting the replacement.

The final issue was wiring. The 2 ring connectors (main feed from battery, power out to the rest of the car) are straightforward, both bolting to the main threaded input on the solenoid, but the 2 spade connectors (solenoid/start activation, and ballast resistor bypass) present another issue. Ultimately, as the new starter draws much less current than the old starter, thus less voltage drop, I settled on not connecting the ballast bypass at all. So far so good on this, however if cold starting ever becomes an issue I will have to fit a relay to re-enable this feature.

The new starter spins the engine very fast, and is much noisier than the old one, but feels solid and the engine fires up quickly on cold mornings. What more could I want?

Well, a 4 post car hoist, obviously! 

[Phil Nottingham]

Well done the new motor certainly is smaller. I use a long wobble bar extension to remove the motors.  The first time I did it 30 odd years ago I noticed the bolt had a screw slot which with a long wide blade square section driver undid easily


There is no need for a ballast resistor and 1971 car on omitted it. However the coil must now be changed to a 12v Hight output Lucas HA12 or the gold sports coil as the 9v ballast coil will soon burn out running at 12v if you have bypassed the ballast and if not the 9v coil may not start it a very cold/damp engine so easily as a 12v

[Mike’S-a-loon]

Hi Phil,

I haven’t deleted the ballast resistor, just the bypass. This means the coil doesn’t get an extra boost on startup, it is always running via the ballast.

[enigmas]

Well done Mike.
That poor old original Rover starter motor (based on the photo you posted) certainly does need to be put to rest. As for the Range/Land Rover reduction starter motors, I've been using them for decades now. The original one in my P5 Coupe saw 20 years and 300,000 kms and is now fitted to the P76 engine in the test stand. Due to the reduction gears in the starter motor it has no trouble spinning the 11:1 compression 4.4 litre V8 in my coupe. The current draw is also greatly reduced. I don't have a bypass ballast resistor in circuit in my coupe and use a 12 volt coil. It's really not required in a temperate climate, but Oregon in Winter may be a different story.

As an aside I still have the Factory P76 starter motor (designed for a 9:1 compression ratio P76 engine with a static ignition setting of 0° - 2°BTDC.) The original factory starter nose split after a short time of struggling to crank the engine. On LPG, the engine runs 12° - 14° BTDC when starting. There's no comparison between the torque output of the small reduction starter and the OEM unit.