Starter motor not turning engine

[1938austin7]

Hello,

I have a starter motor that would spin, but not engage the engine.  It was working fine a few months ago but the last time I tried to start the car (before pulling the engine apart) it wouldn't turn the engine at all.

Anyone had a similar problem, and solutions would be greatly appreciated.  I want it working again when I get the engine back together. (1938 Austin 7)

Thanks

Geoff

[Matt_Harnden]

Hi Geoff,

If the starter motor spins but doesn't turn the engine then this is most likely caused by a sticking dog gear.

When the starter is powered it is supposed to spin a dog gear to mesh with the flywheel gear. Centrifugal force makes the two mesh when the starter is engaged.

What you need to do is to take the starter motor off and check that the starter dog gear is clean and does not stick. You can use a very, very small amount of light oil to ensure it is thrown out when the motor spins.

Reasemble the starter to the car and then everything should be ok.

Good luck.

Matt

[Derek Sheldon]

Knackered battery, have had two go down in as many months. Working fine only a few weeks before

[Louis Henry]

I was astonished how much an earth strap from the starter to the body improved it.

[1938austin7]

I was astonished how much an earth strap from the starter to the body improved it.

Thanks all,

As it is out of the car I will do a test on the weekend and see if the gear is stuck.  Cheers Geoff

[1938austin7]

I was astonished how much an earth strap from the starter to the body improved it.

Thanks all,

As it is out of the car I will do a test on the weekend and see if the gear is stuck.  Cheers Geoff

I tested it the other day with body of the starter resting on the battery and the gear flung out as far as it could.

Based on the earth comment, I am assuming corrosion on the battery terminal that I discovered when I dismantled the engine may have been enough to stop it working properly.

Fingers crossed.  I am hoping to get the car back on the road in the next couple of weeks.

[Ian Wegg]

I was astonished how much an earth strap from the starter to the body improved it.

Four years later this has saved me a bit of work. Thanks for that!

[Bob Culver]

An accumulation of dirt can gum up the engagement. For this reason many books recommend no lubricant but as above I favour thin oil cleaned as necessary. 
Not likely to change in place but the grip of the retainer clip is quite critical. Easily bumped. Too tight and the pinion is reluctant to free and too loose it can wander into mesh underway with curious musical ting ting sounds until it resettles.