Forward facing (in cab) starter dog

[Howard Wright]

Hi All

My van has a forward facing (in cab) starter motor that turns well and cranks the engine smartly at 6.4 Volts. However it will only do that if the starter pinion return spring is so loose as to be ineffective. If I tighten this spring up to hold the pinion it simply won’t fire forward. 

The problem I hear you ask….with a loose spring the pinion rattles like a snake!

I have an earth return direct to the battery and as mentioned the starter turns the engine well so I don’t think this is due to a lack of electric power.

Anyone had the same problem?

Cheers

Howard

[Nick Turley]

Howard it is worth just checking the starter motor commutator, some folks clean out between the segments which makes the motor run slow.
If there is doubt, skim the com so that mic is level with the surface of the copper. It should then do the job as you wish it.

[Howard Wright]

Howard it is worth just checking the starter motor commutator, some folks clean out between the segments which makes the motor run slow.
If there is doubt, skim the com so that mic is level with the surface of the copper. It should then do the job as you wish it.

Hi Nick,
I’m ahead of you, commutator was skimmed a few weeks back.  The only reason I can think is causing the problem is that the pinion is very loose on the helix. Wear perhaps?

Cheers 

Howard

[Dave Mann]

I've had this happen when I've installed new pinion retaining springs and I removed the starter wound he pinion out of the spring and it worked OK, checking it later the pinion was held by the spring but not fully back right into the spring.
I came across one starter which had the commutator segments seriously undercut, I skimmed the commutator which didn't remove the undercutting and tested it, the commutator resembled a Catherine wheel so I skimmed the commutator to remove all the undercutting and the Catherine wheel effect was no more. The moral is do not undercut starter commutators.

[Howard Wright]

Thanks Dave

Good to know I’m not alone. The pinion acts just like yours, not quite returning to the full back position unless the pinion spring is pulled open.  I’m increasingly thinking that the problem is down to the pinion being very loose on the helix. Not sure why this would affect it but it would cause the very loud rattle!

Cheers 

Howard