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+--- Thread: A7 Starter motor - hair spring? (/showthread.php?tid=9699)
A7 Starter motor - hair spring? - Larry Tucker - 14-11-2024
Hi all, had some issues with starter on my Ulster rep at Lakeland trials. Think I've rectified the issue (poor connection) but when I removed starter motor yesterday I'm now wondering if it should have a "hair spring" to help the pinion go back into the resting place and then be held in place by tension of the 2 clips on side. I bench tested it and it does move quite freely but I think it should have a spring to help pinion go back although there is very little shoulder to hold it in? I think it should go where pen is indicating.
The alternative method I guess would be for flywheel to throw it back when it starts and tension on clips holds it there?
I'm not that familiar with starters of this age!
any ideas if it should have a hair spring and if it does where can I get one!!!?
Its a CAV and only other number on casing are. 10402 and 531
RE: A7 Starter motor - hair spring? - Robert Leigh - 14-11-2024
I think at that time the idea was that the increasing speed of the flywheel when the starter disengaged would push the pinion back along the scroll and the spring steel parking spring would hold it until the next time the motor was energised, when the motor would obviously turn faster in relation to the then stationary flywheel . It all relies on the inertia of the parts involved.
RE: A7 Starter motor - hair spring? - Howard Wright - 14-11-2024
Hi Larry
I’ve never seen a spring here in the half dozen starters I’ve had through my hands.
Cheers
Howard
RE: A7 Starter motor - hair spring? - Reckless Rat - 14-11-2024
Looks fine to me, however before putting it back on, check the relationship between the "at rest" pinion and the retaining clip. Sometimes it can be too loose and the pinion can work back up the bendix. There is no "hair spring" normally the action of starting causes the pinion to return to the at rest position.
The bendix and shaft shouldn't really be covered in oil. It is best left dry or lubricated if necessary with a bit of graphite dust.
RE: A7 Starter motor - hair spring? - Larry Tucker - 14-11-2024
All, many thanks for the quick confirmation.
I will clean it up too, Trials mud / grime loves oil!!
Cheers
RE: A7 Starter motor - hair spring? - Ivor Hawkins - 14-11-2024
I always clean the Bendix screw with paraffin…it definitely doesn’t need oiling!
RE: A7 Starter motor - hair spring? - Malcolm Parker - 15-11-2024
Hi Larry, I am sure your starter motor is fine. It stopped working last year and I renewed the brushes following which it worked very well. In answer to your question, the pinion is on a reverse thread so that the inertia throws it back up the shaft when the engine fires up. The two spring steel clips then hold it in place. If they loose some of their tension, the pinion will rattle back and forth making a distinctive tinkling sound as it touches the flywheel teeth. With the starter off the car, move the pinion forward and gently squeeze the two spring clips together with your fingers so they grip the pinion when it is at rest. That should cure the problem.
Hope you are enjoying doing the VSCC trials!
RE: A7 Starter motor - hair spring? - Larry Tucker - 15-11-2024
Cheers Malcolm, yes all is good, Trialling great fun.
didn't want to keep pestering you otherwise you'll think I'm expecting there's a lifetime guarantee with car.
Loads of people telling me to say hello to you when they see the car!
cheers