Ring Gear for 4A

The 4A, 4AB, 4AC, 4AD cars, including the SM 1500 Roadster and SMX
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2001f4s
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First Name: Scott
Location: Chicagoland

Ring Gear for 4A

Post by 2001f4s »

I discovered that the ring gear on my fly wheel is just a mess and needs replacement. Is anyone aware of a source for a ring gear. Mine has 112 teeth.
Is there an alternative that will work well on the 4A.

Thanks for looking and for your input
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Paul Bouchard
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Re: Ring Gear for 4A

Post by Paul Bouchard »

Ring gear usually wear in two spots 180 degrees apart from each other. They are a press fit so you can try to take it off and rotate it by 90 degrees and/or flip it around front to back. Just check to see if the teeth are the same profile on the front and back.

Paul
Paul Bouchard

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1948 A Series Roadster
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1935 Le Mans Super Speed Model

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bitsobrits
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Re: Ring Gear for 4A

Post by bitsobrits »

Paul,

Um...I don't get the "remove the ring gear and rotate 180 degrees". Isn't that the same as just rotating the engine by 180? The starter pinion and ring gear do not engage at the same point, over and over, due to the large variance in diameter between the two. Every time the starter is engaged, the starter pinion will engage at essentially random points on the ring gear.

As for the "remove the ring gear and flip it around", that could work.
Steve W
Singer 4ADT
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mikeyr
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Re: Ring Gear for 4A

Post by mikeyr »

you are right, the ring gears do wear all around. But they do tend to wear in a few spots as the engine when shut down tends to shut down in the same spot in the rotation. Not every time of course and but if you look closely as a well used ring gear you will see 2 or 3 spots that are more worn then the rest of the gear, trying to rotate the ring gear though I find is a waste of time (but I only tried it once) because the engine will stop where it wants to. I read about this in Skinned Knuckles magazine years and years ago and I tried it on my 4AD, it helped but it really was not a solution.

Flipping the ring gear around so the unused side of the gear is now facing the starter pinion is something I have had good luck with as in its worked everytime.
Mike Rambour. Site Administrator
1953 Singer 4ADT (sold), 1934 Singer 9 Le Mans, 1934 Singer 1 1/2 4-Seater Sports (sold), 2009 BMW K1300GT
indian301
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Re: Ring Gear for 4A

Post by indian301 »

The ring gear should tap off the flywheel, but You will need to heat it up to install it again.
2001f4s
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First Name: Scott
Location: Chicagoland

Re: Ring Gear for 4A

Post by 2001f4s »

Mine seems to show damage almost 270 degrees around, but I think what Paul describes with flipping it over will work for mine. Thank you
GuyBevan
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Re: Ring Gear for 4A

Post by GuyBevan »

Hi,
I purchased the correct ring gear for my Singer 4a from Magnum performance Products. 35 Marni St. Dandenong South, Victoria Australia
Phone +6139706 6554
www. magnumperformance.com.au

The sell on Ebay Australia for $A 195.00
Part number is 112TRG#226
112 teeth 288mm outer
267.3mm inner
Michael is the contact
They do not show this part no. on their online store but they have it
Hope this helps
Guy
2001f4s
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Joined: Sun Mar 24, 2013 3:22 am
First Name: Scott
Location: Chicagoland

Re: Ring Gear for 4A

Post by 2001f4s »

Guy,

Great information. Thank you much for that information. Sent an e-mail inquiry to them.

Thanks again. Not likely I would have found them without your work
Scott
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