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Re: Rear Gear Tooth Count 4 Ratio?

Subject: Re: Rear Gear Tooth Count 4 Ratio?
From: (Rick Morrison)
Date: Tue, 05 May 1998 19:37:42 EDT
On Sun, 03 May 1998 14:41:13 -0600 Charles & Peggy Robins

>It doesn't have to come out even either. 
 A properly designed ring and pinion set will never come out to an even
number, such as 4:1. 
The  reason for this is so that during it's rotation relative to each
other, any one given pinion tooth will contact every ring gear tooth,
whereas with an even ratio, such as a 40/10 gear set (4:1 ratio), tooth
#1 (for example) on the ring gear would only make contact with the ring
gear in 4 points. 
 The theory behind all this is that any minor machining imperfection in a
gear tooth would be burnished back by contacting all the matching gear,
thus evening out the wear and increasing longevity.

 At least that's the story my auto mechanics teacher handed out in High
school, but it makes a bunch of sense when you think about it.
Rick Morrison
74 Midget

 Look at our MGB.  Standard 
>is ~ 3.909 = 43/11.  That's why you  get things like 4.22:1.
>  Cheers,
>  Charley Robinson
>  Kerrville, TX, USA
>  NAMGBR  8-3530
>  `69 B Roadster

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