The 32% figure that you state is consistanst with my calculations of
planetary gear ratio on 2 D types that I have at home (31.67%).
I think I should note however that both of these OD units were burnt up
behind an alpine engine shortly after the OD was rebuilt.
I believe that the additional load placed upon the gears in the 32% OD units
causes the planet bearings to fail when used with the higher output Alpine
engine.
Anyone know what cars used the 32% OD ratios?
Or where I can get some 25% OD gearsets?
Jarrid Gross
----------
From: T Wiencek
To: Message Alpine
Subject: Overdrive Trivia
Date: Friday, December 06, 1996 7:31AM
Subject: Time: 9:10 AM
OFFICE MEMO Overdrive Trivia Date:
12/6/96
I found the following in a data sheet from the Rootes Work Shop Manual (W.
S.
M.) 124 dated December 1959-
It should be noted that the overdrive unit number for Laycock De
Normanville D-Type, which consists of three sets of figures seperated by
oblique strokes, is made up as follows:
First number: Percentage change of drive ratio, e. g. 32% or 25%.
Second Number: Type Designation
Third Number: Serial number.
I think all Alpine OD's were 25%. Is this true? My Late 50's Singer book
lists a 32% OD. Does anyone know of any other OD ratios? Thanx. Tom
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