Re: Overdrive You Say?

[Doug Rasmussen <76075.2276@domain.elided>]

Mark wrote:
>Does there exist an overdrive unit I can fit to my T19/D20 Scout?  

Seems like I read of an overdrive that bolts onto the rear of the 
Dana 20 transfer case.  Who makes it?  What cost?  What ratio?  

Anybody know of these ...ever driven one?  Tell all!
Thanks!   Mark <

Mark,

  Yes, such an overdrive does exist.  I have one.

  It bolts on to the rear of a Dana 20.  Looks like about a 10 minute bench
installation.

  The going rate for these is around $400-500.

  Mine came out of a '70's Wagoneer (?),  the previous owner had it
installed by a 4x4 shop when he bought the rig new.  It has a "W" in a
circle.  I was told this is a Borg-Warner unit, or I should say a Warner
unit.  Possible before a merger of Borg & Warner.  At least that's what
another owner told me.

  I don't remember the exact ratio.  I calculated it once by counting turns
of the output shaft.  As I recall, with my 3.73 gears, it would become an
effective ratio of something like 2.4 !

  The unit only works in 2WD.  It has an electric solenoid & centrifugal
switch so it won't kick in below a certain mph.   You pull out a dash
mounted cable and as soon as the output shaft reaches the correct rpm
(vehicle mph) the o/d kicks in.  Internally it uses a Sprag (sp) clutch so
you don't have any compression braking.

   To install the unit the stock driveline has to be shortened 10".  I've
held off on installing it cause I don't feel like shortening my brand new
driveline.

  Doug