Whenever this question is asked, and answered, everyone seems to always forget
one critical part that is NOT internal. The rear extension on the standard
gearbox is replaced with an overdrive adapter that goes between the overdrive
unit and the main gearbox casing. Now where are your going to find an
overdrive adapter unless you have an overdrive gearbox to start with? (Not
even shown in a Moss catalog.) I admit that I've not actually tried to find
this piece for sale, but I have a strong suspicion that it isn't available
standing alone.
Bill
Trevor Boicey wrote:
> Enrique Claure wrote:
> >
> > Hi list, is it possible to add an overdrive unit to a standard 4speed or
> > are the gearbox and overdrive setup a single unit?
>
> It's theoretically possible to add overdrive to a standard
> 4 speed, but you have to change some internal parts in the
> tranny. (the mainshaft being the main one, it has to be a few
> inches longer)
>
> The problem is that the parts you need to put in are
> non-wearing parts, so not generally made as spares in
> any real volume, so you can't just call up a parts dealer
> and get one.
>
> The usual and generally only way to get these parts
> is to take apart an overdrive tranny.
>
> So generally, it's almost always easier to just put
> in the gearbox and overdrive from an OD car. Unless you
> have a freshly rebuilt box, and you source a worn
> out box, and you want to swap a lot of parts. ;>
>
> --
> Trevor Boicey, P. Eng.
> Ottawa, Canada, tboicey@brit.ca
> ICQ #17432933 http://www.brit.ca/~tboicey/
> Now if you'll excuse me, I'm gonna get my drink on.
|