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RE: TR3A Overdrive

To: <triumphs@autox.team.net>
Subject: RE: TR3A Overdrive
From: "Randall Young" <ryoung@navcomtech.com>
Date: Tue, 3 Sep 2002 18:39:26 -0700
>        I have a '59 TR3A with no overdrive.......What do I have
> to do or add
> to convert it over to overdrive ?
> If it can be done.......
> I thought I read something earlier about a TR4 Tranny
> switch.......How costly

Ron, by far the easiest thing is to find an OD tranny with A-type overdrive
from anything from a post-50K TR3A though a (roughly) 1973 TR6 and drop it
in.  There are a few minor changes required, but nothing major.  Here's the
ones I can think of offhand (some depend on just which tranny you find) :
. Add relay, wiring, switch on dash.
. Change speedo cable, reroute (takeoff on OD is on opposite side)
. Swap tranny front cover from old transmission (if new one is 4-synchro)
. Drill new holes (or elongate existing ones) in crossmember (4-synchro
only)
. Longer studs, bolts between engine block and tranny.
. Install TR3 type throwout bearing (like your old one, but use a new one
please).
. Use TR3 type shifter from old tranny

That's all I can think of ... BTW, some of the UK vendors sell used/rebuilt
OD trannys taken from newer cars, try Rimmer's during their summer "free
shipping" offer.

Of course, it's possible to buy an A-type and add it to your existing
tranny, but it's a complicated, expensive proposition.  You'll almost
certainly have to find the correct mainshaft separately, and it involves a
complete teardown of the tranny.

One other thought, several people are now selling conversions to a Toyota
5-speed tranny, where 5th gear is nearly the same ratio as the original 4th
OD.  One such is Herman van den Akker, whom you can email at
handhvan@msn.com

Randall

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