Posted by Nick Jones
on 4/25/2009, 12:03 pm, in reply to "Re: Opinions wanted! 4speed OD vs. 5 speed conversion"
80.229.165.96
The original gearbox with OD does have some plus points: It's compact, light and has great ratios. When in good condition it also has a nice change action and overdrive is fun (and practical on a long drive).
However, strength and longevity are NOT its best point. It is possible to get them built using TR7 4 speed/Dolomite 1850 internals and J type overdrive. If done with the right parts combination by someone who knows what he's doing, they can be pretty strong and retain all the virtues listed above. If you are in the UK I can suggest some candidates.
The Ford type 9 is a fair bit stronger, is quieter usually and has a nice change. The ratios are not so good - 1st and second are much lower especially if the gearbox is sourced from a 4 cyl car. You also need to watch the gearstick position as it will tend to come out way too car back unless the gearbox is modified (reasonably easy).
Toyota W58 (ex-Supra) is another option but more work or more expensive dependent on your approach. Better ratios than the T9 though and you won't break it with a Triumph engine. This is what I have in my Vitesse and I like it. I find 5th and acceptable substitute for OD.
There is a previous (lengthy) thread on this subject on this forum and also on the UK Club Triumph Forum.
Hope this helps
Nick
--Previous Message--
: From a practical standpoint, a conversion
: makes the most sense.
: Personally I think TR gearboxes should
: say "stanpart" on them but
: keeping these things alive is getting
: difficult, especially if you use it
: real hard. Some spares are hard to
: find, and quality is a big issue when
: it comes to gearbox & overdrive
: parts.
: If your box isn't too trashed, it may
: be worth saving.
: There is also the option of getting a
: rebuilt unit from one of the suppliers.
: O/D is nice to have, and works well as
: an intermediate gear between third
: & top. Although it doesn't provide
: a huge ratio difference between 3 &
: 4, it saves a manual gearchange, for
: those short upshifts to top.
: JMHO
: Glen
:
:
: --Previous Message--
: Hi...I have a vincent hurricane based
: on
: a GT6. The engine is 2litre straight
: six and gearbox i think is the d-type 4
: speed OD from the original. My current
: problem is that the syncro on 2nd has
: gone and it keeps popping out of gear
: along with many other performance
: issues with the box. So my choices are
: to get a full recon on the original box
: which means I would get to keep the OD
: and historic accuracy of the car
: (though bearing in mind it is
: effectively a kit-car based on the
: Hurricane conversion years ago!!) or I
: put in the stronger Type 9 gearbox used
: in the ford sierra and capri...which is
: a common conversion for gt6 and gives a
: 5speed transmission in place of the
: OD...
:
: The type 9 seems the obvious option in
: terms of performance, noise,
: durability, fuel consumption etc, yet
: part of me loves the excitement of
: driving with the OD!! Am I being
: irrational, should I go with the type
: 9?? does anyone have any experience of
: either? I dont want to miss out if the
: type 9 is so much better, but i dont
: want regrets either after spending so
: much on the conversion!!
:
: Thanks...
:
:
:
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