13/60 overdrive advice please

[Hammy]

Would like to add an overdrive gearbox to my 13/60 but keep the engine the standard 1300, the problem is I've no idea which type to use, now come the questions........
1.which gearbox should I look at getting
2.which differential would be best 3.89 or 3.63
Any other advice gratefully accepted
Thanks

[Mark Hammond]

MKlV Spitfire with D Type overdrive easiest option with Vitesse non overdrive propshaft and a round flange at the gearbox end of prop to match that on the 'box.  You'll need an angle drive for the speedo and a longer speedo cable (Vitesse) and the necessary mounts (Vitesse).  I'd leave the diff as it is 4.11 is ok with 1300 and O/D.

M.

[Nick Jones]

As above really.  You can also use a 1500 Spit / Dolly 1500 gearbox but that also needs a different clutch plate (fine spline) and a shorter (by 1") propshaft compared to the above.

Agree that the 4.11 diff is fine though it would pull the 3.89 if you had other compelling reasons to fit one.

Nick

[Hammy]

Sorry Nick if I've misunderstood do you mean an overdrive gearbox or a standard 1500 dolly/spitfire?? The reason I want to upgrade is to give it better cruising speed and not feel like I'm thrashing it over 50mph, thanks for the help so far

[Mark Hammond]

Single rail 'box with overdrive needs a further inch lopping off the prop (Vitesse non O/D prop) or without overdrive an inch lopping off the standard prop.  Single rail 'box uses J type overdrive.  IMHO the single rail route isn't the way to go.  Not as nice gearbox and no where near as nice a gearchange as 3 rail.  Just my opinion though.

Mark

[Clive]

As above, just fit an od box and keep the diff. That is what in ran in several heralds, and indeed a 4.11 in my Toledo (with od) all happily able to cruise at above legal speeds on the motorway with no drama.

All mine used j type, but I would use whichever became available and was a good unit.
Bear in mind ALL the parts you will need.
Overdrive gearbox with od attached
Correct length propshaft with ends to match your od and prop
Either od gearstick with switch on top or column switch
Angle drive
Longer speedo cable
Mounting plate and rubber mount
Inhibitor switches/mechanism (often missing off 3 rail boxes)
Dolly 1300 clutch plate if a single rail box

My choice would be a 4 synchro 3 rail box, a bit easier.

[Freebird]

1218 wrote:

  Not as nice gearbox and no where near as nice a gearchange as 3 rail.  Just my opinion though.

Mark

Not one I share though Mark - each to their own and all that.

Got 3 rail in the Vitesse and single in the Spitfire which I find more pleasent to use. Neither are bad though. Just the 3 rail (mine anyway) puts 3rd quite a long way to the right and 4th sort of diagonally down and to the left, you soon get used to it though. Plus the linkage bushes are prone to wear and new ones are of rubbish quality. The Spit 'box is lovely and direct - snick, snick, snick.........

I prefer the Vitesse type OD switch on the dash rather than the Spitfire/Dolly type gearstick switch too, when we fit the OD 'box to the spitfire I might rig a dash or wheel mounted switch.

Glen.

[Steve P]

I run the single rail with j type od in my Herald 1360 with a 3.63 diff and it pulls fine and will cruise at 80 easily.

Twin carbs and a 4-1 manifold and Vitesse system though.
S

[Nick Jones]

8550 wrote:

Sorry Nick if I've misunderstood do you mean an overdrive gearbox or a standard 1500 dolly/spitfire?? The reason I want to upgrade is to give it better cruising speed and not feel like I'm thrashing it over 50mph, thanks for the help so far

I meant the overdrive versions.  Both the Dolomite and Spitfire 1500 use the later "single rail" version of the  gearbox (can be OD or non OD) with J-type OD where fitted.  These can also be fitted to a Herald with the provisos mentioned above.  

I don't agree with the traditional view that the three rail gearboxes have the sweetest change.  The single rail box I had in my Herald had the sweetest change of any Triumph I have owned and no stupid bushes to fall to bits at regular intervals.  The single rail boxes are bit stronger also.

Nick

[Hammy]

Thanks for clarifying that Nick,thanks for all the good advice everybody,off to ebay now to see what I can find!!!! Will be back for more help later when my Xmas money runs out,..........