Dolomite 1850 overdrive box

[martinclan]

Someone has offered me a Dolomite 1850 overdrive box.
I am sure I read somewhere that this is an easy swap for the standard gearbox (B series engine). Is that correct or am I imagining it?
Needless to say I don't remember where I saw the original info

Cheers Robin

[MarinaCoupe]

Yes ish, you may find that the input shaft isn’t long enough, but depending on the 1850 input gear to layshaft design (compare the number of teeth and the diameter), it may be swappable with the one from your 1800 input shaft.

I fitted the Spitfire 1500 gearbox and overdrive in my Coupe many years ago (essentially the same gearbox as the Dolly 1850), I had to swap the input shaft. You will need to raise the line of the transmission tunnel by 50mm (2” approx.) as the gear selector mechanism is on top of the O/D gearbox rather then below the line of the top of the gearbox. You may need to ‘relieve’ the nearside gearbox bracket to allow the O/D solonoid to fit, I used a little heat and a big hammer.

The Marina bell-housing will bolt straight up to the 1850 gearbox. You will also to fab up a rear gearbox mount and wire in the overdrive and reverse, 1st & 2nd gear lockout mechanism.

You will need a suitable speedo cable as the Marina one won’t mate to the Triumph gearbox.

[martinclan]

Thanks Chris. Just the info I needed although in the end I didn't go ahead with the purchase as it turned out the internals of the box were all literally in a (cardboard) box!
Cheers Robin

[MarinaCoupe]

They aren’t difficult to rebuild, as long as each and every part is there, otherwise you could be bu**ered as some parts are getting very rare.