The Triumph Dolomite Club - Discussion Forum

been looking at putting an overdrive box into the toledo, but i dont know what type to look for?

Will an overdrive box from a 1500 fit, and will i need the rear axle too. Also is a 'J' type okay to use, and what on earth is the difference between the three rail and single rail

yes a 1500 o/d box will fit, if you can find a good one....

Does the 1500 overdrive box have a 'tag' such as 'j' type, or anything like that. Just to aid the search

Also would a spitfire 1500 overdrive box fit, as a spitfire has turned up at a local scrappy

pandaselecta wrote:Also would a spitfire 1500 overdrive box fit, as a spitfire has turned up at a local scrappy

As far as I know, yes.

Three rail was used on earlier cars and single rail on later ones. The differences I've completely forgotten...
But from what I remember seeing on here somewhere, they're pretty interchangeable, you only need the corresponding drive plates in the clutch.

I could be wrong though. My brain is a little frazzled this morning.

pandaselecta wrote:Also would a spitfire 1500 overdrive box fit, as a spitfire has turned up at a local scrappy

yes. A lot of Shitfire owners raided Dolomites for their gearboxes, so it would be nice to see one being taken back. Just be carefull, most 1500 / 1850 overdrive boxes I've tried have had a slipping o/d unit.

The answer is yes.
The options are single rail or 3 rail. Both fit but the clutch driven plate needs to match the input shaft spline wise.

A 3 rail J type o/d box is very rare and only fitted as standard to the last mk4 spits, only a few of which had o/d cos it wanst cheap.

A dolomite (1850 engined one) wont fit. It has to come from an ohv car unless you fancy modifying the input shaft to fit and this involves machining.

You also need the o/d cross member and you may need to change the prop shaft if it doesnt fit. Ive fiitted o/d to non o/d dolomites and the prop was still okay.

If the box comes from a spit you will need a longer gearstick. Also if your Tolly is 3 rail you will need a dolly single rail tunnel I can help with most of these other bits bar the box itself.


Jonners

Three rail and single rail props are completely different as are their bearing arrangements. You can fit one to t'other but I cannot believe BL didn't change them for good reason.

A single rail gear lever will not fit a 3 rail box as the fastening is completely different.

All these bits are readily available via this borad to mix and match though.

pandaselecta wrote:been looking at putting an overdrive box into the toledo, but i dont know what type to look for?

Will an overdrive box from a 1500 fit, and will i need the rear axle too. Also is a 'J' type okay to use, and what on earth is the difference between the three rail and single rail

What everyone else said above, you want the box from a 1500 or spitfire.

Axles are all more or less the same (1300/1500/1850, sprint is very different), brakes vary a bit and there is a selection of different diff ratios (4.11, 3.89, 3.63 and 3.27). You don't have to change it but the others will all just bolt on. Other people have converted 1300 dollys and tollys to overdrive, dig up their threads and see which axles they used.

Props are different between three rail and single rail gearboxes, but are the same with and without overdrive.

I know I'm talking dolomites as opposed to toledos but there is no difference between props on single rail or 3 rail dolomite boxes.
The very early dolomites did have a different centre bearing arrangment but even my Wf5000 has the lastest type, so the early one is rare.

Jonners

Whatever you choose, the cost of converting a 3-rail Tolly to single-rail overdrive may make you think again. You need the 'box, a new clutch plate (and it is false economy replacing just the plate, so you may as well fit a new 3-piece clutch), the electrics extension piece, the prop, a matching speedo cable (possibly a speedometer as well), the mounting plate for the rear mount, the rear mount itself and, possibly, a gearbox tunnel; oh and the bit that secures the inner gearlever gaiter is different.

Oh, and if the overdrive slips (which late 1500 boxes are very prone to doing), you will have to fork out to have it reconditioned.

Having changed a 3-rail Toledo box to single rail (on 2 cars) you do have to change the prop, whether overdriven or not.

3-rail boxes tend to be weaker than single rail. 3-rail boxes have reverse gear next to first on the lever; single rail, reverse is next to third.

Sorry to be the prophet of doom but it is quite an undertaking to find all of the parts these days, let alone getting round to fitting it...

R

yes yes yes yes

to all of above. welcome to the world of gloria. financially viable?? hmmm, well gloria was resprayed on the cheap (family rate), subframe stripped, epoxy'd, rebuilt with poly bushes, spax, HL dash and wiring, custom stainless zorst etc etc, and stands me currently somewhere between 2 and 2.5k including the 1500 with o/d box courtesy of jod, and a load of his time too.

worth it? dont be daft, all totally a labour of love, but shes more driveable in modern conditions exactly as was intended, looks smart and will last for many more years to come, so to me, yes, worth it, but thats only because I love my gloria...

small irony as she was destined to be scrapped, and i was actually given the car as a free gift, and my sprint project of 5 yrs plus is still awaiting paint.