The Triumph Dolomite Club - Discussion Forum

Hi, can anyone advise. I have acquired a 1980 1300 dolomite that has a noisy rumbling when idling from the gearbox (I think) and a loud knocking in the first 3 gears but goes away in fourth.
After making some enquires I was told it is probably layshaft gears or something.
My question is I have a good engine and gearbox from a 1300 Toledo, can I exchange the Toledo gearbox being one is single rail and the other 3 rail or will the Toledo engine and box fit straight in.
Thanks in advance.

You can swap the gearboxes, but will need to swap clutch plate and propshaft too (different gearbox input splines and overall gearbox length)
However, a good non-od gearbox should be pretty cheap to buy and would be an easier solution. Unless the tolly box is a known good one.

engine is the same between both cars.

Hi thanks for the quick reply, as I already have the toledo engine and box which is good and still mated, would it be feasible to just change the whole unit over. Will propshaft need to be changed as well.
Thanks

It will work mechanically but the tunnel is different between single rail and 3 rail cars.

The boxes are the same length....prop shaft and mounting wont be an issue. As has been said, the splines on the input shaft will be different,
so the clutch will need to change too. I would also keep the clutch hydaulics with the gearbox. They shouldnt be incompatible but I have had issues
in the past.

I would though rather source a known good single rail box. A 3 rail box will look wrong in a dolly 1300....spit 1500's and midgets mean a plentiful supply.

I may even have one if you want me to look...

Not worth rebuilding sadly....

Jonners

Jon Tilson wrote:It will work mechanically but the tunnel is different between single rail and 3 rail cars.

The boxes are the same length....prop shaft and mounting wont be an issue. As has been said, the splines on the input shaft will be different,
so the clutch will need to change too. I would also keep the clutch hydaulics with the gearbox. They shouldnt be incompatible but I have had issues
in the past.

I would though rather source a known good single rail box. A 3 rail box will look wrong in a dolly 1300....spit 1500's and midgets mean a plentiful supply.

I may even have one if you want me to look...

Not worth rebuilding sadly....

Jonners

That would be great many thanks.

Single rail in a Midget Jon

Worth checking the gearbox lengths. My experiences are much greater with spitfires, and I know a spit 3 rail box is about 3" shorter than a single rail. And AFAIK the same applies to dolomite/toledo.
i do know that a 3 rail od box is the same as a single rail od, and a single rail od is an inch longer.

Didn't know the tunnels were different though. Stick is in the same position I think

Clutch slave should be the same. Only the coil spring clutches use a different slave

Your original problem is a chpped tooth, either on the first motion shaft gear or the front cog on the laygear cluster and, as Jonners says, repair is not a cost effective option.
Using the 3 rail box (with or without the engine) will necessitate changing the prop (which I guess you don't have) unless you put in a 3 rail with O/D from something like a MkIII Spit
As the others have said, single rail non o/d boxes are easy to come by and relatively cheap, why make life hard for yourself?

Steve

Sorry if my post was ambiguous...

Yes Midgets do indeed have single rail boxes....and lockheed slave cylinders....

I'll have to bow to knowledge on 3 rail ohv boxes length wise...my spit 1500 is single rail o-d and thats all Ive ever worked with.
On a dolomite the single rail and 3 rail boxes are the same length, but the tunnel and tray are different between single rail later and 3 rail early versions.

Jonners

Hi Guys thanks for all the advice, I will try to source a single rail box. One has appeared on Ebay from my town and the guy says it will fit a midget or 1500 spitfire, but is not sure about a dolly.
Thanks

That will do the job and you can easilly swap your gearstick.

Jonners