Gear Box Options

[mickeytwonames]

Just completed an 800 mile trip with my now well-running 1956 split screen saloon.
Last year the engine was changed from the original 948 cc to a 1098 cc engine.
However,as I had no option at the time, I used the original gear-box.
If I want to change (up-cycle) it what options do I have?
For example, is the a five speed box I could use?
Most grateful for the usual raft of helpful answers.
If anyone has one for sale - I would be keen to know.

[bmcecosse]

Your easiest improvement will be to change the rear axle ratio to make for easier cruising and better fuel economy. Your car will have 4.55 ratio - even the 4.22 would help, but a 3.9 would be even better. Budget ~ £800/1000 for a 5 speed.

[MrIan]

I have a 5 speed Sierra gearbox in my 1959 minor but even so I'm thinking of changing the diff as first is almost useless and even in 5th it feels like it needs more.

[mike.perry]

The original engine in a 1956 split screen would have been an 803 which may well have been replaced by the 948 which you have in turn changed for a 1098. If by original gearbox you mean the 803 box with the long gear lever then the 1098 box together with a 4.22 diff would be a vast improvement. Before fitting the 5 speed box check to see what diff is fitted. The original 803 5.375 diff will be too low for a 1098. You will also need to change the speedo

[irmscher]

And don't forget the 5 speed housing will have to be modified plus the prop cross member clutch etc

[John Naylor]

I paid £500 for a 5 speed Sierra box and 2nd hand fitting kit (advertised on here) but have yet to fit it. With 1098cc and 4.22 diff I wanted to be able to do 60 on Motorways without too many revs (and noise) and probably could have done this more cheaply and easily with a 3.9 diff but maybe when I have extracted a little more power I will go for the 3.9 diff as well.
When I uprated my Frogeye, many years ago I fitted a 1098 (cost £8) and added a later baulk ring box (cost £2) and the gearbox was as much as an improvement as the engine.
John

[mickeytwonames]

Many thanks for that advice - how do I check which diff I have?

[bmcecosse]

The diffs are all the same - only the final drive gears change.... Basically - you jack one rear wheel up, mark the tyre with chalk at 12 o'clock - then turn the prop shaft and count how many turns till the mark comes round to 12 again.. And then multiply by two to get the ratio. (that's because the diff makes the wheel turn twice as fast when the other is not moving..)

[mickeytwonames]

Thanks for that tip
I have a spare (new) MOWAG diff that has the letters
BTA 547 9/38 stamped on the drive ring

I suspect it's a 4.22

As I have it and now have a 1098 engine where I once had a 948 should I swap it for the 4.55 that is on the car?
Lastly, how much workshop time do you think a swap might take.

[bmcecosse]

Yes the 4.22 is a better option if you have a 1098 engine. Although a 3.9 would be better! It takes a couple of hours to change a diff - depends how much time it takes you jacking up/removing wheels etc... It's not a difficult job...just make sure you have oil and gasket in stock before you start.

[philthehill]

May be worth a consideration:-
With the Ford Type 9 gearboxes getting ever dearer it may be time to re-appraise/consider/re-consider the Ford 4 speed box which is now plentiful and cheap.
You can have all the benefits of a Ford gearbox at a fraction of the cost except for the 5th gear.

http://www.ebay.co.uk/itm/ford-type-E-r ... 35e7f0a4bb

The gearbox ratios are much better than the Minor ones (especially if you find and fit a Rocket Box) and you have the benefit of synchro on first gear.
Before the Ford Type 9 was widely available the Ford 4 speed box was the way to go.
Make sure that if you decide to go the 4 speed route get a box with the removable bell housing.
I had a test drive in the CS Auto Classics (CSA) 1098cc Traveller fitted with the 4 speed box and it was a pleasure to drive.
It convinced me to convert my Minor to the Ford 4 speed box (using the CSA conversion kit) which I later converted to full Quaife Clubman spec.
If you decide to go to Type 9 at a later date you can with little extra expense or extra effort.
I do have data sheets on the various Ford gearboxes if required.