Half shaft difference

[darren1camper]

Is there any difference with the axle and half shafts from a 1957 ,and a later type 1098. I'm putting a midget 1275 engine into a 1957 4 door and wondering wether I should put 1098 half shafts in and a midget diff?

[mike.perry]

Definitely fit the Midget gearbox and diff. I think that the Minor half shafts are the same.

[bmcecosse]

Obviously shafts from a 57 car have seen a bit of service......although could argue it would be 'gentle' service. Later shafts may be less stressed - but physically they are same dimensions......however Spridget shafts are shorter, if that was what you were planning.. . The final drive from a Spridget will be better suited to a 1275 engine.

[darren1camper]

Thank you for your help as always, I, going to try and find a 3.9 diff at a reasonable price I allready have a midget gearbox, thanks once again for your advice.

[bmcecosse]

The 'diff' is the same over all the models - only the final drive gear ratios changed....

[chrisryder]

The 'diff' is the same over all the models - only the final drive gear ratios changed....

Oh god, not another 'adage' of yours to live with.

What happens when the chap (or anyone else for that matter) reads that and assumes that all diffs have the same ratios? You know what he means! Just like 'shocks' meaning 'dampers'...

[bmcecosse]

Correct terminology is everything Chris....you should be grown up enough to know that by now. The differential is the part of the final drive that allows one wheel to turn more quickly than the other......it just happens to have the final drive gears attached...., and yes - they are available with various reduction ratios. And I do believe you know what Dampers are by now...I've been over it often enough! 'Shocks' are what you will get if you grab hold of the HT leads on a damp day.... And no - I don't suggest you try it.......

[philthehill]

The trouble is that one mans meat is another mans fish!
The terminology used is different dependent upon your point of view and 'experience'.
For example reference to dampers and shocks (shock absorbers) both the same thing in most peoples minds! The genuine BMC manual calls them shock absorbers and dampers.
I personally would like to see no dumming down and the correct terminology used in all posts but I know that is not going to happen.
If a post is started with a alternative name for a part/item and it is clear what is meant in the name I have no problem with that but for consistency that name should be used in all other posts relating to the subject in hand. If there is no clarity in what is meant by the alternative name it should be pointed out and the correct name used.
"You can please some of the people some of the time but you cannot please all of the people all of the time".

[bmcecosse]

[darren1camper]

So any pros and cons to what differential ratio I should go for as 3.9 seems to be scarce at reasonable price.

[MarkyB]

Do you know what is fitted now?
4.2s will be much cheaper and 3.7s even more expensive.
3.9 will suit a 1275 very well.

[philthehill]

Yes the 1275cc Midget differential (3.9 to 1) assemblies do seem to be a bit pricy at the moment!
There does not seem to be any available for the Wolseley 1500 (3.9 to 1) or Riley 1.5 (3.727 to 1) either. The 3.727 to 1 of the Riley would be too high a ratio even with the 1275cc Midget engine.
You could go for a 4.2 to 1 differential assembly which is a bit cheaper and will cut the revs down a little compared to your 1957 Minor axle (4.55 to 1) if still original spec.
There is a low mileage 4.2 to 1 differential assembly with the stronger BTA carrier/housing on 'e' bay at the moment Item No 231051494046 at a Buy It Now price of £99.
Just found a 3.9 to 1 diff on 'e' bay for £145 Buy It Now price. Item No 121171713603.
Another 3.9 to 1 diff on 'e' bay for £170 Buy It Now price. Item No 181217571216.
Good luck

[darren1camper]

Thank you for your help, the axle is the original and I suspect the diff is the original. You have been msg helpful I just need to keep an eye out on a 3.9 reasonable priced. Thanks guys

[mike.perry]

From experience the 3.9 diff is well suited to the 1275 in a Traveller, giving a good balance between acceleration and cruising speed. However be aware that some diffs have the oil filler on the diff casing and some on the axle casing, you could end up with two filler plugs or none at all.
You will also need to uprate the 7 in front brakes. The ££s are mounting up

[bmcecosse]

My 3.7 final drive works nicely in my modified 1098 (bar the engine backfire discussed elsewhere... ) - I would expect a decent 1275 to be even better! Assuming 4 speed g'box of course.. Yes - they are getting to be more expensive, but consider it to be an investment - the value can only go UP! Mine has trebled in value in v few years.... And - there happens to be a Mini speedo with TPM 1248* which gives PERFECT mileage and speed readings with a 3.7 final drive, and 155 X14 tyres.
Edited to change 1298 to the correct figure of 1248..

[darren1camper]

Thanks bmcosse much appreciated, so I have another option of diff then, never thought about changing the speedo.

[bmcecosse]

Grrrrr.

[darren1camper]

My 1957 car has a 948 cc engine any ideas what the standard diff was used I.e ratio

[chrisryder]

My 1957 car has a 948 cc engine any ideas what the standard diff was used I.e ratio

4.5:1

[bmcecosse]

Same 'diff' as all the others, but fitted with 4.55:1 ratio gearing........