Diff Identification

[Declan_Burns]

Quite a good video Paul and it confirms what I was trying to state above. You may have the pre-load within spec without having reached the 140ft.lb torque. Even on the video they overshot the torque and had to do it over again. I did like their idea to use the shims on the outside of the carrier rather than between the bearings and the carrier. It saves having to pull bearings. I made a pair of set-up bearings to avoid that problem.
Regards
Declan

[paul 300358]

I think that I would have a supply of crush spacers before starting. Once you have over crushed one, I would want to have another go straight away, while I had a feel for it!!

I can also recommend the MED YouTube videos, there is one which explains the required work to convert a 1275 transvers block into a rear wheel drive.

[philthehill]

Paul
Could you please post a link to the You Tube Mini conversion as I am having difficulty finding the MED film.

Phil

[paul 300358]

Hi Phil
Have a look at https://www.youtube.com/watch?v=9sxy1pU ... _cNOfEoDay I think that's the one.

Paul

[philthehill]

Paul
Many thanks for the link.
I was aware that the conversion is doable but at a cost.

Whilst the MG Midget engine is not so common as it used to be they can still be found at what I consider to be a lesser cost compared to doing the Mini block conversion.

You will still require a 1275cc Midget crankshaft which in good condition is not cheap and the matching 1275cc Midget or Cooper S conrods.

That MRD MG Midget crankshaft is a nice piece of work.

I could not work out if that MRD rear oil would fit a standard crankshaft or just the MED crankshaft.

Phil

[alawrence10360]

So this is the one i have taken off which is standard i believe.
All was going well .Fitted the new diff.
Went to fit the prop shaft and found that the flange on the diff is distorted. Looking at it now , a blind man on a galloping horse couldnt of missed it but I did.
Decided to take the flangevoff the standard diff I had just removed.
I couldnt get the flange off that was fitted to the axle as the nut was too tight to get off in situ.
After I had swore at the dog , had a cry and a cup of tea I removed the diff I had just fitted , replaced the pinion flange and reffitted the diff.
The only problem I have now is I cant find the new gaskets I bought for the drive shafts...
Time for a pint I think

[alawrence10360]

Found my gaskets bot its strange to me that they overlap the rubber seal thats fitted
Also I put a litre of ep90 GL4 in and it still isnt full..

[philthehill]

The hub gasket is supposed to overlap the neoprene 'O' ring.

The 'O' ring is a secondary means of keeping the oil within the axle casing.

Originally the 'O' ring was not fitted but was fitted to later vehicles in an attempt to cure weeping half-shaft to hub gaskets.

Lightly grease the gasket before fitting. There is no need to use a propriety sealer.

Make sure you have the right thickness half-shaft gasket as the thickness has an impact on the lateral movement of the hub.

With the wrong thickness gasket at worst the hub can move in and out on the bearing, the bearing must be nipped tight in the hub.

When filling the axle with oil the axle must be level in all aspects/planes.

[alawrence10360]

Got the gaskets from ESM and there some mention of the thick ess being correct
I think the o es that were fitted were thicker
With regard to the fli g the car if o a level surfave in both planes
I can only assume the casting tolerance is the reason

[alawrence10360]

So the 3.9 diff is in and when I took it for a brief spin I can tell the ratio is much better for the 1275cc engine. Much more relaxed , however on overun and when not in gear it is making a noise . A repetative light knock. It may be there under power but I cant hear it.
The condition was unknown when I aquired it so Im going to need to get it rebuilt I think

[alawrence10360]

Where is the best place to get a diff rebuilt or a recon unit
Many thanks

[oliver90owner]

Are you sure the noise is originating in the differential? No point in doing anything with the diff, if it is not at fault.

[alawrence10360]

There was no noise when I had the standard diff fitted
The standard will be back on tomorrow so that will be the test

[alawrence10360]

yep
seen that
thats why im going to get someone who knows what there doing
cheers

[alawrence10360]

I have put the diff flange back on the original diff and tightened the nut to 140ftlbs however the diff is now very tight.
It will turn but it does take some effort. It certainly doest spin if you put some rotation in from the flange
If I slacken the nut off it will spin but it is nowhere near tight enough and certainly not 140ftlbs
Any ideas what im doing wrong ?

[RobThomas]

Doesn't it use a one-time-only crush spacer?

[alawrence10360]

I cant see that in the manual.
If you were relacing the seal you would need to removed this nut and refit
I cant imagine you would need to relpace a crush washer every time you change a seal but I will read again

[alawrence10360]

I cant see that in the manual.
If you were relacing the seal you would need to removed this nut and refit
I cant imagine you would need to relpace a crush washer every time you change a seal but I will read again

[philthehill]

https://www.moss-europe.co.uk/spacer-co ... soc=140880

The pinion is not supposed to spin there has to be some resistance to turning - what is that resistance measured at 12" from the pinion centre?

There does need to be preload on the pinion bearings as any drive loading could push the bearings apart leading to excessive and very quick wear.

The Haynes manual (if that is what you are working from) does not mention the crush spacer directly but it does say that care must be taken when torqueing up the pinion nut.

The crush spacer is an easier option when building up the diff as it is a once only build whereas the non collapsible spacer may require the diff to be stripped several times to get the bearing preload correct.

Has your torque wrench been calibrated or checked against another torque wrench?

It is so easy to get the preload on the pinion wrong.

If care is used there is no need to change the crush spacer every time the pinion seal is replaced.

I would suggest that your original Minor diff was not fitted with a crush spacer but again care must be taken when refitting the pinion and pinion drive flange when a solid spacer is used.

[alawrence10360]

Thanks Phil
The Torque wrench is calibrated regularly
The manual is the BMC doc
At say 12inches from the centre it can be turned
I didnt check its action when i took it out so perhaps it was always tight. I was expecting to spin freely
So , are some diffs fitted with crush washers and some not on the pinion ?
This is a 67 model however you never know what is actually fitted. The ratio is right as standard