Hi need to upgrade my 1969, 1275cc Morris minor diff to lower the revs, what diff will fit from other cars and what ratio do I need, cheers j

that vehicle came with a ratio changer before the main transmission on a separate lever
what you say indicates that it is in low range which makes the main transmission gears all low ratio gears
a good operator can by manipulation of the 2 levers actually get 10 gears ending up with high range overdrive or 5th gear
The top speed is around the 80 mph mark (120kph)
you could have the diff fitted with a new crown wheel and pinion to a lower ratio for more speed but you will sacrifice economy and take of on hills under load capability

If you are going from a 3.8 to a 4.0 the difference will hardly be noticeable.You can make a larger difference by using a lower profile tire.(shorter lower tire)

Buy and fix 10A a car noise suppressor filter box.This will will filter and eliminate noise.

You can just change the diff crown wheel and pinion.

Hi
According to the workshop manual the adjustment is pre-set during initial assembly and there is no other provision for for adjustment.
Check page 205 of the manual at the following link.
Trust this helps, regards Alan
http://www.dolphnproductions.com/morrisminor.pdf

The size of the crown wheel gear. Ford 9 inch is a strong diff used in V8 models. The 8.8 is slightly smaller but is still a good diff. The gear ratios will probably be different. Manual gearbox cars have different ratios to automatics. The higher the ratio, the faster takeoff you will have but lower terminal speed. At high speeds , the high ratio differential will cause high engine revs and poor fuel consumption. A low ratio will be mediocre takeoff but allows high top speeds and lower engine revs. (Good for fuel economy if you are mostly highway driving)

remove the battery lead. remove the drive shaft at the diff flange and remove it from the gear box. undo engine mounts/ cross member at rear of gear box if necessary. undo bell housing bolts around rear of engine. remove gear lever if stick shift . If not remove linkages at gear box Pull gearbox rear wards and lower to the ground . A point of interest here is that when a clutch sudders it is advisable to firstly check all the engine mounts are not soft as this affects the clutch operation especially if you have a cable operated clutch

If you cannot do a side by side comparisson I would Google the specs and see what is different. it may just be slightly diff gearing or a minor mod..it might be a totally different box.
cheers
Roger

Hi The distributer should have an offset drive so it can only go back in the same way it came out,
As to no spark:
Check the contact points
Condenser
Tiny earth wire from breaker plate to distributer body.
Coil
Ignition supply and ballast resister.

Morris cars originally had a positive earth system on the battery if you change to negative earth you must check the coil connection the Neg - terminal on the coil goes to the distributer and the Pos+
is ignition supply

contact a morris club for a good idea as to the value. Remember the car will only have value if restored to as new condition using genuine parts. I would start at around $30.000.00 aud