Topping up the diff

[tmc164]

Hi. 1968 saloon. Just went to check my diff oil for the first time and there is no filler plug where Haynes says there should be (at about 5 o'clock looking at the diff from the petrol tank). I can see the breather near the top and the drain at the bottom. A previous owner has made quite a few upgrades in other areas of the car so I guess the diff was replaced at some time. Any idea where the filler plug would be? Do sealed units exist?
Thanks

[simmitc]

Sounds like the casing is from an earlier 948 cc car. The diff might be too, so have a look at the front of the diff, on top, near where the propshaft connects. If there is a large filler plug, then there's your answer.

If a previous owner swapped the case for a 948, but kept the 1098 diff without the plug, then you could remove a halfshaft and fill from there. However, there would be no way of checking the level, so drain completely and refill with a measured quantity of oil.

[tmc164]

You are right simmitc, I can see the filler plug from the front. Thank you.