Differential Oil ?

[kent]

I need some basic info I have a 69 gt and need to change diff fluid. Haveing never done this I need to know exacty what to put in and how much. is there an easy way to fill it? also is there fliud in a man trany? or are the gears packed in grease? I know these are very basic Q's but I have limited experience and the car sat for a very long time Thanks

[baz]

hi ,if you go to
http://www.opelgt.com/sdownload/index.php?cid=1

there is a service manual you can read for all the instructions on where to remove and refill oils on the gearbox and differential

[GTJIM]

Both the diff and manual (four speed) gearbox use the same type of oil.
SAE 80 or 80-90 Multi-Purpose Gear Lubricant. Also known as EP80 or EP80/90 diff oil - the EP stands for Extreme Pressure.
The diff can be drained by removing the bottom bolt of the ten that hold the rear sheet metal cover on to the centre of the diff. If the old oil is very thick or contains silver or gold coloured metal particles then remove the whole cover and clean out the inside before replacing the oil. Replace the gasket when you put the cover back on to seal the new oil in.
The 1.9L gearbox has a filler plug - like a pipe bung, with a square head sticking out - on the side of it. The oil level should be about 1/2" below the lower edge of the hole this plug screws in to.
The diff has a similar filler plug and the oil level here should be just at the lower edge of the hole. It would be a bit hard to fill it above this level - with the plug out!