don't remove the drain plug till you have loosened the fill plug, that is the first tip!......

Once fill plug is released, then remove drain plug, let it all drip out then close drain plug (use a new copper washer, plug will be fine to reuse.....if it is magnetic, then clean off the metal filings from the magnet with a brake cleaner spray and a rag) and then fill through the filler till the oil drips out and stops dripping, then close filler plug and you're done....about 1.4 litres of oil (use the correct oil!)

Edit: You will want the car to be level, so up on jackstands.

 

Its worth buying one of these
Clarke CGG500 500cc Oil Suction Gun - Machine Mart
saves an awful lot of messing about when your refilling it - just take it slowly - good for refilling the gearbox as well
I use the Redline 75W90 for the diff (LSD)and 75W90NS for the box - makes for huge improvement in the change - you can use second gear from cold....
+1 what S4 says about the filler plug

 

well worth getting that gun, i used an empty washing up liquid bottle with a tube attached and squeezed it in, it worked well but for the money the gun looks easier.

 

Many thanks spiderserie4, Joe90GT and SimonGTV. Really helpful & much appreciated. Now I know where fill plug is (I'd assumed it was on top surface), the oil suction gun looks to be the thing to get. Thanks again!

 

Diff - & Gearbox - oils changed

I just thought I'd give you a quick update. I managed to change both the Diff and Gearbox oils yesterday, but it took some doing. It didn't help that it was the hottest day of the year so far, but I wanted to use it while the weather lasts!

I bought the oil suction gun from Machine Mart as recommended. I also bought a breaker bar as I knew the plugs/bolts would be stuck fast, which they indeed were!

So, after about 3 hours or so (and many bruises, grazes & sore muscles!), the oil in both compartments were changed (the gearbox was the most challenging - purely because of the poor access). I used Millers Classic Differential Oil (GL5). I know some people have recommended Redline oil, but I may try that next time...

However, whilst I was under there I noticed a gradual drip from (I think) the clutch cylinder area (under the drivers seat). I was too exhausted to investigate further so I didn't dare have the car out today (had to use an air-conditioned GT instead!). I'll have a look to see where its coming from in the week, but does anyone know what clutch/brake fluid is needed? Is it DOT5? And how much? I noticed on one of the larger Alfa Specialists the availability of a US Military-derived synthetic fluid that would never need changing, but it's nearly £40 litre and it recommends using 2 litres of it just to flush the system! Any help would be, again, much appreciated.

The attached photo is my lovely Spider. The red 156 in the background was my previous 'normal' car before I got the GT.

 

Well done, nice looker too, are your clutch fluid levels dropping?, if not check the brake fluid level.

 

Clutch and brake fluid? Castrol Super Response Dot 4. Cheap enough, good enough (even on a racetrack) and you can get it anywhere.

Avoid Dot 5 for a road car, it's designed for racers who change their fluid every two weeks instead of every two years.

 

Many thanks Jim. I'm hoping to do some investigation tomorrow night, but I've already booked the car in with my local(ish) Alfa specialist. I was planning to get the brake fluid changed anyhow this year as I've had the car 2.5 years and not had it changed in my ownership, so I've no idea how old the fluid is. It was this same reason why I changed the Diff & 'Box oil.