Transmission and differential oil change

Hi everyone, My C4S 2002 equipped with a 6 speeds MT is now ready for a transmission and differential oil change. That's something I want to do by myself and Im trying to gather all parts needed before beginning the work. I already choose the oil which will be the Porsche fluid 000-043-305-49 75w90 grade oil that everyone seems to appreaciate. My car is not equipped with an LSD and dont see track except for PCA events once in awhile so it seems the way to go. Dealer was asking 55$ Cdn per lts but figured out they could sell me bulk oil they buy in drums for 42$ lts instead. My question is about the drain plugs for the transmission/rear diff and the front differential. I want to have spares in case I damage the original ones... For the front diff here's what I found: N 016 161 1 Screw plug M18x1.5 (Fill plug) 900 124 025 02 Screw plug M18x1.5PM (Drain plug ) It seems that there is no sealing ring on theses drain plug can someone confirm this? For the transmission and rear diff: 900 219 001 02 Screw plug M22x1.5 900 123 118 30 Sealing ring This seems to be the oil fill plug only and cant find any P/N for the drain plug. Are they both the same? On the technical drawing I can see the quantity required is only 1 for theses P/N. Please see attached drawing: See Items 1 and 9 Any help would be really appreaciated Thanks Hugo

There is a drain plug, same size but with a magnet. It also has a copper Oring. I don't know why the diagram did not show it on there.

I did this recently on my C4. I found no sealing rings on the front plugs. They have a tapered feature, so I have to assume that is intended to keep a seal.

Thanks Scott! Im now ordering the parts. I also figured out the transmission needs: 2x 900 219 001 02 screw plug M22x1.5 2� 900 123 118 30 sealing ring both fill amd drain plugs are the same but the PN has been supersed by 900 219 001 30.. They call this plug everything but transmission drain plug ask me why..

Be warned if it�s the first time that those drain plugs are in there tight. I�m sure it�s pretty trivial on a lift but under the car on jack stands I could not get any good angle with my 1/2� breaker bar. When I felt that start to bend, I decided to pass on the job and let my Indy handle it. Only a hundred bucks or so vs. a nightmare with me likely stripping out the plug if I�d continued.

Thanks for letting me know. Yes its the first time, the transmission have been rebuilt by the previous owner 4 years ago but I dont know what to expect. I dont have any records for the front diff. Do you think I can spray some lose nut a couple times and heat the casing after a good run can prevent the problem?

I only have the one data point, unfortunately. Lots of folks have done no problem though, so I don�t want to scare you off. I just decided since the cost was low and it�s not time critical to let the pro with the right setup handle it.

A couple of basics: 1) Make sure you have the right tool and good access/ leverage. 2) Always remove the fill plug first. If you can't get it out, after removing the drain plug - you're going to have a bad day.

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I've never had too much trouble doing this but that's no guarantee . As above, be sure you do number two first.

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I had a tough time getting the fill plug out. There was not enough clearance on jack stands to use may breaker bar. I ended up using 3/4" conduit to extend the handle of my wrench.