[ColTheWol]

Hi, I am purchasing the tools I will need to change the oil in the transfer case on my 320d F30 2015.

Do I need to buy a replacement plug\screw or could I reuse the existing one?

[dholdi2]

There is only the fill plug, no drain plug.
I reused the existing one.

[Allworth]

+1 for reuse. Bolt is similar to one for an engine oil sump, which has no recommendation for a change after every use.

[ColTheWol]

Originally Posted by dholdi2

There is only the fill plug, no drain plug.
I reused the existing one.

Great, thanks, you saved me a few pounts

[ColTheWol]

What about the oil seal?

[Mkesler75]

Just my two cents but for the $3-4 cost I’d have one on hand. As history has shown you never know what can go wrong. If something happens you are a few days from getting that new plug.

[Allworth]

Originally Posted by Mkesler75

Just my two cents but for the $3-4 cost I’d have one on hand. As history has shown you never know what can go wrong. If something happens you are a few days from getting that new plug.

Just because you can afford a new bolt doesn't mean you need it. 'You never know' is this an argument to buy a bolt?

Personally never had issues with a drain bolts, I once had thread destroyed on my old e34 by some mechanic, and it was sump's thread, not a bolt's thread.

[Mkesler75]

Originally Posted by Allworth

Just because you can afford a new bolt doesn't mean you need it. 'You never know' is this an argument to buy a bolt?

Personally never had issues with a drain bolts, I once had thread destroyed on my old e34 by some mechanic, and it was sump's thread, not a bolt's thread.

We are not talking a costly part here. I’m extremely budget minded. My point still stands. These are not easy to find. It would be a shame to have down time over a very minor part. Again, I’d side with caution and have an extra on hand. You never know who you may help down the road. It’s just my opinion, take it or leave it. My experience over the last few years doing just about every PM service on my car is that it never goes as planned. Be prepared.

[dholdi2]

Its a steel bolt in an ally case so if you have thread issues then your in a whole world of pain.
I suppose you could drop it and it rolls off into a drain.

[TurboWeasel]

If it's anything like the rear diff plug with the integrated green viton O ring, I'd stick a new one on personally. If it's a crush washer, they're OK to reuse given how infrequently they come off, but rubber O rings shrink and degrade over time.

[Allworth]

Originally Posted by TurboWeasel

If it's anything like the rear diff plug with the integrated green viton O ring, I'd stick a new one on personally. If it's a crush washer, they're OK to reuse given how infrequently they come off, but rubber O rings shrink and degrade over time.

Diff I have done had no rubber o-ring, it should be replaced if there is one.
I am aware they often come in a set with a bolt, speaking of integration I once did EGR clean and a rubber o-ring has fused to aluminium and turned to stone, had to scrape that off.