E53 4.8is rear diff plug size
 

I would like to replace the differential fluid in my 2006 4.8is. Could someone please tell me what size allen do I need to take the drain and fill plug out? I know it is supposed to be lifetime fluid, but can't hurt to replace at 60K. Thanks.

I wanted to do mine yesterday but was with the family and didn't want to mess around in 100deg weather. Hopefully I'll do it this week and let you know. When looking at it, it was huge. 19mm at least.

I tried a 17mm and it was too big. All the other sizes I have are much smaller. It seems to me that is anywhere between 14 and 16mm. Please let me know what you find. Thank You.

Which diff you doing? Front or rear? I'm going to do rear first, front when I take the skid plate off.

I want to do both. I tried to start with the rear but couldn't do it since all I had was a 17mm hex and now need to figure out what to buy. Based on my limited research around town, it appears that 14 to 16mm hex are not easy to find. Good luck with yours.

I bought a set at Home Depot for ~$25. It was like 11mm to 18mm.

Good to know. I'll be going there next. Let me know how it goes.

Figured it out. It is a 14mm hex.

Nice, sorry bro, I completely forgot to check. Been too busy with work and family. Plus my garage doesn't have AC, and it's been brutal. Good stuff though.

No worries. I am hoping it is cooler this weekend here too so I can get both done.