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In previous threads people have posted the plug is a square 3/8 drive plug.
I just crawled under my 2017 and while the drain plug is a 3/8 drive the fill plug appears to be a t40 torx plug. It is also in really tight. Has anyone else experienced this with a 2017?
I didn't remove it since I don't have any fluid to refill with but it sure looks like a real PITA to get out.
You may be looking at the ediff clutch pack drain or fill. You don't want to mess with that.
Exactly! Or you will be looking at a dealer visit since it requires a special tool to bleed the ediff hydraulic system. Here is a link to the information in the tech forum for both rear differential and ediff maintenance: https://www.corvetteforum.com/forums...ice-specs.html
The plug is located above the drain plug on the passenger side, adjacent to the part of the tailpipe that goes over the passenger side half shaft. It and the drain plug at the bottom of the casting are the only plugs visible while laying under the car.
The fill plug is screwed into a circular cast boss that protrudes from the case. The plug is definitely a t 40 torx. A 3/8 or a 1/4 drive do not fit in the plug bore.
The car was manufactured in early December 2016. Possibly there was running change in production.
T40s suck next to a 3/8 square. as it twists and strips vs the 3/8 just plug in and spin off! It certainly is not space limited like the C6Z brake pad torx bolts.
The dif drain/fill plugs on my Forester required an impact gun to get them open from OEM, glad they were 3/8 or 1/2" square.
Today I was looking for the transmission drain plug and it turns out it is what I thought the differential drain plug was. I found the differential drain and fill plugs on the opposite side of the jacking point cross member towards the sway bar.
Good thing I never took out the torx 40 plug which is apparently for something else, maybe the e diff fluid as a previous poster postulated.
Anyway the fill plug is indeed a 3/8 square recess plug and indeed it is a major PITA to get out and even worse to get tightened.
As with most things on cars there is a easy way to do it once you have spent some time doing it all the hard ways. I do have a flex socket wrench but after many, many years of use it the flex assembly is really loose so getting it into the fill plug was a major adventure. Time for a replacement piece.
2020 Corvette of the Year Finalist (performance mods)
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Originally Posted by lgodom
You can get an inexpensive flex head 3/8 from Amazon. I bought one, but haven't used it yet. It looks to be made well enough for infrequent use.
The flex head/articulating 3/8 will be your friend. The fill plug is in a tight spot. Surgical/rubber gloves also help when putting it back in. Gives you a better grip so you don't drop it.
Finally got around to this today in my '15 Z51 A8. This was at 9,500 miles of street driving, no track time.
A flex head ratchet is a MUST. I used a 3" extension for the fill plug and a 10" extension for the drain plug.
Not sure if there is a difference between the A8/M7, but there are some heat exchanger lines with little radial fins by the drain plug that are a PITA to work around. No way to remove the plug without denting the fins slightly.
Overall it took me about 1.5 hours, mostly because I was pondering how to deal with the cooling lines. Eventually I just said F-it, and went after it. Turned out fine. Doing over could do in an hour or less.
Fill Plug access:
Drain plug access:
Here you can see how the extension dents the radial fins:
And the mess it makes... I used brake cleaner to clean up afterwards. And I'd remove the plastic air deflector next time...
Fill Plug:
Drain Plug:
Drain Plug:
This is the Plews pump from amazon and the GM LS oil. The pump got 99% of the oil from the bottles. I was impressed!
04-26-2017, 07:20 PM
2017 differential filler plug
The flex head/articulating 3/8 will be your friend. The fill plug is in a tight spot. Surgical/rubber gloves also help when putting it back in. Gives you a better grip so you don't drop it.
