Definitive Answer Needed: 2009+ Differential Drain Plug
Thread Starter
Instructor
Joined: Sep 2005
Posts: 136
Likes: 18
Definitive Answer Needed: 2009+ Differential Drain Plug
Went to drain the diff fluid in my 2009 base coupe / manual trans / non-Z51 car. The main drain plug is a fraction of an inch above the spring. Similar in concept from what I have read about the 2005's, but MUCH closer to the spring. A cut down l shaped allen wrench will not fit in there and I am not sure there is even enough space for any tool and the plug itself - super close.
Here are some threads I found:
https://www.corvetteforum.com/forums...ange-help.html
https://www.corvetteforum.com/forums...mpossible.html
The second thread suggests that the horizontal plug directly above the vertical plug should be used, but not much supporting evidence there. I'm not sure that location would drain as well and not sure which one has a magnet on it.
Anyone have a "real" GM service manual that defines what should be done?
Anyone with first hand experience with one of these later cars?
Thanks!
Here are some threads I found:
https://www.corvetteforum.com/forums...ange-help.html
https://www.corvetteforum.com/forums...mpossible.html
The second thread suggests that the horizontal plug directly above the vertical plug should be used, but not much supporting evidence there. I'm not sure that location would drain as well and not sure which one has a magnet on it.
Anyone have a "real" GM service manual that defines what should be done?
Anyone with first hand experience with one of these later cars?
Thanks!
Le Mans Master
Joined: May 2016
Posts: 7,055
Likes: 1,546
From: Florida
Went to drain the diff fluid in my 2009 base coupe / manual trans / non-Z51 car. The main drain plug is a fraction of an inch above the spring. Similar in concept from what I have read about the 2005's, but MUCH closer to the spring. A cut down l shaped allen wrench will not fit in there and I am not sure there is even enough space for any tool and the plug itself - super close.
Here are some threads I found:
https://www.corvetteforum.com/forums...ange-help.html
https://www.corvetteforum.com/forums...mpossible.html
The second thread suggests that the horizontal plug directly above the vertical plug should be used, but not much supporting evidence there. I'm not sure that location would drain as well and not sure which one has a magnet on it.
Anyone have a "real" GM service manual that defines what should be done?
Anyone with first hand experience with one of these later cars?
Thanks!
Here are some threads I found:
https://www.corvetteforum.com/forums...ange-help.html
https://www.corvetteforum.com/forums...mpossible.html
The second thread suggests that the horizontal plug directly above the vertical plug should be used, but not much supporting evidence there. I'm not sure that location would drain as well and not sure which one has a magnet on it.
Anyone have a "real" GM service manual that defines what should be done?
Anyone with first hand experience with one of these later cars?
Thanks!
Le Mans Master
Joined: May 2016
Posts: 7,055
Likes: 1,546
From: Florida
OK, these two pics should show you, hopefully they're rightside up.
You need a 10mm allen key wrench and a 10mm, box wrench. Cut a 13/16" (.812") piece off the allen key. It doesn't need to be accurate. I used an abrasive cutoff wheel. Round off all six corners on both ends.
In the pic the the allen cut piece is in the jaws of the calipers. In the second pic, insert the allen cutoff piece into the plug, there is plenty of room to use the 10mm wrench to remove the plug.
Pics came out sideways. Wish I could get my iphone to act right!!
You need a 10mm allen key wrench and a 10mm, box wrench. Cut a 13/16" (.812") piece off the allen key. It doesn't need to be accurate. I used an abrasive cutoff wheel. Round off all six corners on both ends.
In the pic the the allen cut piece is in the jaws of the calipers. In the second pic, insert the allen cutoff piece into the plug, there is plenty of room to use the 10mm wrench to remove the plug.
Pics came out sideways. Wish I could get my iphone to act right!!
Last edited by BlindSpot; Oct 11, 2017 at 07:15 AM.
Limping across the line
Joined: Oct 2002
Posts: 5,299
Likes: 109
From: Peoria Az
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Thread Starter
Instructor
Joined: Sep 2005
Posts: 136
Likes: 18
HOWEVER - my spring is so close to there is no room for this either. I have a two post life so the tires are hanging. I then lowered the car onto some blocks which gave a fraction of additional space. The plug had less than 1/8" clearance to slide out.
Bottom line for others: This will work, but not when the car is in the air. I would also suggest driving onto a ramp as lowering onto the blocks the suspesion did not fully settle.
What where they thinking when they designed it this way?
Race Director
Joined: Sep 2000
Posts: 11,139
Likes: 1,910
From: Missouri City, TX
Wow!! I thought this problem was solved starting with MY2006. The diff drain plugs on the 2007 and 2008 F55 cars are exposed and not over the top of the composite spring as I have done fluid changes on both.