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Well, prompted by this thread, I checked the oil level in my base 2014 C7. Despite being told by the selling dealer that the oil level was OK, it was not. Went to my local dealer, Corvette tech looked at the GM website which said the level should be no lower than 1/4" below the fill plug and for those who haven't gone there, a 1/4" drive extension works perfectly and the torque spec is 20 ft lbs.
A qt of the GM Dexron LS Gear lube ran me almost $28 counting tax. Will see if I can finess it and drain just enough so that I can empty the qt and bring it up to the full level.
Doubt that the level is low enough to have caused an issue, I am gentle with the car and my finger did feel the oil but well more than 1/4" down. Glad I checked.
First service writer was clueless but another took charge and got it done.
Stopped at an O'Reilly and ran into two morons. One said a siphon was a fill pump and that the container you're using to fill from didn't need to be above the item you're filling. Another thought that test strips to see if your antifreeze was alkaline or acidic was a hygrometer. Geeze Don
I dont understand ,,you have to drain it to add more ??
Took my 2015 coupe for oil change and service tech found the rear differential 20 ounces low. He said most c7's he services have low rear differential issues from Bowling Green. So much for dealer PDI! Also had to pay for the 20 ounces of lube oil. Anyone else finding this issue?
Received a notice to have my September 2013 built Z51 differential fluid checked in October 2013. The Corvette certified mechanic told me mine was fine.
Well, prompted by this thread, I checked the oil level in my base 2014 C7. Despite being told by the selling dealer that the oil level was OK, it was not. Went to my local dealer, Corvette tech looked at the GM website which said the level should be no lower than 1/4" below the fill plug and for those who haven't gone there, a 1/4" drive extension works perfectly and the torque spec is 20 ft lbs.
A qt of the GM Dexron LS Gear lube ran me almost $28 counting tax. Will see if I can finess it and drain just enough so that I can empty the qt and bring it up to the full level.
Doubt that the level is low enough to have caused an issue, I am gentle with the car and my finger did feel the oil but well more than 1/4" down. Glad I checked.
First service writer was clueless but another took charge and got it done.
Stopped at an O'Reilly and ran into two morons. One said a siphon was a fill pump and that the container you're using to fill from didn't need to be above the item you're filling. Another thought that test strips to see if your antifreeze was alkaline or acidic was a hygrometer. Geeze Don
That oil is thin, and comes out very quickly...Don't think you are going to be able to let oil out without it spraying everywhere....
If I were going to go to the trouble to pull the plug, I would just go ahead and drain it and change the fluid...
By the way, I rigged up a way to use my small air compressor, some plastic tubing, and couple of holes in the cap of a fluid bottle to push fluid up and into the differential at a controlled flow....
The air puts pressure on top of the fluid in the bottle and forces it down and out the fill tube that goes to the bottom of the bottle.
Forgot to mention, set the air pressure low so you do not overpressure the bottle.. You will see it bulge a little as you release air to it.
I dont understand ,,you have to drain it to add more ??
No, I seriously doubt that it will take anything near a qt to bring it up to full as a qt is about 40% of the total differential capacity.
If I can finagle it, I will use a crude dipstick to see how far down the oil level is and drain just a bit out and then fill to the full level with what is left from the fresh qt if that makes sense to you.
That oil is thin, and comes out very quickly...Don't think you are going to be able to let oil out without it spraying everywhere....
If I were going to go to the trouble to pull the plug, I would just go ahead and drain it and change the fluid...
By the way, I rigged up a way to use my small air compressor, some plastic tubing, and couple of holes in the cap of a fluid bottle to push fluid up and into the differential at a controlled flow....
The air puts pressure on top of the fluid in the bottle and forces it down and out the fill tube that goes to the bottom of the bottle.
Forgot to mention, set the air pressure low so you do not overpressure the bottle.. You will see it bulge a little as you release air to it.
You can purchase a small hand pump at Harbor Freight for a few dollars. The pump screwes unto the oil container and a hand crank supplies the motive force.
You can purchase a small hand pump at Harbor Freight for a few dollars. The pump screwes unto the oil container and a hand crank supplies the motive force.
I know. I had one of those, and the plastic plunger broke off before I even got the fill tube full of liquid....
That is why I had to come up with an alternate solution....
I was sitting in the garage, with the fluid drained out of the differential, and no easy way to refill it.
Plus, it is a lot easier to just squeeze the air nozzle and let the air pressure do the work than to try to pump the fluid back in with the little plastic pump...
In addition, the plastic pump actually draws the fluid out, so you get leaks when you are trying to pump the fluid, whereas, the air method uses air to push the fluid out, so if the bottle or tube leaks, it is only leaking air, not fluid.
I don't know why it's so hard to find a decent fluid transfer pump. I had a Penzoil pump, an absurd collection of cheesy tubes and fittings, worthless. I have a new one that looks much more substantial but want to keep it for gas transfer between cars, law tractor and portable generator etc and not foul it with messy diff fluid etc. Don
You can purchase a small hand pump at Harbor Freight for a few dollars. The pump screwes unto the oil container and a hand crank supplies the motive force.
so I understand ..you want to take out all the fluid...and then add the appropriate amount that GM calls for ....so you know you have the correct level ..
some pictures of where these plugs are would be nice.
Thanks for the nice bit of paranoia about something
that should be a no brainer and filled properly on a new car. There is no excuse at all for any car
to be low on this, or any other fluid, brand new.
SB #13384 covers 2014 models that expired on Nov. 30, 2014, so you'd think 2015s would be relieved of these checks.
Originally Posted by sanantguy
some pictures of where these plugs are would be nice.
Here's a diagram from the 2015 owners manual (p. 10-34) showing the filler plug. The arrow is my edit. It points to a plug not shown in the pic that's lower than the filler plug on the left side. I assume that's the drain plug.
Questions for the community: Should the plug be re-installed with Loctite 272 (red)? I saw that mentioned in another thread but the owners manual mentions nothing, not even a torque value. If red Loctite is used originally it should need some heat to remove. Does it matter if the axle is warm or cold for the fluid check?
SB #13384 covers 2014 models that expired on Nov. 30, 2014, so you'd think 2015s would be relieved of these checks.
Here's a diagram from the 2015 owners manual (p. 10-34) showing the filler plug. The arrow is my edit. It points to a plug not shown in the pic that's lower than the filler plug on the left side. I assume that's the drain plug.
Questions for the community: Should the plug be re-installed with Loctite 272 (red)? I saw that mentioned in another thread but the owners manual mentions nothing, not even a torque value. If red Loctite is used originally it should need some heat to remove. Does it matter if the axle is warm or cold for the fluid check?
No Loctite required on plugs..They have gaskets so do not have to be overly tight..torque spec. is 20 ft-lbs.
Drain and fill plugs are not too hard to find...
Also, instead of using one of those cheap plastic bottle pumps, I rigged up my air compressor to use air pressure to push the fluid into the differential...
Just drilled a hole in the cap for the filler tube to insert into the bottle (all the way to the bottom) and a hole for a small tube to supply the air pressure. Air is on top of the fluid, and pushes the fluid down and out the fill tube.
Also, instead of using one of those cheap plastic bottle pumps, I rigged up my air compressor to use air pressure to push the fluid into the differential...
Just drilled a hole in the cap for the filler tube to insert into the bottle (all the way to the bottom) and a hole for a small tube to supply the air pressure. Air is on top of the fluid, and pushes the fluid down and out the fill tube.
Why couldn't you just use the one larger tube and apply pressure by squeezing the plastic bottle? I found this "Flotool" at Pepboys.com.
I checked mine today and it was around 1/2" below the hole when cold at 93°F ambient, which BTW is the minimum specified in the 2015 owners manual (p. 10-34), not 1/4" as previously stated in this thread. I may fill mine all the way up anyway. My car is non-Z51 with a 12/18/2014 build date.
Why couldn't you just use the one larger tube and apply pressure by squeezing the plastic bottle? I found this "Flotool" at Pepboys.com.
.
You can, but you will never get all the fluid out of the bottle unless you can get the bottle above the fill hole...
It is just easier to squeeze the air nozzle on the compressor hose and let the air do the work... Also, you can watch the level in the bottle and easily control how much and how fast the fluid goes in...
It also seems like with pumps and squeezing the bottle there are always leaks... By letting the air push the fluid out, if there are leaks it is only air since the fluid is forced down and out the tube from the bottom of the bottle...
Just an engineers solution to a problem..
but it was born out of necessity, I had a plastic pump, it broke on the second pump, so I was in my garage with the fluid out of the differential, and no easy way to get the fresh fluid back in.... I came up with this alternate method.
Once you have the cap made, it makes all other methods I have tried obsolete.
You can, but you will never get all the fluid out of the bottle unless you can get the bottle above the fill hole...
I haven't actually tried it, but there seem to be one or two places that would qualify--like just rearward of the right rear shock, assuming the tube is long enough to reach. As for leakage, you would think the Flotools item previously linked might not if it's a decent product.
OTOH, once constructed your method would be easier. I think it's also better if you plan on changing the fluid yourself in the future. With a 72k-mile maintenance schedule I probably won't and may not do this procedure again, as I just want to add some fluid, likely less than a pint. OTOH making the cap/tube assembly you describe can be done easily with my existing inventory of stuff lying around the garage.
It does not fall under warrantee because who ever does the PDI is supposed to check and top off all fluids. So if the same dealer who serviced the car new is doing the oil change should not charge you for the added fluid they found low during a oil change. If the dealer sees a leak, the leak is repaired under warrantee and the added fluid is part of the warrantee claim.
Took my 2015 coupe for oil change and service tech found the rear differential 20 ounces low. He said most c7's he services have low rear differential issues from Bowling Green. So much for dealer PDI! Also had to pay for the 20 ounces of lube oil. Anyone else finding this issue?
I asked the dealer I bought my car from to check the fluids before I drove home from KC to Seattle and when I arrived I asked the internet sales manager had that been done and he said yes !!! So I drove my car home 3200 miles and when I arrived home I took it to my nearby dealer ( also our Corvette Club sponsor ) and when they checked the fluids they found no signs of abnormal low readings . Wayne
Last edited by wgood; 09-01-2015 at 11:36 PM.
Reason: Mine is a Z-51
I asked the dealer I bought my car from to check the fluids before I drove home from KC to Seattle and when I arrived I asked the internet sales manager had that been done and he said yes !!! So I drove my car home 3200 miles and when I arrived home I took it to my nearby dealer ( also our Corvette Club sponsor ) and when they checked the fluids they found no signs of abnormal low readings . Wayne
Who is your dealer/club sponsor? What club are you a member of down there?
08-29-2015, 12:39 PM
Thanks for the heads up as I will have my dealer that does service check on my next oil change.