Dads dream

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?

robert miller

That is crap under warr.

sanantguy

how do you check (or they) the rear differential fluid?

sTz

Agree... should have been covered under warranty.

Dads dream

Take plug out if oil drips out level is good or if no oil stick your little finger in the hole. Level should be about 1\2 to 1\4 inch below the plug hole. If you get no oil on your finger sticking it in further level is low.

dino333

I had PDI at Museum Delivery on April 14th.On a base car. Don't know if they check this or not.

runner61627

Had exact same issue. My vette was purchased from Kerbeck and first oil change at 500 miles (z51) was serviced at Bryner Chevrolet, where the rear differential fluid was discovered to be 20 oz low. Apparently, this is a common problem with the C7 differentials. Cost me a couple of dollars as well for the fluid. Should be warranty - the advice from Bryner was to seek a recoupment from Kerbeck. Quite frankly is not worth my time and effort to pursue.
I am very happy with the service from Bryner (Steve Spencer) though - not their fault.

W88fixer

I specifically asked the dealer to check before I left with the car, they said the level was correct. Haven't checked since then (6500 miles) and no noise, maybe I will. Don

TEXHAWK0

There was a post about a GM bulletin on this a year ago...
I checked my 2014, and added the fluid myself...It was about 1/2 inch below the hole.

The non-Z51 differential capacity is 2.53 qts. I added 18 oz. to mine since it came about 1/2 inch low from the factory.

I think the differentials are shipped with fluid already in them, and no one checks them if dealer does not do it as part of PDI.

WelderGuy

Just curious... How much did the 20 ounces of fluid cost?

Dads dream

I agree .....not worth the effort. Spenc told me many owners had wrote letters to Bowling Green about this, he even had museum delivery vettes come in with low levels. At least I have peace of mind that Bryners and Spenc are doing a great job servicing my car.....however.... I am disappointed in Kerbeck not preforming a complete PDI.

Dads dream

. Total $20 bucks plus or minus a few

W88fixer

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

WelderGuy

FYI, Amazon has it for $14.27.

DAFFYDRUNK

Any opinions about how low it can be before it's hard on the diff?

WelderGuy

Probably depends on how hard you drive the car.

runner61627

You are right - I was told the differentials are shipped to Bowling Green intact with fluid; however the differential manufacturer has not been filling them correctly. Bowling Green does not check the differential fluid level, and it appears most dealers (mine was Kerbeck) are not checking as part of PDI. I did not know mine was low (20 oz) until first service at 500 miles by my local dealer (Bryner) with an outstanding Corvette mechanic (Steve Spencer), who does an extensive PDI on cars delivered at Bryner. He has also been communicating the differential fluid issue to Bowling Green. Hopefully, Bowling Green is fixing this issue.

W88fixer

Well, that's a bummer but not surprising, quite a bit of markup by the dealer. Thanks for the info though. Don

TEXHAWK0

You have to buy a quart...
When I bought mine, PN88862624, list was $26, and dealer sold it to me for $16.

MikeinAZ

This is not synthetic, when I look on Amsoils site (my preference for oil) it says it must be synthetic. I am not sure if that's the case or not but I generally run synthetic in everything and I do see a ACDelco option for synthetic lube as well on Amazon however the GM part # that is referenced matches the non synthetic oil.

I want to make sure I get the right oil in there and this non synthetic appears to be the right part # but is standard gear oil. Going to check around and see if that synthetic works as well as I prefer it to non synthetic if I have the choice. Thanks for the link, better pricing on Amazon as usual for those looking to save a couple bucks.