Z06PA

So I've been reading on here about rear diff being low on fluid. Car has 300 miles, I decided to check it and yup almost full quart low with car level.

Car was built 02/2016.

Higgs Boson

take it in, they fix it for free

juanvaldez

According to the folks at Spring Mountain, a differential fluid change early on is a good idea.

BELVIN20

Don't feel bad, my 2016 Z, built same month as yours was a quart low as well. GM has had many problems with diff not filled correctly, there are many post on the forum about the problem.

Hrlyrdr22

Glad I ran across this thread. 40 miles away from 500 mile oil change. I'll make sure I have the diff fluid checked as well? I assume this is a known problem and they will do it at no charge? Thanks

Z06PA

Well, I had it up in the air and a quart of the fluid on hand so I just filled it until it started to overflow. Easier at this point than going to dealer...

Z06PA

I would check it for sure this sort of thing will only lead to headaches later on and most likely when out of warranty.

A better idea would be to just have them dump the fluid and refill. They will most likely charge for that but it's money well invested to get all the brake-in metal out of there...

23/C8Z

Mine was maybe pint low.

M​​​​​​y buddies? Full quart. Checked right after mine maybe 200 miles on his. I had around 400.

unreal.

this forum was why I checked glad I saw it (earlier thread was about a month ago when we had them in air).

2fastnow

My 05 GTO back then was down a 1/2 quart brand new. Found from info back then forums.
Royal purple got rid of a whine it had at 50 mph.
It was in the news that the same assembly worker was transferred to Kentucky where he shorted many diff's till he was arrested!

capevettes

I recall when I changed the fluid in the rear diff of my last C6 Z, I would fill it until it began to weep out of the fill hole. Then you needed to drive it a short distance or rotate the rear wheels and then top off the fluid. It needed quite a bit more after the fluid circulated. I know the new diffs are filled by the suppliers and then installed in BG. I wonder if this accounts for all the pumpkins low on fluid.

5thGear

If it is they will fluid at no charge.
My recommendation is that while they are doing the 500 miles oil change to also drain and refill the differential. There is no extra labor since the car is already on the rack and this can be done in parallel with oil change. You just pay for fluid which is around $100. The differential does get very hot during break in. It's a good investment to clear the differential from break in fluid and any possible tiny metal shavings (if any). It's very important to replace the fluid after the first track day as recommended in the manual.

8850

Better check mine. I just had my 500 mile oil change then read this.

Will Royal Purple be a problem? Have two new quarts. Will two fill it? Maybe just top it off?

5thGear

This is an electronic rear differential and uses very specific fluid and it's not cheap. I would only use OEM fluid.

8850

Good point! Thanks!

davepl

$22 on Amazon was about right:

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

vntgmbk

Knowing that this is a common issue shouldn't the dealers check this prior to delivery to the customer? I am sure many of the larger dealers have heard about this by now.

8850

Or better yet why doesn't GM check fluid levels before they even leave Bowling Green. This is a problem us owners should not have to be dealing with.

OnPoint

This. The fact customers are still having to deal with improperly filled rear diffs and A8 trannies with problems at this stage of the model run is simply inexcusable.

jcthorne

How many quarts for a fluid change?

Z06PA

I would use OEM fluid but it hasn't changed in years. It was the same fluid used on the C6s