cb98coupe

I just got my car back from my dealer for an infotainment issue . While the car was there I asked my service advisor to check the rear diff. fluid. I don't know why but I just crawled underneath the car and it is very low !!!!! I stuck my finger in the hole and I could not feel a thing . I am going to be the first person on line this morning . I don't even know if I can sleep . Pissed is not even the term right now .....

arcticblast

Breath deep.
Seriously, it's easier to deal with the dealer when you're calm (for both of you). Good luck getting this taken care of.

cb98coupe

I'm cool and I am sure there is enough fluid to get by because I have 4300 miles and no problems . It just pisses me off that they can't do a little thing like that when i asked them to check it ......

Zymurgy

Does the service sheet you got after the service state that they checked the diff level? When the service advisor wrote up your service did he list the rear diff check? Did you verify he had it listed?

cb98coupe

Good question zymurgy and I just checked the sheet , not listed on the sheet . The service drive was packed and my S.A just grabbed my keys and got me going because it was the second time in for the infotainment issue . I called him and specifically told him to check . I guess I can blame myself somewhat . I have a very good relationship with my S.A. and he is a good guy but I should have checked my papers before I left . I am going in this morning and I am sure they will just add some and I will be on my way . It's nice to be able to come here and let it out a little bit .....

Zymurgy

He probably had every intention of adding the diff check to your service order but got sidetracked by another customer (call, visit) and it slipped his mind. Glad to hear you have a good relationship with your S.A. This should not change that.

cb98coupe

It won't , I really like the guy and he always goes the extra mile for me . I just got really worried when I felt around in the hole and it was really low . I now sit here and realize that there is enough fluid in there for the time being and they will just add some this morning . Life will go on . I get a little excited sometimes and I never lose my cool at the dealership .....

howellvette

Take a gallon of Gentleman Jack to him and split it between the two of you and do burnouts in the parking lot down by the Sparks LOL Yall be cool

cb98coupe

Probably a good idea . I wonder how many people are driving around right now that have no clue about the level of their diff. fluid . I also wonder if down the line we will start to see failures of said component .....

TEXHAWK0

Weren't the low differential levels just on a few Z51 cars, or is it more widespread than that?

cb98coupe

Ok , update , I went to the dealer and they took it right in . Apparantly the fluid is not supposed to be right up to the weep hole . The Tech and the service manager assured me that my fluid was full . The tech stuck his finger in and showed me the fluid . They told me that if it is filled up too high it will start blowing out the sides . So , I would be careful if you are checking yourself .....

cb98coupe

Others have stated that the fluid in some non-Z51 cars were low . I say , better safe than sorry . I checked mine just for good measure and I am glad I did , even though the level was fine .....

W88fixer

The owner’s manual says the diff fluid should be to the bottom of the fill hole. That’s what has been the case in the past in most cars if I’m not mistaken. Don

cb98coupe

I must have understood it differently . I thought you should be able to stick your finger in and feel it immediately . Apparently you have to stick it in a little ways .....

TEXHAWK0

I just found another post where a non-Z51 differential was low that was built in June.

I checked mine and it was about 1/2" below the fill hole.
It took about 18 oz. to bring it up to the bottom of the hole.
Maybe GM is trying to keep the level a little low so they will not have problems with the half shaft seals leaking, like they did on the C5s.

Also, an easy way to check just how far below the hole the level is, is to take a twist tie (like you use on trash bags) bend about 1/2" at a 90 degree angle. Inset it in the hole and lower the long part until it rests on the bottom of the hole. Carefully pull it out without touching the sides of the hole, and you can read the level on the short part.
That way, if you cannot touch it with your finger, at least you will know exactly how low it is.

SRQStingray

No, non-Z51s had a TSB. My differential fluid was down 1.25 quarts at 4300 miles. There is a TSB on it, but my selling dealership did NOTHING. My buddy and I discovered it was low and filled it. A forum dealership then drained the oil, checked for signs of excessive wear and refilled it.

The TSB is:

Bulletin No.: 13384
Date: November 2013

Google it to fine the full bulletin.

TEXHAWK0

Since you are going back, I would ask the dealer to note how much they have to add.
Mine was about 1/2" below the hole, and I had to add around 18 oz. to get it up to the bottom of the fill hole.
When I last changed the diff. fluid on my C5 Z06, it only held 1.8 qts., so being2/3 qt. low cannot be good for it.

thedofuss

a little knowledge is a dangerous thing...or words to that effect.

Vetteman Jack

Good that the diff fluid level was OK. Never hurts to ask though - the peace of mind is priceless.

cb98coupe

I appreciate all the feedback my post has provided . Hopefully this will help others out there . I feel better now after going to the dealer . The tech was able to put his finger in and get a reading and said the level was good . The dealership I go to has some pretty nice people there and they even took me in the back to show me that the level was ok , at least that's what they said and that's good enough for me . I still think that everyone should check theirs as the rear diff. has very easy access .....