Differential fluid

FLIR_man · 11-21-02, 07:26 AM

My dealer told me that our C5’s are delivered with a break-in fluid in the differential that needs to be changed out after 6000 miles. I bought the car with 16000 miles on it but want to make sure if the viscosity is correct. Is there a difference in the factory installed fluid vs the “proper” fluid? The manual recommended a GM part number for a synthetic fluid. Has anyone tried any other synthetics? The dealer charges $89.00 to change out the fluid and that seems “very” high.

Thanks, FLIR_Man (Gary)

11-21-02, 10:42 AM

I used Mobil 1 synthetic gear lube with a bottle of GM limited fluid and everything seems fine 10k miles later.

MsSchroder · 11-21-02, 10:48 AM

I just called my dealer and they want $114.95 to change the rear differential fluid!

FLIR_man · 11-21-02, 11:08 AM

Both $89 and $119 sounds like a lot of money to me to drain and replace two quarts of gear oil.

FLIR-Man

MsSchroder · 11-21-02, 11:32 AM

So what's a person with no mechanical expertise to do?
wait, I bet you're going to say "learn how, or pony up the cash to the dealer"
Is changing the rear dif. fluid difficult (let's assume I can talk my mechanically inclinded husband into helping me)?

FLIR_man · 11-21-02, 11:40 AM

Read the manual last night. But I have to addmit I skimed over that section. So hear goes.
1) Jack up the car
2) Drain the fluid by removing the plug
3) Put that plug back in.
4)Remove the fill plug and add in the gear fluid and the Gm limited fluid.
5)Replace the plug.
6) Lower the car and remove the jack.

How is that for simple?

MsSchroder · 11-21-02, 11:45 AM

sounds like even I might be able to do it!

FLIR_man · 11-21-02, 11:50 AM

Yes........,

Just make sure you use safety supports. I had a car fall on me in 1970 an it was "NOT" fun spent three days in the hospital.

MsSchroder · 11-21-02, 11:58 AM

I found this link on another forum, it has a slide show showing how to change the rear dif. fluid on a c5. Does this look like what I would need to do on the Z06 if I want to change it?
oops here's the link:
http://www.picturetrail.com/gallery/...48&gid=647207&

FLIR_man · 11-21-02, 12:48 PM

Yes,

The only difference is the slide show also shows replacing the fluid in a manual transmission, just like your Z06. I do like the ramps though. Do not have to worry about the car falling.

c4c5specialist · 11-21-02, 06:19 PM

Hi there,
Please understand, look in your owners manual, and there will be part numbers listed for your axle lubricant.
In some cases, the lube is synthetic, as $25 a quart is list out for the fluid.
I recommend changes every 15k, due to the fact that the lube is NOT what breaks down, it is the friction modifier that is added to the lube.
The Getrag differential is especially sensitive to this modifier being used, and it is absolutely critical that it be used.
This will prevent slow full lock turning noises, which sound like grinding coming from the rear of the car.\
You can back your car onto the ramps, and all you need is a 10mm allen socket to change the diff fluid. DO NOT OVERFILL, OR YOU WILL GET LEAKAGE WHEN DRIVEN HARD.
I hope this helps, c4c5

MsSchroder · 11-21-02, 06:26 PM

C4C5: Can you tell me what is "Getrag differential "?
thanks for your input!
Tammy

c4c5specialist · 11-21-02, 06:33 PM

HI there,
If you wil reference the attached, this is your rear differential.
This is what is bolted to the rear of your transmission, and it is made by the Getrag Corporation.
Allthebest, c4c5

FLIR_man · 11-22-02, 06:28 AM

c4c5specialist thanks for your input.

FLIR_Man (Gary)

HallenTi · 08-10-07, 12:37 PM

Just a little addition to this fairly old post, but it holds true for most every drain/refill situation for any DIY situation.

Whether it is the rear end or transmission, it is a good idea to make sure you can get the fill plug out first. I say that because I have seen cases where someone has pulled out the drain plug, drained the fluid, then tried to remove the fill plug and weren't able to.

If they had tried to remove the fill plug first and found they couldn't, at least they wouldn't have drained out the old fluid and would have the old fluid in there then could drive it somewhere that had the proper technique to get the fill plug out. Otherwise, they'd have no fluid in there, and no way to get it back in through just the drain hole, and possibly have to tow it somewhere. Just a thought.