decided last minute to change the rear diff fluid...

[Roadster Guy]

Dropped the Vette at the GM dealer for an oil change before winter storage. At the last minute I asked them to change the rear differential fluid. My idea. No problems or no noises back there. I have always changed all fluids on a regular basis (oil, tranny, coolant, brake) but never the real diff. And I suddenly thought, why not do it?

My Vette has 43,000 miles, never winter driven and is now approaching 14 years old and I believe the fluid is original. Now, the manual says it is lifetime fluid, but I know the commonly held view is it should get changed. I don't race or track the car. As I put on about 3500 miles per year, I guess I am good now for a while. The dealer said it should be changed every 30,000 miles. Sounds a little frequent to me for normal street driving, but I'm really not sure.I have talked to people who never change it.

How often do you change the rear differential fluid? Does it depend on the way the car is driven or time or both? Or have you never changed it and have tons of trouble free miles?
RG

 

[toptechx6]

Now you've done it! That CE is no longer "original".

 

[TWISTERUP]

I changed mine at around 70 K shortly after I purchased the car. I did the tranny-coolant- power steering and brakes, for my own peace of mind. As you say I wouldn't think you would need to change as often on a car that's not being tracked/raced on a regular basis. I work at a dealer and sometimes their recommendations seem a little too often IMO. Being a GM dealer I'm sure they didn't forget the "limited slip" additive.

 

[Roadster Guy]

Now you've done it! That CE is no longer "original".

But I saved the old fluid in a jar in case the next owner wants it!

 

[Roadster Guy]

I changed mine at around 70 K shortly after I purchased the car. I did the tranny-coolant- power steering and brakes, for my own peace of mind. As you say I wouldn't think you would need to change as often on a car that's not being tracked/raced on a regular basis. I work at a dealer and sometimes their recommendations seem a little too often IMO. Being a GM dealer I'm sure they didn't forget the "limited slip" additive.

The limited slip additive was on the bill. I had discussed it with them when I decided to do it. It's a good dealership and I've always been happy with them, though I've only had fluids and minor service done, nothing major. They are recommended and used by the local Corvette club which says something.
RG

 

[92BlackVette]

I replaced my OEM fluid at 100,000 miles and waiting so long caused my clutches in the limited slip unit to go out.