Hi all
I just traded my old SS Camaro for a Red 98 C5 with Auto Trans
I have not owned a Vette since 1966 and it was a 63 340 hp 4 speed.
I drove the C5 home on Sat from Omaha, than went for a ride today and
noticed a growling, grinding, or rumbling sound from the rear end.
It is the same in N or in gear, coasting or in D in a straight line with
no change when turing, The owner said the diff fulid was changed with
Mobil 1.
Any ideas?

 

I'd call the previous owner and ask him/her where the car was serviced. If you do get this info, call to ask if there were any rear end issues with the car. How many miles are on the car?

 

It has 105,000 miles and I did talk to the orignal owner and the rear end
was changed with Mobil 1 75-90 at 96,000 they said it always had a little
growl in the rear. I took it to a shop and the tech looked at the tires and
showed me just the inside rib on the tread on all four was rough. He said
to have them moved side to side and see if the sound went away.

 

Automatic!???

 

The diff does get 75-90 weight but I found this tidbit of info:

However, if the sound you hear is constant and not just when rounding corners, it could be the tires or a wheel bearing.

 

I had the tires moved L to R but one rear was very chopped, but the tire shop had
a set of Goodyear run flats with 5,000 miles that the customer said were to rough
riding. I bought both for $100. and now the rumbling is gone but I need to take it
back for alignment after I replace the right out side tie rod end.
Thanks