I am kind of ignorant in this area. Until I started reading the forum, didn't even thing about it. This is my first car with lots of ponies, OH what fun.
Seem to be getting the whin, mainly between 40 and 50 mph under very slight acceleration. Hit the gas - sound gone, let off gas sound gone. Almost sounds like the whin I used to get from snow tires in the old days.
One of the advantages of growing older is that your car automatically runs quieter, just don't hear as good any more.
If you are pressing just enough to maintain the speed, then yes. I'm no expert, but from experience thats what happened to me. Sorry
09-23-05, 05:21 PM
I have a similar whine that occurs right around the 1800-2000 RPM range, especially in sixth gear. I don't know for sure, but I think this has something to do with resonance in one of the pipes. Am I wrong??
Sounds EXACTLY like my diff did for 11,000 miles til she let go.
A change to a good quality synthetic fluid will diminish the volume, and add to the longevity factor.
And yes, you need the additive.
09-23-05, 05:40 PM
yes. i had identical problem, went to dealership, and sure as shit, ring and pinion gears worn out in differential. Talk to your dealership, hopefully they won't screw around with you
Try and hold off a little longer tho, then the new diff will be easier to get.
Thanks guys for all of your responses - you guys are really great. I am hoping that I can hold off for the 2006 diff. Any suggestions on how to now maximize the time I have left on this diff. I am currently at about 5600 miles.
Flush the rear diff'. Be sure to use Genuine GM parts. No need to tempt fate by using another brand. Don't forget the additive.
09-23-05, 09:49 PM
Actually, I think the grape scented GM goo is part of the problem. I switched to Lucas (with Cadillac's approval) and the rear end noise disappeared around 90%. I believe Cadillac would have saved a bunch of rear ends if they put in a better fluid and more of it.
It definitely sounds like the rear end is going though on your car. It sounds very familiar. Most dealers won't even deal with it until you can hear it above your radio. Towards the end of my first rear dif's life, it was howling pretty loud. It started to remind me of my 74 Duster's rear end.
if i use redline gear oil, do still use the gm additive....redline says it already has it in there...
I used Lucas syn., and still had to add the l/s additive, so I would say yes.