View Full Version : Help, new rear new whine?

04-07-05, 07:21 PM
Quick question:

I have 750 miles...at 650 Chesrown Newark switched out the rear.

I have been following instructions on breaking in the rear...

I am beginning to hear an EVER so SLIGHT whine. Could this be part of the break in procedure?

I dont think Chesrown would take me for a "ride" if they say they switched the rear...

Any feedback would be great.

Thanks guys.

04-07-05, 08:19 PM
The anti-hop system may be transmitting some noise from the diff into the cabin.

Run 'er until she splinters. :lildevil:

04-07-05, 08:30 PM
I hope so..

Been doing 1-4-6 shifts to stay under 2k rpm...I can't be nicer to the rear.

To my surprise I get WONDERFUL gas mileage but feels like a honda.

04-09-05, 10:45 PM
mine is new also, just put 500 miles on it. the first 300 was all easy acceleration up to 80.. Then I got on it but no clutch dumps, no burnouts.. Slightly whining now between 70-80.. That's exactly how my first rear started, and little by little it got louder and louder.. I would like to be optimistic, but I am afraid I will be back at the dealer in about 2000 more miles.. Very disappointing indeed!

04-09-05, 10:58 PM
Now this is just weird. I have a 2005 that I've been pretty nice to; easy breakin and all, and almost all of my launches are of the rolling variety. But now and then I get on it in first gear and dump the clutch, then climb to redline in 1st & 2nd just to hear the chirps. And then wind in 3rd until 80 or so. I have almost 12K miles now, and not a whisper from the differential, much less a whine.

Is it possible that there's an process problem (or a QC problem) at Getrag, rather than a fundamental design flaw?

04-10-05, 06:39 AM
The howl I hear seems like it is very temp. dependendent. Mine does not howl until the temp. outside is over 75 deg. So now I must wait till summer.

04-10-05, 10:58 AM
maybe thicker gear oil might shut up our rears!

04-10-05, 12:09 PM
I had a nasty growl/whine, at different mph. I put in Lucas 75-90 synthetic and no whine, so maybe the stock fluid is too wimpy. I have since put on an additional 3000 miles since, it did take a couple of hundred miles to get quiet tho.

Danny, as I said, the diff support is going to transmit some noise, but it should not continue to escalate.

04-10-05, 09:00 PM
CTSV05, we may be onto something!!!! I'll give the lucas gear oil a shot. Maybe it will quiet the rear a bit and it may be early enough to prevent damage. I have not even done one burn out or chirped gears, to me that's taking it easy.

Did you add the GM diff additive? Or is it all lucas?

04-10-05, 09:29 PM
Is it possible that there's an process problem (or a QC problem) at Getrag, rather than a fundamental design flaw?

I'm thinking that it may be both. The fundamental design flaw is that you have a differential rated at 310 ft lbs of torque connected to a mill that produced 395 foot pounds. Now I think it is safe to assume that even with losses, there is more torque being delivered to the diff than the diff is rated to handle at whatever rpm gives us the 395 ft lbs.

But, it seems like there are far too many leaky half-shaft seals and far too many "babied" rears blowing for the underating to be the only problem, no? If the rating was the only issue it would only be the racers and the clutch dumpers having trouble, no?

04-10-05, 11:20 PM
Will, I did not add the "whale oil" but have noticed on very slo turning situations some clutch chatter, so I would add it, I will as soon as I get a minute.

04-10-05, 11:23 PM
Thanks, I'll do just that.

Rich H
04-10-05, 11:30 PM
If the rear differential is indeed rated at only 310 ft-lb torque, I think Cadillac may have to deal with more than a few isolated complaints in the future. Time will take its toll and I would expect most to fail sometime - maybe after the OEM warranty has expired. We all put our foot into it now & then - some more than others. Why would we own the car if we didn't? No whine from my rear - yet. But I doubt I could hear it over all the clunking and banging coming from somewhere underneath which the dealer says is normal backlash. Pure BS.

It's hard for me to believe that GM would knowingly install an under-designed drivetrain component realizing this could be the basis for a class action lawsuit.
I think we are all entitled to an extended warranty on every drivetrain component downstream of, and including, the dual mass flywheel. Any good lawyers out there?

04-11-05, 05:49 AM
eeek! not another "class action" thread!

Some might say that the terms "class action" and "good lawyers" are mutually exclusive......

04-11-05, 08:13 AM
eeek! not another "class action" thread!

Some might say that the terms "class action" and "good lawyers" are mutually exclusive......

Wow!!! Don't get me started!!!!:rant2: :madtalkin

I'm not sure how to handle this other than on an individual basis, but, we need to be sure to REMIND our dealers how many have had the same problem.

As I've said many times, we are very fortunate to have a great dealer to deal with.

04-11-05, 04:16 PM
Bad news...

Whine is getting really bad.

I will attempt fluid change...but this just sucks...

Dave's V
04-11-05, 06:10 PM
I have a great dealer. They said they didn't know any problem with the V. (They could be telling the truth since there are not many in the state) I said I could bring pages of forum articles of people that have had problems with the rear end. I guess they can somehow track how you drive the car (a mechanic mentioned it to me). I don't know if it is true, but I wouldn't be surprised if it is.

Well I have about 100 miles left of breaking in the new rear. I usually shift before 3k, always before 4k, never more than 50% throttle, no long cruising. If the rear end fails this time, it either needed the additive that the dealer wouldn't put in (said its not required) or this rear end just sucks.