RAP

Only occassional chatter from the passenger seat when occupied.

mbonness

Yeah, I considered that too, if it's so important to break in the diff by doing the figure eights why don't they just perform this right there at the factory? I've heard that they take certain cars out on the road/highway to troubleshoot issues, so why don't they just put all cars on a dyno-type rig and turn the wheels in both directions to simulate the figure eight breakin procedure. Maybe they don't want to put too much mileage on the new cars and scare away potential buyers who want 0 miles on their cars, I don't know.

Bottom line, we need independent confirmation from a source at the BG plant what they are doing to break in the rear diff, if anything. Without any hard data or facts on what is going on all we have now is a lot of wild speculation on what might or might not be causing the problem...

mbonness

Some interesting info I found from the KAAZ USA website which seems to support my claim that this is a break-in related issue, and is also consistent with the owner's manual recommended break-in procedures which advise against WOT etc.:

"...LSD needs to be broken-in to seat the clutch plates. Applying too much torque when the unit is new will cause damage to the clutch plates and may result in plates forming a angle fit. Once these plates form an angle fit, the LSD is unable to function at 100% efficiency. This will also result in more chattering noise under low speed turns."

Newton06

Purchased 9/18/04: Diff noise occurred & dealer changed oil per TSB.

Much better, but not entirely gone.

If it gets worse, I'll have them replace the clutch packs.

Tommy D

2005 A4 built January 2005 no chatter

BOB'S C6

Mine was built Feb 2005 and had the terrible chatter and even wheel hop,changed fluid and seams to be working.Time will tell.

FAA-ATC

I have been wondering about this for some time. When I got my NCM delivery 1/31/06 I had read all the "vary your speed" stuff posted on here for months, but had somehow not really considered about the turning or going straight part of it. Driving back to the Atlanta area, Interstates all the way, even varying speeds as much as I could without getting in the way, it was still mostly in a straight line. Then I read in the GM TSB about doing the fluid changes then driving in figure 8's a few times to get the fluid in all the right places. I wonder... do NCM delivery folks who drive home on the Interstates have a higher incidence of chatter later? I wouldn't be at all surprised to find out that it is a valid part of the big picture. Owners who take delivery at a dealer and drive home, then to work, whatever, all on non-Interstate streets, probably give their differentials more turning and varied speeds. What do y'all think?

Edit: mine is chattering like a monkey with 12,300 miles.

mbonness

I thought about this also, those who drive cross-country immediately after taking delivery putting on more highway miles driving in a straight line, etc. Mine was a local delivery and I developed the problem after doing mostly non-highway driving so I don't think this is the cause. One of my club members did NCM delivery and he doesn't have the noise yet. So I think we're back to how you drive the car in the first 500 miles - if you drive it too hard, the clutch plates don't form the correct fit and now you have axle chatter.

An interesting point about NCM delivery though, part of the plant tour includes them showing the test track where they drive all new C6s for 4 miles or so. I would be very interested to find out if this initial drive includes driving the car in figure 8s. Maybe if someone is going to BG they could ask the tour guide to get the lowdown on this...

VetteMark

I started getting the chatter around 4500 miles and only when I am turning somewhat sharp and cold as I pull out of the garage! Once I getout to the main drag . . . about two miles . . . the chattering has disappeared on any turns. I had a 100 mile interstate drive home from the dealer just before Christmas and drove it in mixed situations varying everything from speed to road straightness with lots of shifting to insure a good driveline breakin.

I believe it is a differential issue, not a clutch issue! Seems to be dry gears and goes away once the lube has spread.

SASprof

i took local delivery and drive 3 miles 1-way to work. i followed break-in instructions to the letter. rear axle thunk during cold turns began at 3,000 miles and progressively worsened. dealer just changed fluid. much better now.

anothercrisis

Took delivery of my Mn6 in Nov of 2004. No chatter or noise noticed.
12 k miles to date.



anothercrisis

mbonness

Just to clarify when we refer to "clutch plates" in the context of rear axle chatter, these are a part of the differential and are not to be confused with the clutch that is part of your engine transmission.

Thanks for continuing to vote in the poll guys and I appreciate the input from everyone who responded in the thread too.

2LT-Z51

5600 miles and only with the windows down and in a quite parking lot i can hear it starting to chatter.... changing the fluid this weekend hope it helps....

THIS FORUM IS GREAT!!!!!!!

Rear Axle - FAQ

prs62

MN6, Z51 built 11/18/04, 12,000+ miles no chatter.

jdowen

Do the dealers charge to drain and replace the fluid and additive

Vet

No, they shouldn't... it is a known problem covered by the TSB and is under warrantee. Some here HAVE been charged for this though - or in other words, ripped off.

Many owners, such as myself, opt to change the oil themselves to avoid encountering any further damage to the car by careless dealer employees. The non-synthetic GM oil and additive needed is pretty cheap, the work itself is easy as long as you can get your car up off the ground a bit.

DIY on how to change your axle fluid:
http://forums.corvetteforum.com/show....php?t=1497063

Latest TSB - print and bring to your dealer if you plan to go this route:
http://forums.corvetteforum.com/show...24&postcount=2

06LS2

Also a build date of 11/05. Only while backing out of my garage while the car is cold. Intermittent, so like 06C6Z, will wait for any other problems before going to the dreaded dealer.

cg205

I have to wonder about the accuracy of the poll numbers. The other day, I voted 'no chatter' (built before 12-05).

After reading all the posts, though, something occurred to me. On several occasions in the morning when cold, I back out of the garage, turn sharp right to go up drive, and it feels like I've either driven over some boards, or something is wrong with the steering. After experimenting, I'm convinced I have the chatter. It goes away quickly, but will be there again the next morning if I pay attention to it.

Maybe a lot of people have it, and because they don't have to make the hard turns when cold in the morning they don't know it, or, as in my case, they are misinterpreting the symptoms.

I have 7500 miles on my '05.

Hoonose

Same thing happened to me. I guess we have a problem we just didn't know about.

SunsetC6

Got the rattle and did the fluid change. Corrected for a bit but came back. Next is going to be clutch pack change next week. Car only does it when turning slow like parking in a lot. Does fine on the highway and no problems coming to Road Atlanta this morning. Results will follow.