07-29-2015, 04:42 PM | #1 |
Dimitri
Drives: 68 GTO 455 Ram Air; 2014 Camaro ZL1 Join Date: Jan 2014
Location: Novato, California
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REAR DIFF FLUID SERVICE - DO 8 FIGURE 8's TSB - CHATTER
My 2014 ZL1 has 9,000 miles on it. I get 2 years free engine oil/filter service from dealership. Change engine oil light soon came on yesterday. Today I dropped it off at the dealership. Since it will be racked I asked if they can service the rear diff fluid also. The reason to service rear diff was to get out all that metal shavings out of the rear diff, other than that it worked great.
Service manager told me about a TSB rear diff fibrous clutch chatter. After replacing the rear diff fluid to drive the car in 8 figure 8's or 8 circles to the right and left right a way. If you do not do this it causes a dry spots on the clutch surfaces causing the chatter. I thought this was very interesting. |
07-29-2015, 04:53 PM | #2 |
Dazed &
Drives: matte blue 2014 z28(186) 2015 R1 Join Date: Jun 2013
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thanks for the heads up
i need to change mine and will be doing the figure 8's! |
07-29-2015, 05:12 PM | #3 |
HAMMER PILOT
Drives: 13 ZL1#182, 85 CJ7, 16 Silverado Join Date: Nov 2011
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It's more than just figure 8s, read the tsb.
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07-29-2015, 05:23 PM | #4 |
Dimitri
Drives: 68 GTO 455 Ram Air; 2014 Camaro ZL1 Join Date: Jan 2014
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07-29-2015, 05:30 PM | #5 |
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It doesn't differentiate, the tsb is only for noise.
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07-30-2015, 05:36 AM | #6 |
Drives: 2015 ZL1 Blue Velvet Metallic Join Date: Mar 2015
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OK, so I read the OP meaning that every time you replace your rear diff fluid you need to do the 8 figure 8's so as to not get future chatter from the recent fluid R&R. I think the service manager probably added confusion by informing OP of the TSB, which may not even apply in his case.
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07-30-2015, 06:48 AM | #7 |
Drives: 2017 Mosaic Bk ZL1 M6 Join Date: Jul 2009
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Anytime oil is changed in a limited slip diff you should do figure 8s to make sure the lube is distributed across the clutches to keep them from binding.
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07-30-2015, 07:00 AM | #8 |
Drives: 2012 Chevrolet Camaro ZL1 Join Date: Apr 2015
Location: USA
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The dealer did this for me under warranty. The noise that they used to validate the TSB was a deep whining sound under slow, hard turns. They replicated it and performed the 3x fill and drain with figure 8's for me. Saved me quite a bit of money.
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07-30-2015, 07:49 AM | #9 |
Drives: 02 Z06, 95 Trans Am, 2012 ZL1 Join Date: Mar 2012
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If you aren't having any problems just change the fluid and drive. It will distribute just fine.
Only reason for the dealer to do the figure 8s is to distribute it quickly. Then they are going to drain it immediately and refill x3. They do it that way so they don't have to drive your car 100 miles to complete the TSB.
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08-07-2015, 12:41 PM | #10 |
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Drives: 2014 Camaro SS - 2SS, RS Join Date: Jan 2014
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my 2014 SS/RS M6 made rear-end noise like that since brand new.. I just changed the rear differential fluid and tranny fluid myself a couple of weeks ago, and now there's no more noise..
I had to drive about 10 miles to get to a parking lot where I could do figure 8's.. it drove fine and no noise at all during that 10 mile drive.. but I did the figure 8's anyway just to be safe haha.. tranny and rear end are much smoother and quieter now with the new fluids.. no more noises... have 5600 miles on my car.. |
08-07-2015, 01:02 PM | #11 |
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Completely different rear end.
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08-07-2015, 06:49 PM | #12 |
Drives: 02 Z06, 95 Trans Am, 2012 ZL1 Join Date: Mar 2012
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Different ratio and larger ring gear, and larger case. But works exactly the same.
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08-07-2015, 07:14 PM | #13 |
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Plus upgraded half shafts, basically a completely different rear end. It may function the same, but so do most engines and they all have different problems. The point I have been trying to make is this is a very common issue, I have had it twice, plus I have had the backlash issue. The TSB is specific to the ZL1 and is more than just figure eights, there is a copy of the TSB somewhere here. Basically if you have a ZL1 and it makes noise from the rear when you are slowly turning, especially in colder temps, you need the TSB. If your ZL1's rear makes sound when decelerating, chances are the backlash is off and the ring and pinion will need to be replaced. This is also a common issue. If you search through the forum this topic has been heavily talked about.
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08-07-2015, 08:40 PM | #14 |
Drives: 02 Z06, 95 Trans Am, 2012 ZL1 Join Date: Mar 2012
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My point is that even though it is heavy duty diff, it functions just like his SS rear diff and if his rear end whirrs or chatters it's the same fix. Change the fluid with some good quality LS diff oil.
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