Rear diff - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

winterboy8 · 08-14-2015, 01:01 PM

Wow, so I've been on the forum since before I ordered my '15 ZL1 researching and reading up on things. I did see a lot of people commenting about the rear end noise. So, when I picked mine up back at the end of may, I too noticed the whine noise during straight line accel/decel and it was most noticeable when you pushed in the clutch and removed all load off the drive train at about 45 mph +/- 10 or so. I told the salesman about it and he said not to worry too much and let's address it at the 1500 break-in service. I was like, ok, seen this on the forum and doesn't sound like a big deal.

Today I finally get the break-in complete, bring in for an oil change and ask them to check out the noise. The put me in a loaner as they said they needed time to investigate. I just got a call from them saying the rear end is completely shot and they are going to order a completely new rear diff. I'm not entirely sure he means the housing/pumpkin as much as I think the ring and pinion gears, but I'll be sure to get those details when I stop by later to pick up some of my items from the car.

I miss my car already and now I'm worried I'm gonna have to do another break-in for the new rear diff. UGH!!! At least they addressed the problem and didn't blow me off. Kudos to Rosner for good service.

Roto-fab and ARH headers are now on hold for at least another week.

willhe64 · 08-14-2015, 01:04 PM

Same thing happened with my 6.2l Silverado, new. They replaced the gears and it still whined. Turned out the housing was off spec. I bet that is why yours went and having them replace the whole unit is your best bet.

BTW. when I test drove it I made it 20 feet and told the salesman "hear that? Rear end is borked dude" he said they all sound like that. I said we could jump in any one of the dozens on your lot and are you sure they all sound like this. He changed his tune.

winterboy8 · 08-15-2015, 02:57 PM

I spoke to the tech and they said it's less risky and costly to try and fix so they want to change the entire assembly.

I asked him if the new rear needed a break in and he thought no, so I'm asking you guys if you think this is correct.

Thoughts?

Sven59 · 08-15-2015, 03:30 PM

There was a thread a couple years ago and a machine shop guy made a very good case for break in. He basically said you will get metal shavings and clearing them out can't hurt. Especially since the ZL1 has a history of noise in the clutch packs which has been possibly attributed to excess lashing compound. I had to have the ZL1 TSB done twice to clear it. I also had the ring and pinion replaced because the backlash was off. The good thing is this rearend is bombproof. GM did over 800 hard launches on one to prove it.

jessrayo · 08-15-2015, 03:41 PM

Break it in at the road course under WOT that is my opinion. Change the fluid after you beat on it and if anything came loose you will flush it out. simple.

ZO6 Bryan · 08-15-2015, 10:53 PM

Quote:

Originally Posted by Sven59

There was a thread a couple years ago and a machine shop guy made a very good case for break in. He basically said you will get metal shavings and clearing them out can't hurt. Especially since the ZL1 has a history of noise in the clutch packs which has been possibly attributed to excess lashing compound. I had to have the ZL1 TSB done twice to clear it. I also had the ring and pinion replaced because the backlash was off. The good thing is this rearend is bombproof. GM did over 800 hard launches on one to prove it.

Define "lashing compound".
No such thing.

Sven59 · 08-15-2015, 11:28 PM

I guess it is marking compound, some service techs called it lashing compound. Maybe their word for it.

ZO6 Bryan · 08-16-2015, 12:22 AM

Quote:

Originally Posted by Sven59

I guess it is marking compound, some service techs called it lashing compound. Maybe their word for it.

Actually the only place that the term "lashing compound" has ever been used is on Camaro5. Heresay from one guy getting "maybe" info from a tech at the dealer that didn't even get the name right. I don't buy it at all.

Basically comes down to a common problem with ALL limited slip diffs for decades that needs nothing more than a fluid change and maybe some limited slip additive to correct. Not a new problem at all.

The TSB calls for a couple of fluid changes just to make sure all the old stuff is gone. Never had anything to do with gear marking compound.

Rant mode off.

Sven59 · 08-16-2015, 12:46 AM

Does it really matter? It's the yellow sh!t on the ring and pinion. By the way did you read the TSB for the ZL1 only. And you are positive that lashing compound has never been used except on Camaro5? Lol. Because the hashing of a word is the most important thing in the world right now.

ZO6 Bryan · 08-16-2015, 08:33 AM

Quote:

Originally Posted by Sven59

Does it really matter? It's the yellow sh!t on the ring and pinion. By the way did you read the TSB for the ZL1 only. And you are positive that lashing compound has never been used except on Camaro5? Lol. Because the hashing of a word is the most important thing in the world right now.

Of course I've read it. No where is there a mention of gear marking compound.

BTW "valve lashing compound" is used to get the final seal on valve seats in the heads. Has nothing to do with the rear diff.

Show me any documentation of marking compound being the culprit in the ZL1.
There is none.

jrhagen · 08-16-2015, 08:49 AM

Cock fight.

jayno20 · 08-16-2015, 11:02 AM

Quote:

Originally Posted by Sven59

Does it really matter? It's the yellow sh!t on the ring and pinion. By the way did you read the TSB for the ZL1 only. And you are positive that lashing compound has never been used except on Camaro5? Lol. Because the hashing of a word is the most important thing in the world right now.

A quick Google search shows that on the internet it hasn't really been used anywhere except here...

JKPHX · 08-16-2015, 12:21 PM

Quote:

Originally Posted by ZO6 Bryan

Actually the only place that the term "lashing compound" has ever been used is on Camaro5. Heresay from one guy getting "maybe" info from a tech at the dealer that didn't even get the name right. I don't buy it at all.

Basically comes down to a common problem with ALL limited slip diffs for decades that needs nothing more than a fluid change and maybe some limited slip additive to correct. Not a new problem at all.

The TSB calls for a couple of fluid changes just to make sure all the old stuff is gone. Never had anything toh do with gear marking compound.

Rant mode off.

Anybody have have a copy of this tSB? I have a 2015 zl1 and my dealer cant seem to locate it. I don't have a loud rear different sound but should I replace the rear different fluid anyway (at 5k miles)?
,

winterboy8 · 08-16-2015, 12:43 PM

OK, so aside from using the yellow stuff while your examining where the gears mesh between the ring and pinion gears, did anyone have any thoughts on the new set that will be installed? i.e. does anyone think there will be any lengthy "required" break-in from GM on the part? I'm just quite over keeping this thing under 80 mph, which is the only part of the break-in I can think that would apply to the rear end gears.

Thanks guys.

08-14-2015, 01:01 PM	#1
winterboy8 Drives: 2015 ZL1 Blue Velvet Metallic Join Date: Mar 2015 Location: Melbourne, FL Posts: 720 View My Garage	Rear diff Wow, so I've been on the forum since before I ordered my '15 ZL1 researching and reading up on things. I did see a lot of people commenting about the rear end noise. So, when I picked mine up back at the end of may, I too noticed the whine noise during straight line accel/decel and it was most noticeable when you pushed in the clutch and removed all load off the drive train at about 45 mph +/- 10 or so. I told the salesman about it and he said not to worry too much and let's address it at the 1500 break-in service. I was like, ok, seen this on the forum and doesn't sound like a big deal. Today I finally get the break-in complete, bring in for an oil change and ask them to check out the noise. The put me in a loaner as they said they needed time to investigate. I just got a call from them saying the rear end is completely shot and they are going to order a completely new rear diff. I'm not entirely sure he means the housing/pumpkin as much as I think the ring and pinion gears, but I'll be sure to get those details when I stop by later to pick up some of my items from the car. I miss my car already and now I'm worried I'm gonna have to do another break-in for the new rear diff. UGH!!! At least they addressed the problem and didn't blow me off. Kudos to Rosner for good service. Roto-fab and ARH headers are now on hold for at least another week. __________________ Roto-Fab CAI, ARH LT, SW 3" catback, JRE tune, Elite-2 CC, VMAX TB, Big Gulp, WW II relo, Lingenfelter S/C reservoir

08-14-2015, 01:04 PM	#2
willhe64 Drives: 2012 45th Vert, 2011 4x4, 9sec Vega Join Date: Mar 2012 Location: Canada Posts: 2,188	Same thing happened with my 6.2l Silverado, new. They replaced the gears and it still whined. Turned out the housing was off spec. I bet that is why yours went and having them replace the whole unit is your best bet. BTW. when I test drove it I made it 20 feet and told the salesman "hear that? Rear end is borked dude" he said they all sound like that. I said we could jump in any one of the dozens on your lot and are you sure they all sound like this. He changed his tune. __________________ I feel it only fair to warn you, I have a black belt in CAPS LOCK.

08-15-2015, 02:57 PM	#3
winterboy8 Drives: 2015 ZL1 Blue Velvet Metallic Join Date: Mar 2015 Location: Melbourne, FL Posts: 720 View My Garage	I spoke to the tech and they said it's less risky and costly to try and fix so they want to change the entire assembly. I asked him if the new rear needed a break in and he thought no, so I'm asking you guys if you think this is correct. Thoughts? __________________ Roto-Fab CAI, ARH LT, SW 3" catback, JRE tune, Elite-2 CC, VMAX TB, Big Gulp, WW II relo, Lingenfelter S/C reservoir

08-15-2015, 03:30 PM	#4
Sven59 HAMMER PILOT Drives: 13 ZL1#182, 85 CJ7, 16 Silverado Join Date: Nov 2011 Location: Tucson AZ Posts: 4,387	There was a thread a couple years ago and a machine shop guy made a very good case for break in. He basically said you will get metal shavings and clearing them out can't hurt. Especially since the ZL1 has a history of noise in the clutch packs which has been possibly attributed to excess lashing compound. I had to have the ZL1 TSB done twice to clear it. I also had the ring and pinion replaced because the backlash was off. The good thing is this rearend is bombproof. GM did over 800 hard launches on one to prove it. __________________ "DO YOU WANT ME TO PUT THE HAMMER DOWN?"

08-15-2015, 03:41 PM	#5
jessrayo Speed Freak Drives: 2013 ZL1 Camaro, 2016 Camaro SS Join Date: Jun 2013 Location: Ardmore, OK Posts: 2,637 View My Garage	Break it in at the road course under WOT that is my opinion. Change the fluid after you beat on it and if anything came loose you will flush it out. simple. __________________ 2016 SS -AGP twin Borg Warner 7163 EFR's, LT4 mechanical pump, LT4 injectors, Walbro 255 low side, Castrol SRF. 734whp/759 tq 2013 ZL1 -ADM - 427 LSX 6 bolt, O-ringed block built by LME. Twin PT6466 turbos. RPM custom manual trans, RPS Quad carbon clutch, 9" Hendrix rear diff & axles. ADM/squash fuel system, Ron Davis radiator, Spal fans, AGP air to air, turbo plumbing. LPE oil cooler, rear bushing upgrade, roll bar...etc. rwhp 1400+... 212.5mph, best Texas mile to date.

08-15-2015, 11:28 PM	#7
Sven59 HAMMER PILOT Drives: 13 ZL1#182, 85 CJ7, 16 Silverado Join Date: Nov 2011 Location: Tucson AZ Posts: 4,387	I guess it is marking compound, some service techs called it lashing compound. Maybe their word for it. __________________ "DO YOU WANT ME TO PUT THE HAMMER DOWN?"

08-16-2015, 12:46 AM	#9
Sven59 HAMMER PILOT Drives: 13 ZL1#182, 85 CJ7, 16 Silverado Join Date: Nov 2011 Location: Tucson AZ Posts: 4,387	Does it really matter? It's the yellow sh!t on the ring and pinion. By the way did you read the TSB for the ZL1 only. And you are positive that lashing compound has never been used except on Camaro5? Lol. Because the hashing of a word is the most important thing in the world right now. __________________ "DO YOU WANT ME TO PUT THE HAMMER DOWN?"

08-16-2015, 08:49 AM	#11
jrhagen Banned Drives: Camaro Join Date: Mar 2013 Location: USA Posts: 2,701	Cock fight.

08-16-2015, 12:43 PM	#14
winterboy8 Drives: 2015 ZL1 Blue Velvet Metallic Join Date: Mar 2015 Location: Melbourne, FL Posts: 720 View My Garage	OK, so aside from using the yellow stuff while your examining where the gears mesh between the ring and pinion gears, did anyone have any thoughts on the new set that will be installed? i.e. does anyone think there will be any lengthy "required" break-in from GM on the part? I'm just quite over keeping this thing under 80 mph, which is the only part of the break-in I can think that would apply to the rear end gears. Thanks guys. __________________ Roto-Fab CAI, ARH LT, SW 3" catback, JRE tune, Elite-2 CC, VMAX TB, Big Gulp, WW II relo, Lingenfelter S/C reservoir