The Camaro Club (UK)

Hi all,

Time to ask about my second biggest niggle, i have a diff whine that comes in about 60 and is worst at 70, good news is its gone by 80 so thats my cruising speed.

Ive done a bit of research and i know its a common fault, its a UK car with 86k kms on it. Lots of history and no abuse in its past as far as i can tell. Oil was changed about a year ago.

I can live with it and i know it may get no worse for years. Ive even read of some cars doing this from new. But if it can be sorted reasonably id like to do it as i plan on keeping the car.

So if anyone has experience of this id appreciate the feedback.

many thanks,

where to start on this one???

well on a 99 Z28 (my year too) the posi should be a zexel torsen helical gear type, if you want to read about that. You wheels will spin oposite ways like open diff when both off the ground if it has. There are no wearing parts as it were on these so nothing to worry about with regards to any kind of planet gear as they dont have them (or clutches like the auburn type) also you DONT need any limited slip additive in these to make them function but it makes then quieter.

With reagards to the whine, is it loud/quiet, and deceleration or accel or constant speed. As far as im aware its due to a 'bit incorrect' lash setup so the gears dont mesh perfectly. You'd have to pull the diff cover and check the lash to see if it is within recomended specs. I did here that on post 2000 cars many diffs were put in a bit tight so made noise.

I DID worry about this at the start when i got my camaro but now aint too bothered, i swaped out the 'noisy' diff and put in an auburn clutch type more an LSD rather than a posi, this failed after a year of drag racing and 'crappy' oil and was on the verge of detonation when I took it out (the springs were really loose and were hitting the planet gears). Anyway, got another zexel axle from a TA WS6 and put that in, and it was off a 30K car and still makes some noise, but i'm not too worried. it drives fine and when i get it on ramps the noise dissapears and only happens when drving, sod law.

Sorry for mammoth reply but really upto you if you want to leave or sort out. Also a axle on ebay for about 300 if you want another

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'99 Z28 A4, 253 LS2 heads, 228R TSP cam, Patriol Dual Springs, Double roller timing chain, LS6 ported oil pump, OBX LTs, 3" True Duals, LS6 intake, 42lb/hr injectors, SLP lid + bellow, EFIlive COS 3 Speed Denisty Tune (self tuned), 3200 Circle D stall, CAI mod, KYB AGXs, Eibach Pro Front Springs, UMI panhard, LCA + Brackets, Strut Brace, Custom Subframe connectors, WS6 axle with 3.42s, 18" American Racing Rebels, US mirrors, 93 tail lights, 3.5 inch custom cowl hood. Mickey T's Street DRs on Vette-ZR1 wheels for the strip !
Best ET: 12.0 @ 116 mph (on a 0-60ft of 1.8 s)

Thanks for the info i didnt know much about the internals,

The whine is only under load and stops when i lift off the gas, its got no worse since ive had the car.

Its not too bad just a bit annoying is there a particular oil that will quieten it a bit? I believe the previous owner put full syn with additive not long ago.

On a side note the back end has let out a screech when cornering maybe twice since i got it, i cant get it to repeat it so cant trace it.
One time about 3 seconds when i first got the car and just a hint the other day 1500 miles later. Dont know if its related.

Many thanks,

it could be related, my Auburn style one did this a couple of times when the clutches slipped sometimes under heavy load (ie wheels spin) or could be done under cornering, when the clutches dont lock up corect the lock the wheels. But I'd have though you'd have the Zexel diff. Only way to know is to pull the cover and have a look. I cant say the zexel has ever done this. Sorry can t really help much?

Depending on what the 'whine' is then mabe a heavier gear oil or shock resistant gear oil like the redline stuff maybe good, but I just have the standard 75w90 in (I think off top of my head) but is redline and seems ok.

Clearly you exhaust is not loud enough to negate all the other squeeks and rattles of the car

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'99 Z28 A4, 253 LS2 heads, 228R TSP cam, Patriol Dual Springs, Double roller timing chain, LS6 ported oil pump, OBX LTs, 3" True Duals, LS6 intake, 42lb/hr injectors, SLP lid + bellow, EFIlive COS 3 Speed Denisty Tune (self tuned), 3200 Circle D stall, CAI mod, KYB AGXs, Eibach Pro Front Springs, UMI panhard, LCA + Brackets, Strut Brace, Custom Subframe connectors, WS6 axle with 3.42s, 18" American Racing Rebels, US mirrors, 93 tail lights, 3.5 inch custom cowl hood. Mickey T's Street DRs on Vette-ZR1 wheels for the strip !
Best ET: 12.0 @ 116 mph (on a 0-60ft of 1.8 s)

M sure the diff is stock,the noise is over so quick i cant really register it let alone where its coming from.

Speaking of exhaust mine is a stainless back box of unknown origin which sounds ok but is quite modest.
I was thinking of a magnaflow next year but was not sure about drone with them. Whole new topic.

You have a dual setup i think?

yeah exhausts are a hole new topic, i dont buy into all the hype of magna flow this and powerflow that etc etc. All the systems are the same and NOT optimum for power in my opinion. I run a true dual with x-pipe crossower that is 3" from headers. This is way over kill in size for a stock block but cams and head will sort that, its pointless doing the same job twice.

anyways, yeah the diff is prob stock, i dont doubt that but my point is some cars for some reason had the auburn and others the zexel torson. It should be the torson so you shouldn't have any problems. To be honest I wouldn't worry about it too much and just 'see how it goes'

also you need some pictures up of the car dude

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'99 Z28 A4, 253 LS2 heads, 228R TSP cam, Patriol Dual Springs, Double roller timing chain, LS6 ported oil pump, OBX LTs, 3" True Duals, LS6 intake, 42lb/hr injectors, SLP lid + bellow, EFIlive COS 3 Speed Denisty Tune (self tuned), 3200 Circle D stall, CAI mod, KYB AGXs, Eibach Pro Front Springs, UMI panhard, LCA + Brackets, Strut Brace, Custom Subframe connectors, WS6 axle with 3.42s, 18" American Racing Rebels, US mirrors, 93 tail lights, 3.5 inch custom cowl hood. Mickey T's Street DRs on Vette-ZR1 wheels for the strip !
Best ET: 12.0 @ 116 mph (on a 0-60ft of 1.8 s)

Ah, i didnt know they came with two different axles, is there a way to tell one from the other easily?

I do intend to leave it alone as its not so bad, theres as much noise from the tyres at speed and i can do the time honored turning up of the stereo as an additionmal measure.

Someone suggested adding that Activ8 anyone have any experience of it in this application? I wouldnt bother in an engine but maybe in this case it might work.

I agree with the pipe and thought i had few options there but apparently theres a good builder near to me but i need to know what to ask for as he builds from scratch.
Im leaving the motor stock as its my daily toy, the airbox is done but thats it , how do i get the right sound and power without droning if these companys invest millions and still cant?

Thanks.

Photos to be taken when ive cleaned all the crud off that its collected lately, looking a bit dull now but i kinda like the well used look.

not heard of actiV8, presume its like lucas stuff? I've used the lucas in diffs of old landrover I had but kind of a different kettle of fish. I'd go with some redline high impoact stuff if you rally wanted to change oil.

to check the diff jack up the car so both rear wheels off the floor. Spin on and see if the other moves in same direction or oposite. Zexel will act like open diff as it uses torque biasing gears, but a auburn LSD with clutches, both will spin same way.
If its the auburn and 'not at its peak' the other wheel will not move and it may make some squeeking noises.

I'm not doubting magnaflow, borla etc are good and they prob do take out most of the drone? i'm not sure, you'll have to post up about exhausts. I know I speak to pezza on here a lot and he just got a borla so he might have some input. I think they are reasonabbly priced in the US but after importing yourself its too much. I'd rather have some rpm drone for a louder and cheaper system but thats me

search maudyz28 on youtube for my videos. Really old one was when i just cut off UK spec back box and had 2 cherry bomb mufflers put in. The true duals is my set up now. My father is a fabricator so custom made it all. I do get occational scraps with having two 3 inch pipes under and my car is 1-2 inch lower but hey, I just go really , really slow over bumps

_________________
'99 Z28 A4, 253 LS2 heads, 228R TSP cam, Patriol Dual Springs, Double roller timing chain, LS6 ported oil pump, OBX LTs, 3" True Duals, LS6 intake, 42lb/hr injectors, SLP lid + bellow, EFIlive COS 3 Speed Denisty Tune (self tuned), 3200 Circle D stall, CAI mod, KYB AGXs, Eibach Pro Front Springs, UMI panhard, LCA + Brackets, Strut Brace, Custom Subframe connectors, WS6 axle with 3.42s, 18" American Racing Rebels, US mirrors, 93 tail lights, 3.5 inch custom cowl hood. Mickey T's Street DRs on Vette-ZR1 wheels for the strip !
Best ET: 12.0 @ 116 mph (on a 0-60ft of 1.8 s)

Hi,

If you have a posi rear axle and it whines it could be due to having the wrong oil in the diff.

Also, GM posi diffs do require a bottle of additive to be added to the oil. I did this with my thirdgen and it went very much quieter.

Also it will cause a chatter in the rear axle and a squeal when cornering.

Hope this helps.

I added Lubegard to mine. TBH (Sorry it's a bit of a plug) I was so impressed with it I took on the UK agency.

you can see the write ups if you google (I did 21 pages with no complaints listed) and on the website is a report done by a Swiss motoring magazine.

Not cheap but it's much cheaper than replacements!