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View Full Version : How Much Should A Limited Slip Clunk?



Alpine CDA-9815
10-18-2007, 07:55 PM
In the last 6 months my rear end has got quite loud. I know with a limited slip it will will clunk and whine... but how much should it? I know of 3 other buds of mine with the same issue, they say it's normal but their cars are not near as bad as mine.

It has always whined and clunked from the factory. Though since we installed the stage 5 tranny it has gotten worse and worse. The worst is usually when I go slow and turning hard. It will clunk and jerk everytime the driveshaft makes a full spin. It now also clunks and whines bad when I take my foot off the gas going 40+ MPH. Then the whine from 38-42MPH has gotten twice as loud.

I changed the rear end fluid after getting 500 miles on the car to Royal Purple. I even added about an ounce of GM limited slip even though RP says it's not needed.

I don't really have a lot of money to fix it and I don't want to pay to have someone look at it unless I have to, or start replacing parts that are not needed. The shop I usually go to just says not to worry about it... but they are lazy and just don't want to look at it. Other shops think it could be the clutch packs or it could be something wrong with my rear cradle.

I'm wanting to take this thing to the track, I have not in over a year. The best I have done so far is 12.00 @ 115mph with a 1.9 60'. Since then I've added almost a full suspension, the stage 5 trans, electric water pump and nitrous (150-175 shot). I don't really abuse the car and I have gone through only one 10lb bottle of nitrous since I have gotten it @ 150 shot.

azbass
10-18-2007, 07:59 PM
I dare you to take it to a dealership..

Alpine CDA-9815
10-18-2007, 08:07 PM
I dare you to take it to a dealership..
I could do that. I do have some connections down there, they have already done warranty work they did not have to do for me already. Though I don't know any managers at any dealers anymore. So the guy that I would go through would have to get the work passed by his manager befor he could do it... I don't think that would go too well lol.

Silver
10-19-2007, 11:03 AM
That is NOT normal even from the factory. Get it replaced before it really puts you at the side of the road.


I dunno how loud it is, but the radio should be up a little more than 1/4 and driving at 45mph. If you can still hear whinning def get a new one.

Getrag rear end? If so, the dealership would not hesitate 1 bit to replace that. They blow left and right. Last week I did 3 getrags in Cadillac CTS's. I did one in a V, but that was due to nitrus snapping halfshaft and pinion cracking.

The clunking when your turning is spider gears. The clunking when your slowing from 40 is your pinion gear contacting the final drive gears.

Alpine CDA-9815
10-22-2007, 03:13 AM
That is NOT normal even from the factory. Get it replaced before it really puts you at the side of the road.


I dunno how loud it is, but the radio should be up a little more than 1/4 and driving at 45mph. If you can still hear whinning def get a new one.

Getrag rear end? If so, the dealership would not hesitate 1 bit to replace that. They blow left and right. Last week I did 3 getrags in Cadillac CTS's. I did one in a V, but that was due to nitrus snapping halfshaft and pinion cracking.

The clunking when your turning is spider gears. The clunking when your slowing from 40 is your pinion gear contacting the final drive gears.
Can't rememeber if it's a getrag or not, the shop said something about that but didn't say if it was for sure or not.

If you think the dealer will replace it even with my mods I'll give that a shot. There are a few small aftermarket parts I would want installed, I'm sure if I bought them they would use them instead of the OEM parts?

jonnybusa
10-30-2007, 01:38 PM
well, from the factory its not normal. Now, depending on the aftermarket one you installed, they make minimal noises....nothing real noticeable though. Sounds like somethings off. I have a full locking detroit locker, which bangs, clunks, and chirps going around corners, etc, but a limited slip is supposed to be stock-like.

jdawg
10-30-2007, 01:47 PM
Limited slip shouldnt make any noise. If it is then you have problems. If you dont use the addative it will make noise but I see you are so you have problems.

Alpine CDA-9815
10-30-2007, 05:19 PM
I will call the guy at the dealer today or tomorrow and see what he can do for me. There are a few TSB's about a rear ends now that I look into it. I really don't see how the dealer can deny the warrant work when it's this bad, even with my mods. It's my DD, I don't abuse it and if they think I do they gotta prove that my mods or abusing caused the rear end to be the way it is.

Though if they are ***** about it a bud of mine has a whole rear end I could grab for a few hundred bucks and swap it out in an hour.

Alpine CDA-9815
10-31-2007, 01:25 AM
Called the dealership I normally go to. I was told they are no longer allowed to work on any vehicles but Chevy's (since that is only what they sell) unless you bought a used vehicle from them? So now I have to find a new dealer to go to.

Also I decided I would try to change the fluid from Royal Purple to GM stuff with the limited slip additive. The rear is noisier than ever and grinds now.... what a waste of $75.

Ferendon
10-31-2007, 03:17 AM
Time for a steep Cusco. :D

dbhittin
10-31-2007, 03:19 AM
1.5ways and 2ways make clunking noises.. stock lsd's dont.. 2ways is basically fully locked.. i had one before and a welded diff.. mine both hummed.. but ya a stock lsd shouldn't make any noise

Ferendon
10-31-2007, 03:32 AM
A stock LSD probably isn't going to hold that level of power either.

Alpine CDA-9815
10-31-2007, 07:37 PM
I just gotta find a good dealership to go to, that will not be easy.

Alpine CDA-9815
11-01-2007, 05:51 PM
Well I called one a few local guys suggested and the car is going in on Sat at 10am. I told them about the aftermarket cam and exhaust, they said that will not be a factor ATM and that will be decided on when they inspect the car.

Alpine CDA-9815
11-04-2007, 06:10 AM
GM replaced my rear diff.

Ignatowski
11-04-2007, 10:39 AM
Pull the cover and look to make sure everything is clean
If all is good go back racing.....Alot of POSIs clunk like mad
on turns,perfectly normal.,....you can try to add some GM Limited Slip
oil if you like which might make it a little quieter....

Alpine CDA-9815
11-04-2007, 01:06 PM
The old one seriously sounded like it was gonna fall off the car, I didn't feel that safe with it. GM took care of me and replaced it, of course I had to ***** to them to get them to do it. They were nice enough to understand and no managers were there today so they lied about my mods... "only headers and exhaust" ;)

The new rear diff is still whiny and clunks at shifts. I'm going to change the fluid today since I put a few hundred miles on it yesterday and see if that helps. I'll probably also have my trans guy turn down the line pressue on the tranny, it does not shift super hard... enough to churp them from 1st to 2nd at WOT but other than that it's mild.