Rear end noise
Thread Starter
Burning Brakes
Joined: Jan 2022
Posts: 1,186
Likes: 660
From: Iowa
Rear end noise
I have an 07 base with 20k on it. Diff fluid was changed last spring using ac delco 75/90. Recently I'm having a noise from what I think is the rear diff. Upon starting the cold vehicle if I turn the wheels sharp......ish to the left or right(pulling out of a parking spot that i backed into) it makes what sounds like a tire rubbing noise and is a little jerky. The feeling is similar to the front tires scrubbing in cold weather but it definitely is coming from the rear. It's only a few seconds and will not repeat itself until the car sits for a bit. Any ideas what this could be? Is it normal?
Thread Starter
Burning Brakes
Joined: Jan 2022
Posts: 1,186
Likes: 660
From: Iowa
I was unaware there was 2 different ones and I didn't do it. Paperwork only shows 75w-90 with no part number. If the wrong one was used wouldn't it start doing it sooner? Car has roughly 8k on it since fluid change, but just started doing this a couple months ago.
Le Mans Master
Joined: Dec 2004
Posts: 5,492
Likes: 808
From: West coast CA
I have never used the other one, but it looks like a replacement for the old non-LS gear oil. Apparently it has a "grape scent." The right one has a... terrible scent. You could open the fill plug and take a sniff but if there's any mixed with the other who knows what it will smell like.
Safety Car
Joined: May 2016
Posts: 4,667
Likes: 1,849
From: Erlanger, Kentucky
I have an 07 base with 20k on it. Diff fluid was changed last spring using ac delco 75/90. Recently I'm having a noise from what I think is the rear diff. Upon starting the cold vehicle if I turn the wheels sharp......ish to the left or right(pulling out of a parking spot that i backed into) it makes what sounds like a tire rubbing noise and is a little jerky. The feeling is similar to the front tires scrubbing in cold weather but it definitely is coming from the rear. It's only a few seconds and will not repeat itself until the car sits for a bit. Any ideas what this could be? Is it normal?
Thread Starter
Burning Brakes
Joined: Jan 2022
Posts: 1,186
Likes: 660
From: Iowa
Nothing worse than people who don't update threads like these so here's the update. Fluid in diff was changed last spring and shortly after is when the problems started but it was minor. It got worse and did it loudly on every sharp turn. Took the car to another shop and stated I wanted the Fluid changed and gave them the part # to the Fluid I wanted put in. They didn't do that. They used the Fluid that requires friction modifier to be added instead of the premixed Fluid. No change initially but after some figure 8s and a few hundred miles it's back to being quiet. I'm convinced the first shop that did the Fluid swap put the wrong fluid in. Hopefully it stays quiet for a while.
Melting Slicks
Joined: Apr 2019
Posts: 2,512
Likes: 1,166
From: Northern Wisconsin
Nothing worse than people who don't update threads like these so here's the update. Fluid in diff was changed last spring and shortly after is when the problems started but it was minor. It got worse and did it loudly on every sharp turn. Took the car to another shop and stated I wanted the Fluid changed and gave them the part # to the Fluid I wanted put in. They didn't do that. They used the Fluid that requires friction modifier to be added instead of the premixed Fluid. No change initially but after some figure 8s and a few hundred miles it's back to being quiet. I'm convinced the first shop that did the Fluid swap put the wrong fluid in. Hopefully it stays quiet for a while.
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Racer
Joined: Sep 2001
Posts: 365
Likes: 93
From: Chesterfield VA
It is ok. Now you know the posi is working. When it is cold there is no oil in the clutches, as the diff moves it will sling oil into them and this sensation and noise will go away. If it does not then change the oil or you can add an additive to it.
Melting Slicks
Joined: Mar 2023
Posts: 2,939
Likes: 1,692
From: North Coast
I would like to update this. I was looking to change my C5 oil and there is a lot of confusion as to what oil to use in what car and model. GM is not real clear on this. I contacted my contact at Scoggin and Dicky the GM performance Dealer in TX for clarification.
10-4016 Will work in any year of Corvette. It contains no LS additive and most applications will require one bottle of additive. If you still have a popping or snap sound add a second bottle.
10-4034 is for Corvettes 2007 and later and is most what they have to put on all warranty work. It does have the LS additive but again in some cases depending on how tight the springs are a second bottle may be required. From my understanding this oil was to address some TSB issues. So both will work and both are fine.
The one thing is the additive and some rears are tighter than others and that is why some will take a second bottle if there is still noise.
I hope this clears up some stuff going round on the web. It makes sense once he explained.
This is also why the Corvette shops on line will sell one or the other. They both will work. Note The 10-4016 is a little more heavy duty for temps and high speed.
GM or Delco needs to really clean this up. The info out there is really poor on this stuff,
10-4016 Will work in any year of Corvette. It contains no LS additive and most applications will require one bottle of additive. If you still have a popping or snap sound add a second bottle.
10-4034 is for Corvettes 2007 and later and is most what they have to put on all warranty work. It does have the LS additive but again in some cases depending on how tight the springs are a second bottle may be required. From my understanding this oil was to address some TSB issues. So both will work and both are fine.
The one thing is the additive and some rears are tighter than others and that is why some will take a second bottle if there is still noise.
I hope this clears up some stuff going round on the web. It makes sense once he explained.
This is also why the Corvette shops on line will sell one or the other. They both will work. Note The 10-4016 is a little more heavy duty for temps and high speed.
GM or Delco needs to really clean this up. The info out there is really poor on this stuff,