Noisy diff with Amsoil SVG 75W90 2001 Camaro

[9c1lt1]

I just changed the factory diff fluid in my '01 Chevy Camaro LS1 to Amsoil SVG 75W90 and it seems to make a lot more noise than it used to, especially in turns. It is difficult to describe but is sounds like a screeching sound. I did not add any LS additive because it is a Zexel Torsen that uses gears instead of the traditional clutch and cone type. Mileage is 5000 and everything looked normal when I had the cover off. Any help or ideas would be greatly appreciated. Thanks.


Sean

 

[unDummy]

Check the level.
LSD additive isn't necessary here.
I doubt that Amsoil is causing any issues.
Them Camaro 'ends aren't too tough, or is the SBC just too strong. I would've used the 110 or 140 weight especially in that desert location.

 

[Pablo]

Yes - you should be using 75W-110 minimum.

Amsoil SVT 75W-110

 

[Mike_dup1]

The factory recommends 75W-90 so it should not need 110 or 140.

I ran the Amsoil (Series 2000 75W-90) in my 2002 Trans AM WS6 for 4 yrs and never had an issue with noise or anything. I did not use any additive with it.

I hope you did not use any solvent to clean out traces of the old gear lube?

I have the Severe Gear in my 2005 CTS LSD and in my 2008 GMC Locker, no issues whatsoever.

 

[Titan]

Pablo gave me a good update on gear lube "weights" yesterday. I, too, had a noisier differential with 75-90 in a vehicle that is spec'd for it. Should have used 75-110. I just sucked 1/4 of it out, and replaced with 75-140...now it is MUCH quieter.

 

[unDummy]

Factory recommmendations many times are worthless. Shore up a weak or worn 'end with a thicker gear oil. Quiet a noisy end with thicker gear oil. Its too simple not to try prior to tearing into the end.

 

[Bluestream]

Originally Posted By: unDummy
Factory recommmendations many times are worthless. Shore up a weak or worn 'end with a thicker gear oil. Quiet a noisy end with thicker gear oil. Its too simple not to try prior to tearing into the end.


Well said!

 

[mechtech2]

Why a 75-110 MINIMUM?
How about sawdust instead?

 

[Bluestream]

When the factory specs an oil it has to be a spec that will cover the majority of conditions that the vehicle may encounter. That does not mean it's right for your application. A heavier gear oil will make your diffy last longer, but it will cost you in MPG. My BMW owners manual specs "any good quality gear oil" for my 4:11 LSD rear end. When I enquired for more infomation I got this reply from BMW:

Our Technical Department explains that what you need to be concerned about
is the additives present in the Final Drive Oil for Limited Slip and not the
weight. For the Final Drive Oil for Limited Slip, we recommend SAF-XJ.
Unfortunately, we do not provide detailed specifications about the make up
of BMW Operating Fluids."

 

[9c1lt1]

Hmmm, this is getting quite expensive. Would I be better off with the 75W140 or the 110? I do occasionally drag race the car sometimes. I did use non-chlorinated brake clean to rinse out the junk that was in there from the short 5000 mile stint, was I wrong in doing that? Can I get away with conventional even though GM recommends synthetic?

Sean

 

[Titan]

expensive? To save money, I would NOT spend the money on the brake cleaner, and I'd run a synthetic, like AmSoil, one step up from your manufacturer spec. In this case, 75w110. I do not think it would hurt to use the 75w140...if your fuel use increases, I doubt it would be sufficient to be detected.

If you really want to save money, drain/aspirate about half of the 75w90 out, and replace with 75w140. You'll end up with something between the two...which sounds like just what you need. Save the 75w90 fluid you drained out, and mix it equally with your left-over 75w140, and keep it for your next differential fluid change....although, with AmSoil in there, you'll be able to go a LONG time without changing.

 

[ConfederateTyrant]

Since the gear oil weights changed recently, several manufacturers have yet to replace their 90 weight recommendations with the proper 110 weight. Reason being, a 90 weight could be the same viscosity as a 110 weight gear oil.

Do as Titan mentioned, try to drain out a quart or so of the Amsoil and add in the 75w-140 to thicken it into the proper range. You're not the first to have this happen.

 

[9c1lt1]

Actually, I only meant expensive in that I thought I was "wasting" money by just draining the 75W90 and filling with 75W140 which I will do if it will return the noise level back to what if was before. I just hated to see good gear oil go to waste, that's all I will do as Titan says and report back. Money isn't much of a concern, sorry for my confusing reply earlier. This car only gets about 3000 miles/year on it.

 

[chucky2]

I read somewhere for some Torsen - maybe it was the type in my Ranger? - that the LSD additive was used to combat a "rusty screw noise" condition that sometimes came up. Not using the LSD additive wouldn't harm anything, you'd just have to put up with the noise.

Chuck

 

[dailydriver]

Originally Posted By: chucky2
I read somewhere for some Torsen - maybe it was the type in my Ranger? - that the LSD additive was used to combat a "rusty screw noise" condition that sometimes came up. Not using the LSD additive wouldn't harm anything, you'd just have to put up with the noise.

Chuck


Yes, I have heard of dealers adding the GM friction modifier to T2 10 bolt diffs to stop the noise. The Torsen does not require it to function properly, but it will NOT hurt anything to add it to try and tone down the noise (except for the $4.00 - $8.00 for the cost of the additive).