Gear oil
Thread Starter
Instructor
Joined: Jan 2006
Posts: 160
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Gear oil
A friend of mine says he has ran 85w-140 lucas gear oil in his 6 speed vette,says no limited slip additive needed,just wanted to here your opinion on this,he also says the thicker oil will make the gears less noisy. Thanks
Tech Contributor
Joined: May 2008
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From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
The heavier oil may help to reduce gear noise, but it will cost you a few horsepower and some reduction in gas mileage too. It takes more power to make the gears to churn through heavier weight gear oil.
Safety Car
Joined: Nov 2000
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From: Shenandoah Valley Virginia
Use the factory recommended 75-90 weight oil. GM designed it and knows what is proper for the application. Use a good quality full synthetic like M-1 or Redline. No need to add the modifier with either of these, it will be smooth and quiet.
Premium Supporting Vendor
Joined: Aug 2001
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From: King George VA
I'd just use a good synthetic 75w90 as originally recommended by GM. Here's what I've been using at the track since 04 - no failures. This fluid does have friction modifier already in it and extra is not needed to prevent diff chatter in the C5/C5 Z06:
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
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From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
ANY time someone is using a heavier gear oil to make gears "less noisy", indicates a problem far greater than they are willing to admit.
Maybe they would also "recommend" using a high viscosity motor oil in the engine to "quiet" those pesky rod bearing knocks too.
Maybe they would also "recommend" using a high viscosity motor oil in the engine to "quiet" those pesky rod bearing knocks too.
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Tech Contributor
Joined: May 2008
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From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
Melting Slicks
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From: Oceanside California
Melting Slicks
Joined: Jun 2010
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From: Yorktown Virginia
I know someone who added some gear oil to their engine to bump their oil pressure up whenever the rods started knocking, they said that they ran it like that for 50k or so...