Severe gear 75-90?
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Instructor
Joined: Oct 2014
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From: Illinois
Severe gear 75-90?
I read a lot of you are using the 75-90 weight synth rear Amsoil fluid, my question before I do this is…what is the stock gm weight? 80-90? If so why not use the 80-90 synth Amsoil?
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From: King George VA
AMSOIL's best gear lube doesn't come in a 80w90, only 75w90. Been using this at the track for about 10 years now and haven't lost a diff yet (though I have rebuilt it a few times and finally replaced it last year after 10 years of racing):
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
Note: This fluid comes with friction modifier already in it and extra additive isn't normally needed in the C5 to prevent diff chatter.
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AMSOIL Dealer (Forum Vendor)
AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)
Thread Starter
Instructor
Joined: Oct 2014
Posts: 143
Likes: 0
From: Illinois
The stock spec was synthetic 75w90.
AMSOIL's best gear lube doesn't come in a 80w90, only 75w90. Been using this at the track for about 10 years now and haven't lost a diff yet (though I have rebuilt it a few times and finally replaced it last year after 10 years of racing):
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
Note: This fluid comes with friction modifier already in it and extra additive isn't normally needed in the C5 to prevent diff chatter.
AMSOIL's best gear lube doesn't come in a 80w90, only 75w90. Been using this at the track for about 10 years now and haven't lost a diff yet (though I have rebuilt it a few times and finally replaced it last year after 10 years of racing):
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)
Note: This fluid comes with friction modifier already in it and extra additive isn't normally needed in the C5 to prevent diff chatter.
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you only need 2qts and you will have a small amount left over... guess your next diff fluid change will be 1/2 price
... I've used amsoil fluids in the trans and diff since I've owned my car and it has been great
... I've used amsoil fluids in the trans and diff since I've owned my car and it has been great
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Burning Brakes
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Thread Starter
Instructor
Joined: Oct 2014
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From: Illinois
Well that's a waste of $15 I guess on my end :/ also I heard I wouldn't need the additive? Now I do? I didn't buy any should I pick some up?
Burning Brakes
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Intermediate
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I just added severe gear in the rear without the additive and haven't had any issues. The torque drive atf in the transmission was a relevation. Shifts are smooth with no balking. I just today installed a C6 shifter, taking the shifting to the next level!
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Instructor
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From: Illinois
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no additive needed, as stated above the fluid has its own addidive... I've changed mine a few times over 4 years with strictly amsoil gear oil (no extra additive) and haven't had any issues
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From: King George VA
Note that isn't the case for the C6/C6 Z06 which do require a lot more additive than the C5/C5 Z06 diff as GM increased the diff plate pressure on the C6. For C6 owner's I do recommend more additive than is in the Severe Gear. And yes, the C6 Z06 diff does require 3 qts but the C5 Z06 will come in at about 1.6 qts or so.
Thread Starter
Instructor
Joined: Oct 2014
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From: Illinois
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From: King George VA
Instructor
Joined: Dec 2012
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From: Charleston South Carolina
Yep..>Severe Gear is way to go...been Amsoil dealer and using their products in everything from 3 Indian motorcycles, Land Cruisers (84, 2000, 2008), BMW 335i and now my Vette. Never a problem.....great product in spite of some naysayers.
Melting Slicks
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