AmsOil Severe Gear 75W90 rear diff issue
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Added the additive, and all noises went away.
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From: Austin, TX
No, I got bad news for you. I thought the same, It said in the bottle the oil had the LSD additive, and the chattering was there everytime I turned. Called the differential builder, and he told me to add the additive, and to never trust those labels.
Added the additive, and all noises went away.
Added the additive, and all noises went away.
I heard that GM additive can't be use with this AMSOIL fluid.
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From: moraga ca
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From: King George VA
Corvetero,
Sorry missed this chain.
The Severe Gear 75w90 is recommended by AMSOIL for your 92 and as you indicate, it does have limited slip additive already in it.
Many GM diffs are prone to diff whine, which is a distinctly different problem than diff chatter. Based on my observation of this issue over the years, no diff fluid can fix diff whine, and that assumes you really do have diff whine.
I personally wouldn't spend money replacing it with anything else. FYI, this is the same fluid I use in my 02 Z06 at the track.
Sorry missed this chain.
The Severe Gear 75w90 is recommended by AMSOIL for your 92 and as you indicate, it does have limited slip additive already in it.
Many GM diffs are prone to diff whine, which is a distinctly different problem than diff chatter. Based on my observation of this issue over the years, no diff fluid can fix diff whine, and that assumes you really do have diff whine.
I personally wouldn't spend money replacing it with anything else. FYI, this is the same fluid I use in my 02 Z06 at the track.
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C66 Racing #66 NASA ST2, SCCA T2
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AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)
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From: King George VA
No, I got bad news for you. I thought the same, It said in the bottle the oil had the LSD additive, and the chattering was there everytime I turned. Called the differential builder, and he told me to add the additive, and to never trust those labels.
Added the additive, and all noises went away.
Added the additive, and all noises went away.
The AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT) does have limited slip additive in it. That said, not all diff's need the same amount of additive to prevent diff chatter. In the C6 diff, GM increased the diff clutch plate pressure (by a lot) and C6 diff's need much more additive than C5 and prior diffs. What I learned last year (as it happened to me), in many cases when a diff is worked on, instead of the original diff clutch plates, newer ones may be used. Thus it is really hard to tell what is in the diff.
In general, if the diff does chatter (as opposed to whine), then adding extra additive will correct the chatter. The AMSOIL Slip-Lock Differential Additive (Product Code ADATB) comes with a long snout on the tube and in most diffs, opening the fill tube and squirting in a few ounces of the additive is pretty easy.
P.S. For the OP, I can't ship to Spain or I'd offer to send you some Slip Lock to try it, sorry.
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From: Austin, TX
Both sides of this discussion are correct, but the issues are complicated.
The AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT) does have limited slip additive in it. That said, not all diff's need the same amount of additive to prevent diff chatter. In the C6 diff, GM increased the diff clutch plate pressure (by a lot) and C6 diff's need much more additive than C5 and prior diffs. What I learned last year (as it happened to me), in many cases when a diff is worked on, instead of the original diff clutch plates, newer ones may be used. Thus it is really hard to tell what is in the diff.
In general, if the diff does chatter (as opposed to whine), then adding extra additive will correct the chatter. The AMSOIL Slip-Lock Differential Additive (Product Code ADATB) comes with a long snout on the tube and in most diffs, opening the fill tube and squirting in a few ounces of the additive is pretty easy.
P.S. For the OP, I can't ship to Spain or I'd offer to send you some Slip Lock to try it, sorry.
The AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT) does have limited slip additive in it. That said, not all diff's need the same amount of additive to prevent diff chatter. In the C6 diff, GM increased the diff clutch plate pressure (by a lot) and C6 diff's need much more additive than C5 and prior diffs. What I learned last year (as it happened to me), in many cases when a diff is worked on, instead of the original diff clutch plates, newer ones may be used. Thus it is really hard to tell what is in the diff.
In general, if the diff does chatter (as opposed to whine), then adding extra additive will correct the chatter. The AMSOIL Slip-Lock Differential Additive (Product Code ADATB) comes with a long snout on the tube and in most diffs, opening the fill tube and squirting in a few ounces of the additive is pretty easy.
P.S. For the OP, I can't ship to Spain or I'd offer to send you some Slip Lock to try it, sorry.
On 5th and 6th gear the whine is louder under this condition.
Actually, I'm wondering if the noise might be coming from the tranny in lieu of the diff. BTW, also fresh AMSOIL 5W30 MTF
Last edited by corvetero; Sep 23, 2014 at 04:54 PM.
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From: King George VA
Thank you very much C66 Racing. As you posted, it's like the diff whine when you are driving at low revs and just applying minimum force on the throttle pedal. As soon as you push hardly and revs going up it's like no noise.
On 5th and 6th gear the whine is louder under this condition.
Actually, I'm wondering if the noise might be coming from the tranny in lieu of the diff. BTW, also fresh AMSOIL 5W30 MTF
On 5th and 6th gear the whine is louder under this condition.
Actually, I'm wondering if the noise might be coming from the tranny in lieu of the diff. BTW, also fresh AMSOIL 5W30 MTF
