JHZR2
Staff member
Originally Posted by Spddm0n
I've also run into murky waters, dealing with LSD additives. All the vehicles have LSD, some with break-away-torque figures that vary wildly, so I'm trying to find answers to concentration levels of LSD additives in each product. I was hoping to either use an oil with NO modifier in it and add my own, or find a conventional oil that has *some* additive in it (marketed as appropriate for LSD differentials) and try that on the majority of the vehicles, and add more additive if there is still chatter on some of the more aggressive LSD's in some vehicles.
I became super confused when Valvoline told me they add 4 oz of additive to each quart of 80W-90 synthetic gear oil, when the average bottle of additive sold separately suggests 4 oz per 2-quart axle (add more if larger than 2 quart axles). I was also told my the Napa guys that most of their customers complained they still had chatter when using the full synthetic gear oil (supposedly with 4 oz modifier in each quart) so they are all adding more, even to the synthetic. Having said that, Napa guys didn't know the conventional oil "used" to have LSD additives in it, until a year ago, and then Valvoline just removed the additives and didn't tell anyone - and continued using the same part number and removed the "Limited Slip" from the bottle. Ugh!
I wonder if WPP would comment on the amount of LSD additives (oz per quart) in their ST synthetic 75W-90? That might help me understand where to go from here. That viscosity looks like it should work in my applications. I don't have any idea what the kinematic viscosity was in the OEM 75W-85 from Nissan.
I thought I had read on here over a decade ago that the lsd additive actually somehow hardens or otherwise favorably affects the metal surfaces so it's not a bad thing to have in there at a "heavy" dose. Not sure how much of an effect too much has when the torque settings are set at different levels though...
I've also run into murky waters, dealing with LSD additives. All the vehicles have LSD, some with break-away-torque figures that vary wildly, so I'm trying to find answers to concentration levels of LSD additives in each product. I was hoping to either use an oil with NO modifier in it and add my own, or find a conventional oil that has *some* additive in it (marketed as appropriate for LSD differentials) and try that on the majority of the vehicles, and add more additive if there is still chatter on some of the more aggressive LSD's in some vehicles.
I became super confused when Valvoline told me they add 4 oz of additive to each quart of 80W-90 synthetic gear oil, when the average bottle of additive sold separately suggests 4 oz per 2-quart axle (add more if larger than 2 quart axles). I was also told my the Napa guys that most of their customers complained they still had chatter when using the full synthetic gear oil (supposedly with 4 oz modifier in each quart) so they are all adding more, even to the synthetic. Having said that, Napa guys didn't know the conventional oil "used" to have LSD additives in it, until a year ago, and then Valvoline just removed the additives and didn't tell anyone - and continued using the same part number and removed the "Limited Slip" from the bottle. Ugh!
I wonder if WPP would comment on the amount of LSD additives (oz per quart) in their ST synthetic 75W-90? That might help me understand where to go from here. That viscosity looks like it should work in my applications. I don't have any idea what the kinematic viscosity was in the OEM 75W-85 from Nissan.
I thought I had read on here over a decade ago that the lsd additive actually somehow hardens or otherwise favorably affects the metal surfaces so it's not a bad thing to have in there at a "heavy" dose. Not sure how much of an effect too much has when the torque settings are set at different levels though...
![[Linked Image]](https://www.bobistheoilguy.com/forums/attachments/usergals/2019/10/full-82287-37196-lubegard_lsd_additive_effect.jpg "[Linked Image]")
