Limited slip additive or not?

[Rocket Man]

Interesting, we used the factory additive in our 1980s Buicks and none of us ever had to rebuild our differentials until RWHP exceeded 550. We laid down miles and miles of twin stripes of black too! If I remember right, 2 or 2 1/2 of those little bottles did the trick and no chatter. Our G80s were 8.5" 10-Bolts and did not have the locking feature, just limited slip.

Maybe that’s because, as I understand it, the synthetic oils spec’d for it ( Mobil 1, Royal Purple,etc) already either have the additive or else they have properties that mimic it. It would seem that adding more would double the amount of slipperiness the additive was designed to do.

 

[swathdiver]

Maybe that’s because, as I understand it, the synthetic oils spec’d for it ( Mobil 1, Royal Purple,etc) already either have the additive or else they have properties that mimic it. It would seem that adding more would double the amount of slipperiness the additive was designed to do.

No Mark, I was responding to Aaron's post about our historical use of the LS additive. Back then the factory gear lube was not synthetic and did not contain the LS additive. You're correct, Mobil One and Royal Purple do include the additive these days so it is not needed and too much might be worse than not enough.

 

[asand]

This was a 454 Muncie M22 car. I imagine the torque, shock load, and racing slicks were just too much for the clutches.

 

[swathdiver]

This was a 454 Muncie M22 car. I imagine the torque, shock load, and racing slicks were just too much for the clutches.

It was fun rowing gears with those Rock Crushers!

 

[asand]

@swathdiver Ive never driven one myself, but my dad put one in his nova after I left Kalifornia. The 5.00:1 gears didnt like the shock loading nuch.

 

[swathdiver]

Ive never driven one myself,

Mine was behind an LT-1 in a '70 Z-28 Split Bumper Camaro. The M22 has close ratios suited well for road racing. That Nova I'm sure was a hoot to drive!

 

[afpj]

My wife would love to drop the kids off and pickup from school in that Nova...show a thing or two to those snooty BMW and MB Moms!. A different type of awe from the Uncle Buck mobile.

 

[Jolly Roger]

So,...did we ever decide whether or not to use an additive on a G80? My shop just added it to my G80 rear along with DELVAC 1 75/90. Did they mess up?

 

[Bob2C]

I went with AMSOIL Signature 75w-90 with NO additive in my 18 max tow package. No chatter/noise. Very smooth.


Sent from my iPhone using Tapatalk

 

[wjburken]

So,...did we ever decide whether or not to use an additive on a G80? My shop just added it to my G80 rear along with DELVAC 1 75/90. Did they mess up?

The manual for your 2007 Tahoe does not call for additive, just 75W-90 synthetic gear oil. GM 12378261 has been superseded by AC Delco 10-4016 if I’m not mistaken which has no additives.