Sgt Pyle,
As Denny mentioned, Redline puts out two different types of 75w90, one with the friction modifier pre-mixed in, and one without. Looks like you have the 75w90 which already has friction modifier in it.
Here is what Redline says about adding too much friction modifier: "Limited slip or positraction units will often chatter without use of this product or a gear oil with a similar modifier, so add only enough to eliminate the chatter and avoid making the plates or clutches too slippery. "
Here is what AMSOIL says about friction modifiers in their 75w90 (which also already has friction modifier in it): "If limited slip differential chatter occurs, add
AMSOIL Slip-Lock Differential Additive."
At my first few DEs, I used Redline 75w90 and did not add any friction modifier and my diff did not chatter so I didn't add any friction modifier. At the start of the 2004 seasib, I switched to
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90, which also has the friction modifier in it, and again my diff didn't chatter so I didn't add any extra friction modifier.
My suggestion to you is to try the Redline 75w90 without the friction modifier. If your diff chatters, then add half a bottle of the friction modifier. If it still chatters, add the rest.
Note: The diff takes just under two quarts of gear lube (1.69 quart according to the service manual).
Note: The service manual does state not to operate at WOT for 300 miles after refilling differential with lubricant and friction modifier. Scoring of the ring and pinion gears may result, leading to differential noise.
. I have a few quick questions I hope someone can help me out with. I plan on useing RedLine 75W-90 but how many quarts do I need and will I need the GM Limited-Slip Addative? Thanks in advance!
Linear Mode
