Redline (with lsd additive already in it) in rear differential. LSD additive still needed?

[NETim]

I am about to change the rear differential fluid in the truck and use Redline 75W-140. It is supposed to have the lsd additive already in it.

Will I still need to add lsd additive as well? I've done searches here and haven't really been able to come to any solid conclusion. Is this kind of a trial and error thing?

I have about 90K on it and to my knowledge, the rear diffy fluid's never been changed.

Thanks!

 

[danielmid]

Probably won't need it but grab a bottle anyways, change the fluid, then go do some slow turns and listen to see if you need to add it.

 

[MRFREEZE57]

I used that in my LSD rear end, did not add any additive and has been working fine for 20k miles.

 

[crash68]

Same here, used the RedLine 75W-140 and didn't need to add any friction modifier for the 1500 OEM LSD.
Red Line also makes a 75W140NS that does not have the friction modifiers already added

 

[Badger 13]

I'm with the previous posts, changed to Redline 75W-140. I have some Mopar friction modifier if it was needed, but it was just fine w/o it.

 

[pacofortacos]

Not needed in my experience with Redline and my factory LSD.