If adding one bottle of the limited slip additive is recommended; would adding more than one bottle be Better, a Problem, or No difference?

 

No, you want to add the minimum amount required by the diff. In some cases this may actually be less than one bottle. Or if you used synthetic gear lube (Mobil 1, Redline, etc), then you may not need any at all as they already come with an LSD additive.

 

Thank you. The reason I asked is, last night I changed the differential fluids in my Z28. As you know there is not much space to add the fluids and teh LSD bottle that GM uses does leak so I am sure not all the LSD additive went in the readend. I did use Mobil 1 and that makes me feel better. Thanks again.