I've been running redline lightweight shockproof in my rear diff, and I swapped it for fresh fluid last night. First, the fluid I drained looked and felt new. So it holds up great even with the abuse I subject it to at the track. Second, no metal flakes collected by either magnetic plug. So I'm very pleased

Next, I swapped my OEM tranny fluid with redline MTL 75w80 fluid. I took it for a couple mile drive after for various reasons and the difference in shifting feel is significant. Much smoother. I'll put it to the real test next week when I do the next Watkins Glen event and I'll post back with further thoughts

 

Assuming you also added the friction modifier?

 

Did the same to mine a few weeks ago. The car feels so much better!

 

I changed out to redline at 4k on the clock and nver looked back. Shifts very good. Not sure when to change it the next time though. Redline in my dd differential works just fine also.

 

Nope, not for my torsen

 

I switched to MTL a year or two ago and it made a noticeable difference in shifting. I was running Royal Purple 75w 140 in the rear diff since it was available locally. I changed the fluid last week and switched to Redline since I was so happy with the transmission lube even though I had to order it in. I haven't been running it long enough yet to know how it is going to hold up.