For those of you who have a whine coming from your diff, (I'm not not talking about a chainsaw whine!) try putting in Redline shockproof heavy formulation gear oil . (70W250) I filled my diff with it today and 90% of the whine I had is gone. There is still a very slight whine at around 45 MPH but the whine from 60-70MPH is completely gone.
I did some experimenting with diff oils in my Viper and had experience with this oil already.It is the quietest of all of them. I put in the Redline shockproof heavy in the Z when I changed to a T/A cover. Yes I added the additive.
You won't see heat from the Redline shockproof. In fact they garantee you will see lower temperatures.
Here's a quote from their website......
" ShockProofTM Gear Oil has a 40% lower coefficient of friction and 250% the load-carrying capacity compared to conventional gear oils, which means that metal- to-metal friction is greatly reduced. Temperature reductions between 25°F - 75°F are common in circle track, road racing, and off-road racing. Improved durability in high-performance use is the primary benefit of the Heavy ShockProofTM and along with the improved durability is an improvement in efficiency, but if further improvements in efficiency are desired, and durability is not a major concern, LightWeight and SuperLight ShockProof TM can be used."
if you want tom take it the whine out. get it reshimed. take out shiming and pull the gear back. it worked for me!! now my rearend is quite <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />