Just got out from a quick spin after changing my diff oil from Mobil 1 to Motul 90PA and all I can say is WOW, what a difference it made. My differential is the Cusco RS lsd, setup as 1.5-way at 80% lock. I have driving it daily like this for about 25k miles and always using Mobil 1. It has always been a burden, popping like crazy in low speed corners and always being able to tell when it goes from engaged to disengaged, but I was able to live with it, until about a week ago it just started to really **** me off.

The Motul stuff is awesome. There is still a little inside wheel locking at parking lot speeds, but at least 10x better than what it used to be. Driving around it isn't even noticable when going from lock to unlocked...just awesome. So please, if you have a loud, harsh diff..do yourself a favor and get some of this oil.

 

how much is a bottle and how many bottles would i need?

where can I get them on the net?

 

Glad to see others having the same experience I had with it on my Nismo diff..

 

How often (miles or time) are you guys changing the differential fluid?

 

I'm planing on doing mine every 30k miles, but seems lots of members change it more often.

 

Stock diff changes for daily driven cars at 30K are fine.

Tracking driven, and clutch style LSD's need much more frequent changes...usualy in the 5-10K mile range.

 

I just ordered some fluids for a change from you Sharif. I was waiting 12k-15k miles but I'll knock it out now at 6k just to be safe.

 

my local tuner shop started carrying this. So it's ok to use this 90pa for the stock viscous lsd? Two bottles?

 

Stock viscous, use 2 bottles of motul Gear 300

 

Just put the Motul products in the Nismo rear and tranny and I have to say its like driving a different car. I wont get into details cause I dont like to make speeches to others. But If anybody has or buys a Nismo LSD or one that is similar to it The Motul 90PA is the only thing that should be touching the gears. 96% of the noise is gone.

 

Do you think it is necessary for the stock VLSD or would it make no difference since it is silent as is. Also, when you say 2 bottles you are talkin about quarts right? The owner's manual says the stock VLSD uses 1.4 liters or 3 pints so wouldn't 2 be a little too much?

 

I also used the motul oil in my diff, also got cusco rs 1.5way, but set at 60% lock.

yes it does make it go smooth but what I found after a while is that its locking is not as strong anymore. If I put my car up and turn one wheel while holding the other wheel, its only giving minor lock. before it was very tough to turn one wheel while holding the other, but now I can do it just by holding one hand onto one side while turning the other side with the other hand.

I wonder if the clutch disc has already worn out or its just the oil that has too much friction modifier which makes it slip too much.

at the next interval i am going to take the diff out and set it at 80% lock.

 

Read two posts up:

 

My bottle was 2L and I had about 1/4 of the bottle left over so yes you will to if you buy 2 1L bottles. But I had the mechanic use the Motul fluid (after draining old fluid) to flush out the reamaining black fluid that was in the differential. So extra is a good thing IMO. I recommend you have extra for this step cause even if a little of the old fluid stays in I think its defeating the purpose of changing the fluid.