I have a JDM EVO 1 and whenever I do a sharp turn in reverse or moving forward with very slow exceleration when pulling off from a stand still, I get a knocking/"cluncking" sound (almost like bad CV joints) in the front section of my car. Once I get going, I don't hear it anymore and the car drives fine. If I pull off from a stand still the same way, but without turning the wheel in any direction, I don't hear anything at all and I was told that it was because my car has a cusco differential in it and they are known for that. The CV joints were replaced anyways just to be safe and still the same thing...Is there any truth to this? I have a lot of people behind me wanting to buy this diff off of me (if I can't deal with the sound) as they want it to use for racing at the tracks to get better numbers, but I'm not too sure if I want to give up a part that supposedly retails for about $1700 just for a slight knocking sound when the car performs and drives as well as it does despite the occasional noise. Anyone ever heard anything like this before...

 

yes- they do make a small amount of noise

yes- you should keep it. Replacing the Cusco with an original Evo 1 diff is not as simple as you would think. There are two types diff (open and viscous lsd) that came with the Evo 1 and they arent interchangable.

It is very likely that your car came with an open diff and that was replaced with the cusco diff that fitted- that means you will need to replace the Cusco with an open diff.
The viscous LSDs arent very good, so even though they are quiter you will be better off with the noise.

 

hmmm I didnt know cusco mada a detroit locker diff lol, sounds like the noise they make

 

Welcome to the world of locking lsd's lol. I use to drive with the nismo one's in 350z, and G35's and it would always do that. Price you pay.

 

Thanks so much for the replies...I feel a lot better know knowing that that's what it was for sure. I'm definately going to keep it... I can deal with the noise(LOL).
Thanks again...

 

I had another small question concerning this diff...Is there any specdial type of gear oil I should be using? I've noticed the diff is a little more noisey now and going from a turning reverse (where I usually hear the noise) and I try to put it back into first gear, sometimes it feels like the gear is blocked and I can't get it into first. I found a sort of sweet spot where I can get it into first now when this happens, but I'm thinking I need to replace the gear oil because I'm not sure when last it was changed, so I was just curious on opinions on which I should use...