Developed a vibration in the rear at the last track day. On the drive home, rear end has a low whirrrrrrr (roll that "r") under any sort of throttle application that's very noticeable once above 50mph.

Tried adding in some axle spacers, no change (haven't swapped cups yet). But, I did just drain my diff fluid and found this.

Fluid was very very thick.


shards and lots of metal on diff plug


Is it OS Giken time? This is on the stock torsen diff. Has around 100 track days on it.

 

Ugh! Good luck with the fix!

 

You haven't told us about your differential maintenance and oil change schedule and what oil you use(d) in there. Last differential oil change was when and how did the oil look? 18 year old OEM differential got you thru 100 track days with unknown maintenance. Another OEM differential should be just as good and will "drop right in."

-- Chuck

 

This. Replace every 6-8 track days.

This last interval was 6 track days. Oil doesn't normally look like this and didn't have metal shards on the drain plug.

Not looking at another OEM unit. I'm running full aero with 18x10.5 wheels with 265 cheater 200TW tires.

 

Well, I can link to the sound mine made RIGHT before it died (it fails at the end of the vid). Now, sound is not great here since Catalyst only exports vids of full laps, and since I never completed the lap I had to literally record the screen from my phone Note when I lift you can start hearing the noise. May not help you much here as the sound quality is not great but figured I would try to share. At first since I was catching the vette I thought the noise was coming from his car, and then found it was not Now, for me, no crazy noise I could find in any video up to this point so once I heard it, it was already about to let go. After tearing it down I think this was a case of the crush sleeve issue causing the pinion depth to change and thus killing the diff. I had a spare OEM and tossed it in. But I think going with a puddymod built diff with OS Giken would be my choice if spending more money to fix it. I think the general approach is getting/setting up the OSG through Jonathan Lugod, then having Puddymod do the diff reinforcement and install of the OSG. I know his lead time has been crazy at times though.

 

Yup. I can hear the same less pronounced whirrring noise from my rear. No noise on mine off throttle though.

 

Worst part is that I was thinking ... "what the hell is that noise from the vette?" then "oh crap that is my ..." BRRRRRRRRRRRRRRRRRRRRR! lol. With all the other noises, plus helmet, it took a bit to realize what was happening.

 

It does look like you need a diff, unfortunately.

At least the OSG is gonna be sick

 

Driving Ambition here in Rancho Cordova has built on the OEM diff and builds them new and improved with 3D CAD and maybe some printing. The Honda Dealership in my area mentions them for any S2000 that needs a diff. All they do is race nationally with S2000 and NSXs. I have been there several times and it is quite a shop. They formed from Comptech building superchargers that were warranted by Honda for the S2000.

If I were you, I would contact them and see what they say.


https://drivingambitionmotorsports.com

 

He probably just needs a diff which is less likely to break when driving across curbing.

I think the OSG will help there