: changing diff oil

09-12-13, 11:15 AM
I've developed a major whine after my revshift bushings. Want to change the diff oil since I'm not sure if the previous did or not. He did tell me it has the latest generation diff but I'm mot sure howmany miles he put on the car with it. Car has 69k miles.

Anyway, I'd like to know what I should get..

So far I'm getting 2x quarts of amsoil 75w-90. My real question is, do I need limited slip addictive? If so, which one should I get? How many oz?

Any help would be much appreciated.

09-12-13, 11:22 AM
Unlikely you developed the whine after the mount. Possibly more noticeable, but I just put a red one in myself (replacing a pretty decent OEM) and noticed absolutely zero increase in noise.

What sort of shape was your old bushing in?

I'd read that heavier weight oil would help with the noise (mine had the 40-50mph whine), so I used 1qt of 85-140 GL5 from the FLAPS along with a 4oz bottle of additive. I topped up with 90W that was already on hand.

09-12-13, 12:34 PM
sorry I meant to say it increased the noise, it was always there but hardly noticable. Now I get the whine from 40mph and up,

I put the red craddle and diff bushing. My original ones weren't in horrible shape but I wanted the tighter feel.

09-12-13, 01:02 PM
That's odd; mine is pretty well gone. Very noticeable before under super light load 40-50mph. I now have a different, lower pitched, mechanical rumbling, but I can live with it.

Try the heavier oil and additive.

09-12-13, 01:59 PM
Amsoil says you don't need the additive, but I always get their 4 oz. bottle and add it.

09-12-13, 02:12 PM
Amsoil says you don't need the additive, but I always get their 4 oz. bottle and add it.


09-12-13, 02:53 PM
I'm using the amsoil as well. I didn't put any friction modifier in though. I haven't heard any groaning noises to say that i need to use any modifier.

09-12-13, 05:36 PM
If it is the Severe Gear, you probably don't need it on the V1 diff. Originally you didn't need it on the V2 diff, but eventually it did...

09-12-13, 06:07 PM
... I put the red craddle ...The Specter Werkes cradle bushings increased my diff whine ... noticeably.

09-12-13, 06:11 PM
Oops - didn't even see that part! All I did was the diff bushing.

And a correction to my above irrelevant posts in the interest of posterity- my diff noise is at least as bad as before, didn't notice until warming it up. Sucks, but such is the breed.

09-17-13, 01:24 PM
Redline doesn't need LSD modifier.

If you do add modifier, always put it in before the gear oil so that you ensure you get the whole bottle in there before all the gear oil takes up all the room