So after two more autox events and some really hard driving my rear diff is starting to make noise sporadically while cruising. This is getting annoying. Is this happening to anyone else? What are the noises like that everyone else is hearing after the reassembly?

 

Cruising in a straight line or during tight, low-speed turns?

 

mine is making noises everywhere now, turning and in straight lines.

 

in straights? what kind of fluid are you using? vid of noise?

 

No noises here. It's working pretty well and I'm adapting to it.

 

I am using amsoil but I don't have a video.

 

75w90 svgear? Try diaqueen. I'm rocking amsoil but i dont mind the noises. my diff flat out BANGs in turns at low speed, but never in straights

 

I don't think Diaqueen is going to do anything. I just ordered redline friction modifier and hopefully that helps.

 

the rear diff actualy calls for straigh 90w oil, which is what diaqueen is. Lubricates better than other stuff, doesnt have all the other additives and crap.. this is according to jon@tre btw

 

If that was so then the noise wouldn't be apparent in the first place and mitsubishi wouldn't of installed the plates the way they did because of customer complaints.

 

Redline 80301? My diff makes chattering sounds at low corners. No sounds driving in a straight line

 

Actually, this is straight from TRE's FAQ on rear diff oil reccomendations on their webpage. He actually reccomends the Redline gear oil (NS is what I run) or even the heavy shockproof for drag racers.

96-07 EVO: Mitsubishi recommends that the rear axle that is found in the EVOLUTION be filled with their factory oil, Diaqueen LSD Gear Oil part# 3775610 or a high quality GL-5 or higher 90w Hypoid LSD gear oil. These oils contain a friction modifier that will reduce noise associated with friction disc type limited slips.
REDLINE 80W-140 GL-5 GEAR OIL We highly recommend using Redline 80W140 GL-5 Gear Oil. Their part number is # 58104. For road racing applications, use Redline 80w-140.
* If you are wanting to increase the lock-up of the limited slip differential you will want to use Redline 80w-140 NS. This oil will increase lock-up but it does not contain the friction modifiers that reduce noise.
REDLINE SHOCKPROOF HEAVY If the vehicle is going to be drag raced Redline Shockproof Heavy is an excellent oil for the rear axle but outside temps should be 45*F or warmer because the oil is not thin enough for cold weather use.

 

Amsoil is a GL-5 gear oil and has been used in track cars. I don't road race my car nor drag it but the car does get launched 6-10 times per autox event twice a month. The car was quiet the first three events and then after the fourth the noise started to become apparent but wasn't until after the sixth that it can now be heard by people driving behind me and during straight line driving. So basically my biggest concern here is the straight line noise as I seem to be the only one who this does it to. I would hate to have to take my diff apart again after I thought I followed everything during the install perfectly to spec.

 

You shouldn't be having any noises in straight line driving. The noises are caused by the friction plates slipping against each other due to differential wheel speed when the diff is working as it should. And you should only have differential wheel speed in a turn.

With no rear interior, polyU bushings, etc,etc and NS fluid mine is crazy loud poking around the paddock when I turn, but makes no noise in a straight line.

Post up a vid if you can. The noise in slow turns is a popping almost percussive deal.

 

With the diff fully supported with urethane bushings I get a whine if slightly decelerating on the freeway. Also I get a touch of chatter if I take off when cold in a tight radius.