Looking for some information on what type of rear diff i have in my 2002 STi, did a oil change on both gearbox and rear diff last September, used Millers CRX 75/90NT oil and is good in the box but I have issue with the rear diff locking when hot at low speeds tight turns.
From reading on here and posting on other threads I have bought some Millers CRX LS 89/90 NT for the rear diff, the thinking behind this that the rear LSD does not like the normal oil?
Also found that the diff LSD is a sealed unit with its own silicone based oil within the diff and is not come in contact with the main oil, so will LS oil make any difference?
Also read that the front has LSD and should different oil be used in the box?

 

You can not use LS oil in syncromesh gearboxes. I don't think the front diff is limited slip, i would of thought that would make steering the car very difficult.

 

The gearbox is fine and its the rear diff in question.
Not planning on changing the oil in the gearbox only the rear diff.
Hence the question on the LS oil.

 

So should I put in the LS oil or keep the normal 75/90 oil???

 

Opie oils might be able to help you.

 

That the issue I was advised to us the CRX 75/90 in both the gearbox and rear diff then from reading other posts it looks that the 80/90 LS NT may be required.
As in my first post the LSD is sealed unit and the use of LS oil may not be required.

 

I also bough CRX75w90NT for my gearebox and diffs (inc rear) because that was advised on opie oils site. I started a thread to ask the question you are asking and the advice given by AS performance and many other on their experiance was, use a Limited slip diff opil. The millers oil would be CRX LS 80w 90 or CRX LS 75w or 80w 90 NT. Nt just being Nano technology so a tad more expensive.

 

Understand what you are saying, I current have CRX 75/90 in both the box and rear diff from advice from oipe, but from more research it seems unclear what to put in the rear as the LSD has it own sealed silicone bath which does not come into contact with the main oil of the diff so LSD oil would not make much difference???
Also posted on your thread along with others on other forums and there are many interpretations of what to use, I have the CRX LS 80/90 NT and plan to put this in tomorrow and see what happens.

 

i don't know the inner workings of our rear diff and your silicone oiled sealed unit is something i've not hear before. Obviously very interested like you to be educated on this matter.

 

Read post no 4.

http://forums.nasioc.com/forums/show....php?t=2239546

 

Just says its a Hk, hypoid gear. I don't really know what that is let alone know its some seal unit? Did i miss something in that post ?

 

Or this item no 19 gives part numbers and with call to dealer may help.

http://opposedforces.com/parts/impre...llustration_2/

 

Sorry mate. blame it on a saturday night of drinking but i am missing your point. I cant see where that shows the LSD is a sealed unit ??

 

Sorry that is for the front, this one is for the rear and shows what year of use.
Now going to google the part number.

http://opposedforces.com/parts/impre...al_individual/