The 510 Realm

okayfine wrote:The type of diff in the STI varies with market and year.

His stuff is JDM, which may or may not match what Qwik510 posted. USDM got those years of STi, and much was changed for the different market.

Why the about the Torsen, that's the preferred LSD generally, unless your drag racing or maybe ice racing, or what do I know?

I checked out an "R180" today for sale.
There is no I.D. placard. How can I determine it's a true R180
I tried looking up the numbers but can't find any information..

As opposed to what? An R180 is physically larger than an R160, and an R200 is bigger still. The R200 is easy to tell apart with lack of scale because it's visibly more "round" looking at the rear cover. Between the R160 and the R180 it's hard to tell in pictures, but the top two bolts on the cover of an R160 are noticeably closer together than the rear subframe mounts on the cover, whereas the R180 top two bolts on the cover are practically the same distance apart as the subframe mounts on the cover. Hard to tell in your pics because you have it lying upside down, but it appears to be an R180 and probably has a big 'K' stamped on the top.

That is a R180 because this was the only diff to have a temp sensor in it. As thisismatt said there should be a big K in the casting on the top.

If you want to know what the ratio is then ask for a axle and place it in the side. Make a mark on the input shaft and on the axle. Then start spinning the input shaft. It most likely is a 3.54 or a 3.90. If you don't have a axle then you can unbolt the diff cover off and take a look at the Ring and Pinon and it will give a spline count stamp on it. Don't worry about sealent on the diff cover as it is a metal reusable gasket.

Hope this helps.

angzt wrote:How can I determine it's a true R180

Are you asking if it's an R180 or an LSD? Pop the cover to see if it has the LSD center section.

okayfine wrote: LSD? Pop the cover to see if it has the LSD center section.

first check if the axles rotate the same direction.
if its an open, theyll spin opposite. (unless its welded )

hang_510 wrote:

okayfine wrote: LSD? Pop the cover to see if it has the LSD center section.

first check if the axles rotate the same direction.
if its an open, theyll spin opposite. (unless its welded )

Don't forget to have sopme one hold the input shaft when you spin the axel

Stopped by and looked at the diff again. It does indeed have a "K" in the casting. I never knew about the K, you learn something new every day. Both axles do spin the same direction, LSD!

The guy swore on his life that he just recently pulled it from a 2005 STi with 50k miles.

Long story short, I paid $350 for it

I also have in my possession the previous posted halfshaft's being sold on the hybridZ forums.
...and I should be receiving my Wolf Creek CV setup soon.


Anybody have any experience with the Perrin diff cover? Those cooling fins look like they might not fit underneath..