WRX's rear diff????

[jamesy]

hey guys, did anyone know that 2002 WRX rear differential (manual tranny, LSD equiped) could fit in my 92 SVX?

It seems to be same gear ratio, but not sure.

James

[alex_umn]

The WRX uses a so-called R160 differential, whereas the SVX (and STi) use an R180 rear differential. These units are not interchangable, but the ring and pinion gears from the E160 can be put in an R180 case; the R180 will not fit in the R160 case because the set is physically larger.

fwiw...

[NomadTW]

yeah but you wouldn't want to put an r160 in your svx it's not as strong
i had forgotten this fact that the svx and legacy use the r180 rear end and told my friend with an impreza with a blown rear that he could use a legacy rear diff and when he took it to the shop they told him it was too big, i felt like an ass

[mbtoloczko]

The USDM SVX and USDM WRX share the same diff ratio in the rear. The USDM SVX has an R160 LSD rear diff just like the WRX. The SVX in other markets has an R180 LSD rear diff with a 3.7 diff ratio.

[svxsubaru1]

why does the US always get the down graded cars, no r 180, and we got the worse trannie.

[alex_umn]

Nope, all SVX models come with an R180. I have a picture in my personal locker comparing the two types; the difference is subtle...

I have a 3.90 STI R180 rear differential installed right now, and that fit with a little coaxing, too. I have a pic of the SVX vs. STi R180 differentials in my locker somewhere.

So, it's only the tranny that is crappy for USDM :D

[Phast SVX]

Originally posted by alex_umn
Nope, all SVX models come with an R180. I have a picture in my personal locker comparing the two types; the difference is subtle...

I have a 3.90 STI R180 rear differential installed right now, and that fit with a little coaxing, too. I have a pic of the SVX vs. STi R180 differentials in my locker somewhere.

So, it's only the tranny that is crappy for USDM :D
where had you slipped off to when we were having all this contraversy....
i had thought we had the R180...
phil

[jamesy]

Thanks you guys!

So I can swap the WRX one but do not expect it strong enough for my SVX.

[mbtoloczko]

Originally posted by alex_umn
Nope, all SVX models come with an R180. I have a picture in my personal locker comparing the two types; the difference is subtle...


How about a picture showing the difference between SVX 180 and an R160. I`d be interested in seeing what`s different.

[Subafreak]

Now I'v been told that the R-180 came in just about every Subaru except some early L model Imprezza's. The R-160 rears have screw in carrier bearing caps like on the trannys and are suppost to be really cute. I'm not sure what that makes the STI rear if it's even bigger than the R-180 thow.:confused:

[svxsubaru1]

Is a 1 gen legacy rear diff a R180 because its in my car right now after I swapped the LSD unit onto it. For the 5spd swap iam doing.

[svxsubaru1]

how much stronger is the r180 than the r160?

[mbtoloczko]

Originally posted by alex_umn
Nope, all SVX models come with an R180. I have a picture in my personal locker comparing the two types; the difference is subtle...

I have a 3.90 STI R180 rear differential installed right now, and that fit with a little coaxing, too. I have a pic of the SVX vs. STi R180 differentials in my locker somewhere.

So, it's only the tranny that is crappy for USDM :D

I'm a bit confused by your statement about the SVX having an R180 rear diff. You say there are pictures in your locker comparing an SVX rear diff to an '04 WRX STi rear diff (definitely R180), and you say that it can be seen that the diffs are both R180s. I'm confused because I found some pics in the "3/26/03" folder inside the "Six Speed/Saint Louis" folder comparing the '04 WRX STi R180 rear diff to another diff, and in those pics, one diff is clearly an R180, and the other is clearly not an R180. The ring gear in the other diff is visibly smaller in diameter than the ring gear in the R180 diff. Is the other rear diff a USDM SVX unit? If so, then its not an R180.

[alex_umn]

You know, I'm beginning to think that the R180 designation is a guideline more than anything else. So, even if the rear diff in an SVX is slightly physically smaller than the STi one I have in there now, it (the stock SVX unit, that is) is still quite a bit larger than what came out of the 91 Legacy, where I got the old 4.11 gears for when my car was a five speed.

I wish I still had all of the parts for the 4.11 rear diff for comparison's sake...at any rate, right now I'm pretty sure that the stock WRX rear diff is the same R160 unit, except for ratio and limited-slip function, as the one used in that old Legacy, as well as other various Imprezas and Forresters.

I'll try to do some searching about this, but at this point I'm kinda busy at work, running on little sleep after seeing Return of the King waaay too late last night :o

[svxsubaru1]

The diff out of the 1 gen legacy had a idenitcl case, idenical, the gears looked the same to.

[mbtoloczko]

the 160 in R160 is the diameter of the ring gear in mm, so it would be interesting if you measured the diameter of the SVX rear diff ring gear and that of the one in the other rear diff that you have. If you could snap a comparative pic of the SVX diff internals and the internals of the other diff, that would be cool too.

[Phast SVX]

i have one in my garage, ill try to get to it tommorow
phil

[alex_umn]

Would anyone have the ring gear out of the case right now? Otherwise it might be hard to measure what with the clutch packs (I think) in the center of the ring...

I'll take a look tomorrow, too I guess...

[oppositelock]

Wow, there's a whole lot of bad information in this thread!

Let me get you guys sorted out. Here's the easiest way to tell the difference between the R160 and the R180 is to measure the distance between the upper two and/or lower two bolts on the aluminum cover. On the R160 the two bolts are about 2 3/8" apart and on the R180 they are about 3 1/4" apart. The R180 is wider but not really taller. Also the plastic vent on the top of the cover partially blocks one of the bolts on the R160 and you have to remove it to gain access to the bolt. On the R180 you can just sneak a socket past the plastic vent so you don't need to remove it to get to the bolt.

As far as the "R160" referring to the ring gear as 160mm in diameter I guess that's the general idea but the ring gear isn't actually 160mm in diameter. It's actually less than 150mm at it's widest so I guess that 160 is a nominal designation. So why don't they call it R150? I dunno. I haven't measured a R180 ring gear so I don't know how that compares.

As Mychailo points out alex_umm has a few pictures of rear diffs in his locker. The pictures of the two rusty ones on a piece of cardboard clearly show two R160 diffs. The lower one is an earlier unit with the splined axle stubs sticking out of the case. These used the same kind of driveshafts as the front with the "female" inner ends.
In another folder there is a few pictures comparing the diff that alex took out of his SVX, which is clearly an R160. Next to it is the obviously larger R180 which, I take it, came from a USDM STi. Alex is in error refferring to both diffs in the picture as R180's.

To use the R180 diff you must also use the knuckles and axles that go with it. The driveshafts for the R180 are larger in diameter as are the splined shafts that slide into the differential on the inner end and into the hub on the outer end. They are only about a couple of millimeters larger in diameter but the wheel bearings are larger, too. So you couldn't use R160 driveshafts with an R180 because they would be too small. You wouldn't want to anyway because part of what makes the R180 setup stronger is that the axles are stronger and so are the wheel bearings.
Did you replace the knuckles and axles on your SVX with the STi pieces as well, alex?

As far as I know the 2004 USDM WRX STi is the first Subaru model in the U.S. to get the R180 rear end. Legacies did not get them, not even WRX's got them. Heck, in the rest of the world even standrd WRX's and Sti's didn't get them, they were only available in the STi RA versions. And, of course, in the SVX everywhere else in the world but here, apparently. Which is why I thought they might but Mychailo and I already figured this out a few weeks ago when I had him measure the bolt spacing on his rear diff. R160, bummer! And the pictures in alex_umm's locker also confirms it.

To address some other comments/questions:

alex_umm, the rear diff that came out of your SVX is the same as the one from the '91 Legacy, both R160.

svxsubaru1, the R180 is twenty stronger than the R160.;)

jamesy, the WRX diff (non STi) is just as strong as the USDM SVX diff. They are both R160's.

alex_umm, yes, the ring & pinion gears from an R160 can be put into an R180 case. You can also put a Geo Metro engine into a Kenworth truck engine bay but that doesn't mean you could actually bolt it up to anything and make the truck move! That's an extreme example but I think you get the point. It ain't gonna work.


Oh, and just by way of introduction because I realized you guys could be thinking, "Why should I listen to him, he could be some wanker, too." I build and maintain rally cars for a living. I've built several Subarus, including national and divisional championship winning cars and I was part of the Subaru Canada Rally Team in 2001. So I've been around this stuff a little bit. Not trying to sound high and mighty, just giving some credentials to lend validity to what I stated above.

-Dave Clark

[svxsubaru1]

Thanks, i was wondering why subaru would put a r180 in a 135 horse 1 gen legacy.

[Subafreak]

OK then Mr. high and mighty:D What the hell is the little rear diff with the screw in bearing caps that i'v been told about but never seen? an R140?:rolleyes:


Did you say that every other SVX came with an R180 but the USDM's? :mad:

[oppositelock]

Originally posted by Subafreak
OK then Mr. high and mighty:D What the hell is the little rear diff with the screw in bearing caps that i'v been told about but never seen? an R140?:rolleyes:


R160, just older, like from a Loyale.




Did you say that every other SVX came with an R180 but the USDM's? :mad:

Apparently so.

[Subafreak]

I'v had as old as a 77 Brat and it still had bolt in rear caps. I'm begining to think this mystery rear does not exist.

[oab_au]

Using your measurements, the Euro/Australian version has an 3.7:1, R160 diff.

Harvey. ;)

[oppositelock]

Originally posted by Subafreak
I'v had as old as a 77 Brat and it still had bolt in rear caps. I'm begining to think this mystery rear does not exist.


Well I agree, I don't know that I've ever seen a Subaru rear diff with screw in bearing cups. The front, of course, is like this.

Certainly the older diffs have the splined stub shafts like the front.

BTW, the R160, R180, R200, etc. diffs are made by Hitachi and came in a number of different vehicles, mainly Nissans (and Subarus, of course). 280Z's had R200's , some had R180's. I'm not a Nissan guy so I don't really know exactly what came in what. But if you got an R180 out of a Z car it would physically bolt into a Subaru. Whether the gear ratio would match up or the axles would fit is another matter...

-DC

[oppositelock]

Originally posted by oab_au
Using your measurements, the Euro/Australian version has an 3.7:1, R160 diff.

Harvey. ;)

Well that's pretty interesting because it was a supplier of mine in Australia that thought that the SVX's (down there at least) came with R180's. I guess "thought" was the key word.

-DC

[svxsubaru1]

Dosent the rear diff say on the pice of plastic on the rear cap weither the diff is a r180, or r160?

[oppositelock]

Originally posted by svxsubaru1
Dosent the rear diff say on the pice of plastic on the rear cap weither the diff is a r180, or r160?

Piece of plastic? Do you mean the decal on the rear cover that is sometimes there, more often not? I found an older diff with a decal but it just listed the part number and the gear ratio. Most diffs don't have a decal. Otherwise the only plastic part on the diff is the vent breather and there are no markings on that.

Anyway, I already outlined how to tell the difference above.

-DC