So I have finally gone with Fuji's advice and decided to keep the 4.444 final ratio for the wagon. This means I need to re gear my rear diff from the stock 4.111. While I am changing the rear ratio, I figured I would dump in a torsen LSD while I am at it. Acquiring a stock LSD rear end is quite easy, but not so much from a GDA/GGA. This is because the only GD/GG that came with a LSD stock has a R180 diff. I was thinking about swapping in a diff from a Leggy GT-B or B4. Does anyone have any information on this swap. I can't find much on NASIOC, and would rather discuss it in a much more local forum.
That is the route I will take if nothing else works out. The reason being is I can pick up B4 and GT-B rear ends for under $100. IF it works I can save my time with shimming, and rebuild rear ends for better things in life.
I think you are better off finding a WHOLE R160 rear diff that's 4.444 to begin with. Then all you have to do is take out the pumpkin, take off the ring gear, and slap that ring gear on a new diff. Also don't forget to put NEW bearings in, unless you want to swap your side bearings from your stock pumkin over as well. I would imagine that the regular WRX GDA has the viscous unit while the STi GDB has the clutch type LSD. For my with all my rear diff swaps and yadda yadda..... I just swap the WHOLE diff instead of taking it apart to swap ring/pinion gears. humm....I have a 3.900, 4.111, and 4.444 rear diffs. I swap them in and out whenever I do crazy stuff. I've inspected the rear diff before a little bit (I HAVEN'T TAKEN IT APART, but I've reviewed the service manual for it a while back on the computer at school). You take out the hub off the front via LARGE nut, then take the rear cover off, loosen the SIDE caps and pull off (they have SHIMS), you have to turn/rotate the diff so it can be pulled out, then you should be able to press out the pinion gear. There IS a seal at the end of it behind the hub.
Finding a GDA rear diff in 4.444 and LSD is quite difficult here. But, I can find a ****-ton of R160's from B4 RSK and GT-B's. Are the carriers and spline count the same?
Maybe I don't understand your build completely due to all the crazy acronyms but I am running an LSD R160 4.444 FD in my WRX. It came out of a Baja Turbo but the Forester XTs are the same. Bolted right in.
You don't have to replace the bearings if you tear it down. You can determine if you need spend $200 on bearings when you tear it down. The backlash is something to be aware of when you are going through it. LSD diff cases are ground in a couple spots to allow clearance t take the unit out. You are better off moving the 4.444 ring and pinion over to the LSD unit and case. Keep the shims on the side covers/races until you are ready t clean it all and put it back together.. They should be labeled on the inside R or L. The pinion doesn't have to be pressed out, a decent hammer or deadblow works just fine as long as you don't mangle the threads. Also, the companion flange changes at some point, so make sure you are putting the correct one on during reassembly.
Okay.... I bought an everything needed to swap out my wifes transmission (auto) from her '02 WRX Wagon (GGA) I now have a 5spd sourced from a 2004 "WRX 2003 V-Limited" Sedan (GDA) Which has a ratio set between RA gears, and stock WRX gears. This is coupled with a 4.444 final ratio on the front differential. The stock automatic in the car now has a final ratio of 4.111, which will not mate well with the 4.444 of the 5spd. I had intended on changing out the front ring and pinion, while installing a quaife and the 4.111 final ratio. My wife has now informed me that she wouldn't mind the 4.444 final ratios, so I am looking for a new rear end. I have not seen the Baja Turbo in 5 years on Japanese soil, so that is right out. The forrester XT (SG9) have not found their way to the junk yards yet. This is leaving me with the need to find different sources. Legecy GT-B, and B4 RSK's are a dime a dozen in the junk yards, and I can easily yank one of their rear ends out for under $200. I just need to know if there is anything different in the spline count/axle diameter, input flange, and mounting points, than found in the '02 WRX. I will keep looking for a 4.444 LSD rear end from the Baja or Forrester, but I would like the easy way out. I still may tear my trans apart, and if I do then a regear down to 4.111 will be going in. Also... did the MY 02 WRX auto have a LSD rear diff?
Any R160 should mount up in your rear crossmember just fine. Just be wary of the studs on the cover, as they varied between imprezas and legacys throughout the years. Axels shouldn't be a problem either. I believe all the newer stuff has the stubs on the axels. You'll have to check the companion(input) flange to make sure you have the correct one. This isn't too difficult to change.
what vehicle... I may swap out my Quaife LSD and find a used stock rear end for my 03 wrx when I trade it... its like a $1500 rear end... that I would do a good deal with anyone for a trade of a stocker plus cash... (if I pursue this forester option)
