While researching for a potential modification (making hybrid axles), I found it very difficult to get good information on OEM Subaru CV axles. Most of the info was scattered across various forums and even then it was inconsistent. So to make heads or tails of this information I decided to put it into a table.
I will update this table as I find new information.
Starting with GD chassis, WRX rear axles (aka – 5×100/R160) have 24/25 spline rear axles. The GR chassis switched to bolt-in bearings with 27 splines so the GR WRX (08-14) has 27/25 rear axles. All STIs as far as I can tell have 27/27 rear axles. The LGT Spec B with the R180 has unique 25/27 rear axles.
|Year||Model||Axle Location||Outer CV Joint Splines (Hub)||Inner CV Joint Splines (Trans/Diff)||Shaft Size||Shaft Spline Count|
|2002-2005||WRX (Sedan)||Front||27||—||28mm||29?||#1, #7|
|2002-2005||WRX||Rear||24||25||24mm||21 or 22|
|2006-2009||LGT Spec B||Rear||25||27|