Resource: Subaru CV Axle Database

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.

Cliff Notes

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 (Outer/Inner)*	Axle Length	Source
1999	Forester	Rear	24	25	23mm			#5
2000-2002	RS	Rear	24	25	23mm			#1
2001	Legacy Outback
2002-2005	WRX (Sedan)	Front	27	—	28mm	29?		#1, #7
2002-2005	WRX	Rear	24	25	24mm	21 or 22
2004	STI	Front	27	27
2004	STI	Rear	27	27		30/30		#6
2005-2007	STI	Front	27			29?/30
2005-2007	STI	Rear	27	27
2006-2007	WRX	Front	27	25				#1
2006-2007	WRX	Rear	24			28
2008-2014	WRX	Front	27
2008-2014	WRX	Rear	27	25		28?		#3
2008- 2014	STI	Front	27
2015-202X	STI	Rear	27	27
2004	FXT	Rear	24	25		22		#4
2006-2009	LGT Spec B	Rear	25	27

Sources

1. https://forums.nasioc.com/forums/showthread.php?t=367808
2. http://wordpress.suberdave.com/?page_id=275
3. https://www.wrxforums.com/threads/r180-into-08-wrx.23397/
4. https://forums.nasioc.com/forums/showthread.php?t=2048240&page=8
5. https://forums.nasioc.com/forums/showpost.php?p=3969011&postcount=2
6. https://forums.hybridz.org/topic/73182-subaru-sti-r180-differential-and-axle-conversion-revised/
7. https://thefactoryfiveforum.com/showthread.php?11112-Internal-CV-Spline-Mismatch