Jump to content
SAU Community
  • Welcome to SAU Community

    Welcome to SAU Community, like most online communities you must register to view or post in our community, but don't worry this is a simple free process that requires minimal information for you to signup. Be apart of SAU Community by signing in or creating an account.

    • Start new topics and reply to others
    • Subscribe to topics and forums to get email updates
    • Get your own profile page, build reputation and make new friends
    • Send personal messages to other members.
    • See fewer ads!

    Consider joining our newsletter for the latest content updates

    Click here to register


OS giken 26 spline input shaft compatibility

Recommended Posts

Hopeing someone can help me out here, 

so I have a 1-3 PAR straight cut synchro gearset, with standard input shaft/4th gear and standard 5th 


my question is, can the OS giken updated 26 spline input shaft be used with factory 4th gear ? Or specifically only for OS gearsets?


here’s a pic of the OEM item and OS item 




Edited by SiR_RB
Link to post
Share on other sites

Never mind found a pic of my internals and it’s a PAR 4th helical and doesn’t look factory 

Link to post
Share on other sites

No it won't, I'm sure they use a different tooth count and angle on the helical input with PAR and PPG synchro gearsets. It's all to do with the counter shaft gear which OS giken matches to the standard Nissan profile. You can use a stock Nissan input on an OS gearset, or an OS reinforced input on a stock box (not that you ever would).

Also be careful with ''reinforced input shaft", as OS giken do a reinforced input shaft in both standard Nissan 24 spline and GM 26 spline. PM me if you want to know more, but an OS giken uprated shaft even in 26 spline is still much smaller before the spline on the shaft area, than say a PPG or PAR 26 spline input shaft is.

You have a PAR gearset, you need a PAR 26 spline input shaft.

  • Like 1
Link to post
Share on other sites

Yep ur right 

confirmed that my input/4th is a par helical part and much more beefy then then the stock part

still a billet input but 24spline 

Link to post
Share on other sites

So yeah in your case the 24 spline 25.4mm section itself is the weakest part as opposed to a stock or even OS giken uprated shaft having its weakest part before the spline.

So even your 24 spline input is still a pretty beefy shaft 👍

  • Like 1
Link to post
Share on other sites

I bit the bullet and got in contact with par and he sent the guys building my gearbox the 26 spline input shaft


may aswell do it all properly now that the box is out 

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Create New...