Pinion Nut Size

[Kansan]

I have a '73 Cuda with the 8/34 sure-grip 489 case. My pinion nut seal is leaking and need to know what size the pinion nut is. If there are more than one size, please let me know.

Thanks,

Kansan

 

[john-9]

1973 Cuda if center section is original to the car should be 1-1/4 socket ,, and you will have a fine (29 ) spline yoke ,, if the center section has been changed at any point the early 489 cases were 10 spline and will have a 1-1/8 nut ,, if the center section has been rebuilt at any time it may have a 1-5/16 pinion nut for a fine (29 ) spline yoke as the rebuild kits may use the 1-5/16 nut .

 

[Kansan]

Perfect. Just what I was looking for. Thank you, John-9!

Kansan

 

[Litchkar]

this will cause some feedback, but 489 cases used a crush sleeve instead of shims to set lash. Re-installing the nut and yoke after changing the seal can cause a change in pinion preload. This causes a whinny noise when you take your foot off the gas. I experienced this when I bought a used third member and they changed the yolk size for me. Check out you tube video on 490 cases and crush sleeves.