Steering couplings/rag joints?

[bumble_76]

Hi all, I've decided to fit a 3rd gen Z28 or Trans Am steering box to my 75 TA to improve the feel. I know that I need to change the rag joint as the new steering box is 3/4 30 spline, but don't understand how these things work. Does anyone know if I just need a rag joint to suit a 3rd gen? Or do I need to splice the 2nd and 3rd gen rag joints together or something else?

[qik66]

Originally Posted by bumble_76

Hi all, I've decided to fit a 3rd gen Z28 or Trans Am steering box to my 75 TA to improve the feel. I know that I need to change the rag joint as the new steering box is 3/4 30 spline, but don't understand how these things work. Does anyone know if I just need a rag joint to suit a 3rd gen? Or do I need to splice the 2nd and 3rd gen rag joints together or something else?

Without actually see them I would suggest all you will need is the 3rd gen rag joint as I would think the only difference is spline size

[69JavelinMan]

Count the splines on the box and on steering shaft, you can work it out from there. 3/4" is the diameter of the shaft, not the diameter of the splines.

[Geoff 4]

I can only speak for power steering GM boxes.
The rag joints are the same. Early GM cars used a 13/16" spline out of the box, but that was changed around 1967 to 3/4" & has remained unchanged.

[bumble_76]

Thanks for the replies people. I ended up using the rag joint out of an 80s chevy truck with has the same steering shaft side as the TA but the correct spline side to suit the 3rd gen box. Dorman PN 31011.