HSHP-25K – 30 spline inner axle kit

Parts List:

• (2) 30 spline inner axles
• (2) 12 bolt c-clips
• (2) 10 vette thrust washer
• 30 spline spider gears
• (2) half shaft flanges

Once the differential is out of the car, you must pull the posi unit and completely disassemble it. The posi unit needs to be machined for the new larger side yokes to fit. Please read instructions thoroughly before proceeding to machining.

Dial indicator showing it’s true

Remove the carrier bearings, ring gear, plates and springs, then clutches.

Chuck the posi in a lathe and ensure it’s centered. Dial indicator is to make sure the unit is running true on the lathe before machining.

Machining Posi

Factory opening

Standard ID on the posi is around 1.247″.

New width of entire bore

This will need to be opened up to a diameter of 1.295″ for the new axles with a step cut coming next.

2nd step of posi machining – step in material for c-clip install

Remove .020 of material at a time for an additional .100″ opening

Continue opening the outer edge bore in .020″ increments until .100″ of material is removed creating a step that is .325″ deep.

Finished product

New step bore of 1.395″ that is .325″ deep

Your posi should now have a bore of 1.295″ and a step that is 1.395″ on the outer edge of the bore that is .325″ deep. This allows the new side yokes to be pushed in far enough to install the 12 bolt c-clips during assembly of the differential.

Clean up the hard edges

Finally, sand or file the hard edges and clean the posi before re-assembling.

Final product after machining