Changing the crown and pinion gear

**Sndman77** · 25-11-2011, 12:10 PM

Hi

I was just wondering, can the crown and pinion gear be change in any holden diff (hq to wb - 10 bolt diff).
If I had a 2.60 ratio diff and I want to change it to a 3.08 0r 3.55 ratio, by changing the crown and pinion.
Can this be done?????

I thought I have read, that you can change the crown and pinion on diff, up or down on diff within the range of 3.08,3,36 aand 3.55.
I thought I have read you can't on the 2.60 and 2.78 diff, as the diff housing is different (somethhing to do with the crown and pinion).
Is this correct or I have miss read the info???????

Any correct information about changing the crown and pinion gear would be very helpful.

**HK1837** · 25-11-2011, 01:03 PM

Hemispheres are different. 2.60 and 2.78 share a hemisphere (LSD and open are different too). 3.308, 3.36, 3.55, 3.90 and 4.44 share the same hemisphere. Housings are the same for all centres for the same series/vehicle.

**Sndman77** · 25-11-2011, 01:56 PM

Thanks for your reply

Is the "Hemisphere", is what the crown gear bolt onto??????

Does that mean I can remove all the inner gear setup in the 2.60 or 2.78 ratio diff (Hemispheres, cown and pinion) and replace it with any the following diff ratio setup (3.08 to 4.44 ratio Hemispheres, cown and pinion).