differential gears

Post by **Peetee** » Mon Oct 30, 2006 8:09 pm

I am curious what componants different differentails share. Obviously the crown wheels differ on a 3.9 and 4.22 diff but are the pinion gears common to both?

Post by **wanderinstar** » Tue Oct 31, 2006 5:01 pm

Would think not. Because you fit a crownwheel and pinion as a set. If I remember correctly the numbers on the Diff eg 28/7, 31/6. the smaller no is no of teeth on pinion. Therefore if you try put a 6 tooth pinion where a 7 tooth one should be they wont mesh properly. ( the numbers are not correct, just for an example)
Ian.

Post by **JimK** » Tue Oct 31, 2006 5:09 pm

The different numbers of teeth on both pinions and crownwheels mean the teeth are at slightly different angles and it all gets very complicated.

Hypoid gears have some clever machining and geometry going on.

Post by **Peetee** » Tue Oct 31, 2006 7:54 pm

Sorry, maybe I'm getting my terms mixed up. I don't mean the gear on the end of the propshaft. It's the identical gears within the diff in line with the driveshafts.

Post by **bmcecosse** » Tue Oct 31, 2006 8:05 pm

Ahhh - the diff cage gears - likely these will be same for all - but that's just a guess.

Post by **JimK** » Tue Oct 31, 2006 8:09 pm

I think those are called planet gears, and I doubt there's any reason for them to be different between diffs.

Post by **minor_hickup** » Tue Oct 31, 2006 8:44 pm

I did see a crown wheel and pinion set sold as an upgrade to 3.7:1 gearing for the minor axle, so I would assume they are compatible.

Post by **Kevin** » Wed Nov 01, 2006 5:00 pm

Ahhh - the diff cage gears - likely these will be same for all - but that's just a guess.

That will be correct otherwise when you changed a diff you would also have to change the halfshafts.