well the pinion shaft went out on my rear diff,its a ford 9 inch 3.00 ratio.we bought a 69,9 inch with a 3.25 ratio.can we just put the new axle under it or swap the pinions or what?my truck is a 4x4 so the ratio difference screw up the front diff? i dont know the ratio of the front but i will go out tomorrow and look or later tonight.do the ratios need to match? ok thanks for any help.

 

They don't need to match exactly, and typically don't e.g. 4.09/4.11 but they need to be within a fraction of each other, 3.00/3.25 is too great a difference, in 4wd your drive train will bind up and something will inevitably break.

 

hmm well i might just take the front drive line out untill i get the right ratio diff,well the pinion from the 3.25 wouldnt work in the 3.00 at all?

 

It's unlikely the pinions even share the same tooth count, but even if they did the pinion and ring gear need to be replaced as a set.

 

but if i just took the front drive line and put the 3.25 it would be fine right?