Do you have to set backlash and contact pattern when,

#1 when you replace axles
#2 when you replace a standard open diff with a posi ?

 

1. No.
2. Usually they will be pretty close but you should always check it anyway.

 

Thanks, i was hoping someone would say that. I should have been clearer in my post but when you say "Usually they will be pretty close but you should always check it anyway." The 'it' you are referring to is backlash correct ?

 

"it" refers to what you refer to in your thread title.

 

we all have our moments

 

Make sure to check the contact pattern before you swap the carriers. Some times people do what your planning on and then freak out because the contact pattern isnt "book ideal" when it wasent to begin with.

 

The contact pattern will remain the same unless the backlash was way out to begin with, then the pattern will change slightly. When installing a new carrier, runout should be checked, and fixed if it is off (out of spec limits). The side shims will give you the preload & backlash desired.