i just bought a posi. it came with gears. i was told the gears are 2.73 gears. i have an open 3.73 rearend i want to put the posi in. my 3.73 gears are thick. and my 2.73 gears are thin. i was told this is supposed to be opposite. please help me.

 

and this one

 

The 3.73's are on a 2-series carrier, correct?

 

i don't knwo how to tell. the 3.73 gears are the thick ones,on the open diff. both ring gears have the same number of teeth but are different thicknesses. i don't know what is up. if some one has gears they could measure or get a pic of i would appreciate it.

 

has anyone run into this before?

 

i believe, afaik
3.08 < use a series 2 carrier
and 3.23 > use series 3
the gears are different for each one

though i dunno about your particular setup..

 

are my 3.73 gears overthick or are they the right size? How do i tell if the carrier i have is a 2 or 3 series?

 

3:73 Gears = 3 series carrier. And what you are trying to do will not work, you can not mix 2 & 3 series parts together.

 

i was told that i could use a spacer to make the 3 series gears work on a 2 series diff. but i am wondering why 3 series gears are so thick compared to the 2 series gear i got with the diff. Thanks

 

The ring gear is thicker because the pinion head is smaller in diameter. Lower gears (2.73, 3.08, etc) have a huge pinion head. Higher gears (3.73, 4.10, 4.88 etc) have a tiny pinion head. GM had different carriers to allow different ratios without enging up with an impossibly small pinion head or an incredibly massive ring gear, instead the different series carriers move the ring gear mounting pad side to side to account for some of the difference.

You can use 3 series gears on a 2 series carrier by either using gears made for this swap (thick ring gear) or a spacer. You can't use 3 series gears on a 2 series carrier, because you can't make the gear thinner.

 

What I was thinking was those 3.73's are made for and mounted on a 2-series carrier. But, I haven't seen enough of them to know for sure.

 

ok... I think i understand now. the reason the ring gear on the 3.73 gears is so thick,is because the pinon gear is so small. ok. i get it. i have to get a spacer, a new set of gears, or a new posi unit. Thank you very much.