rear diff info needed

[njdrsubaru]

hey guys and gas

 

i have a rear diff that i have no idea of what subie it came from... no numbers or stickers on the case or rear cover...

 

does anyone have info on the count the teeth inside to what the ratio is?

 

thanks in advance

[Fairtax4me]

It's pretty simple. Divide the big teeth by the little teeth. Post a picture of it, someone here might be able to tell a year range by looking at the case.

[torxxx]

my 4.44, 3.9 and 3.54 all had numbers imprinted on the ring gear. I dont remember the exact #'s 39x11 (3.54) was the #'s on the SVX before I swapped to the 4.44.

 

I really wish Subaru still put the ratio on the diff cover.. made things a lot easier

[ShawnW]

I etch it into the case on the ones I disassemble or rebuild now. Just silly to not have a ratio or a part number that is specific to the ratio on the case. Frustrating. Id just pull the rear cover bolts off and plan on resealing the back plate to verify. (using ring gear stamping indicated above by Torxxx.)

[porcupine73]

Is it possible to figure it out by turning the input or one of the stub shafts and counting the rotations of the other?

[njdrsubaru]

I opened it and the stamping says 37:9

 

that equals 4.11111

 

nice that's exactly what I needed

 

thanks guys

 

8)

[ShawnW]

Is it possible to figure it out by turning the input or one of the stub shafts and counting the rotations of the other?

 

Yes, but I never feel totally solid confident with this method like you get with reading it off the differential or ring gear.