how can you tell what Final Drive Ratio a diff has?

[E7-S14]

are there any tell tale ways to find this out?i got a s13 diff out of a 180 in japan with a kazz 2way in it.

as far as i know the 180s came in 3 different f.d. g.r's3.94.114.41( i think im right on these)

how can i tell which one i have? are there any tell tale signs on the diffs?it was originally a Viscous lsd

[jdm_master_X]

i thought it was 4.08, 4.11, and 4.36 (uber hard to come by).

Best thing to do is turn your output shafts one time (the part your axles bolt to) and count how many times the pinion gear/driveshaft yoke spins. From there you can kinda get an idea what the ratio is.

[datsun2401972]

honestly I don't know, but I would think you could count the teeth and do a simple math equation to figure it out?

Or maybe after it's installed, put transmission in nuetral and while making one complete revolution of the drive shaft, determine how many times one half shaft revolves compaired to your driveshaft.

[jdm_master_X]

honestly I don't know, but I would think you could count the teeth and do a simple math equation to figure it out?

Or maybe after it's installed, put transmission in nuetral and while making one complete revolution of the drive shaft, determine how many times one half shaft revolves compaired to your driveshaft.

The half shaft is supposed to turn one time to however many times the worm gear turns. this is simply because the pinion gear is larger in comparison to the worm gear.

[E7-S14]

well.411 is Stamped on the diff in white.in a font similar to "Times New Roman"

so im beginning to think its that one..although i really wanted the 4.36 or 4.41 (which ever one it is.. the higher one)





but im guessing im going to be doing the turn the drive shaft trick to find out.

[adrianfromthecastle]

yeah, I was just about to say, turn the shaft part that the drive shaft attaches to and count the revolutions the half shafts do in one whole revolution of the drive shaft

[datsun2401972]

yay, we're pretty mart!

[jdm_master_X]

..where's pretty mart at? I wanna go.

[adrianfromthecastle]

yay, we're pretty mart!

who's mart? post pics, we'll determine whos pretty or not

[E7-S14]

well it turns a lil over 4 times to every half shaft turn.

so im guessing thats 4.1:1

for the 4.3:6 how many times would the half shaft turn?4 and .3 times?

so for the 4.1:1 the half shaft will turn 4 and .1 times?if this is the math then it becomes kinda hard to tell from just turning right?

[datsun2401972]

Probably easiest to make little hash marks around the axis. That'll make it easy to see if it's only turning one-tenth+ of a turn extra or one-third+ extra...

Wow, I got pwned...I have no good pics of any girls named mart, or any girls at all since I'm at work

[hai1206vn]

to be exact, open the pumpkin. The ring gear has numbers stamped on the edge, such as 49:12 (that's 4.08) which means 49 ring gear teeth and 12 pinion gear teeth. Here's mine when i installed the s15 lsd

[E7-S14]

to be exact, open the pumpkin. The ring gear has numbers stamped on the edge, such as 49:12 (that's 4.08) which means 49 ring gear teeth and 12 pinion gear teeth. Here's mine when i installed the s15 lsd

ok so what would 4.11 and 4.36 be?ill be opening the diff when i swap covers

[hai1206vn]

aw come on man, just like 49 / 12 = 4.08333. That stamped number tells you the ratio

btw the ring and pinion gears always come as a set, so 49:12 guarantees 49 and 12 teeth respectively
Modified by hai1206vn at 3:45 PM 12/20/2008