Why does this work? (s15 helical related)

[e1_griego]

My diff is NOT repeat NOT an s15 helical. It is from a Nissan, but apparently from a cedric/gloria. Those came with 29spline output shafts, but all s15 diffs require 30 spline!

Alex

I recently purchased an s15 helical (with output shafts) from a seller on ebay--got it for cheap too!

Went to a local shop to have it installed. After getting the internals all bolted in, it was time to put in the output shafts. One of the s15 ones had a bent lip, and was a tiny bit chewed up on the lip (looks like they were removed with a pry bar instead of a hammer--completely fixable though). In any event, we just stuff my open diff output shafts in, and they dropped right in and work fine!! This completely contradicts nearly everything I've read about the s15 helical.

(the dirtier output shaft is the stock open diff one)





So, what gives? The diff that was in it had recently changed fluid (at least it came out pretty clear looking). Both sets of output shafts fit the same way, with no forcing or anything at all. It's all bolted in and I've put nearly 1k miles on it since installed--no noises, no grinding, tons of grip. And what a sweet diff might I add!! Perfect for the driving I want to do (ie. not drift), silent, and gives great traction!

Just very curious as to why this works? The guys at the shop chalked it up to "don't believe anything/everything you read on the internet." I'm inclined to agree but it's all very interesting.

Thanks.

Alex