HLSD install (backlash question)

[MakotoS13]

okay guys here it is. i dont have a backlash gauge to check it but i want to make sure before i put this pumpkin back in the car.

so i have the S15 HLSD diff in the pumpkin, ring gear on, and bolted in. now, there's a fat shim and two thin ones. the fat one has to stay on its side because its like a .25 inch shim and thats almost the height of the teeth on the ring gear. i would think that if you got it backwards the teeth would barely touch and you'd grind em off, in any case i'm double checking.

i'm basically eyeballing the backlash. its barely visible wtih the naked eye. like, you have to stare at one spot and move the ring gear while holding the pinion gear to even see the slightest movement. this should be less than 1mm but i have no way of knowing scientifically since i lack the backlash gauge. you can feel it and hear it but the movement just isn't that much.


is this normal?

[S14DB]

You didn't listen to me did you?

[420sx]

should have bought the kaaz like i told you haha...... everything should just be a drop in. if u did everything right then dont worry about it. when we were putting in my friends hlsd in his s13 we had no problems.

[sdtouge]

there is that prussian blue stuff....

[TheTicTac]

Get the FSM, find the PD section and follow instructions.

[Rittmeister]

I installed an S15 diff in my S13 open casing. I re-installed the shims in exactly the order and orientation they came out. Not trusting myself I took it to my mechanic to look it over and everything checked out. It's back on the car and has been for a few thousand miles. Everything works great.

Every aftermarket diff install I've seen (SCC, nekopunch, others) have done the same - just put it all in like it was before - and I haven't heard of problems yet.

[MakotoS13]

i was just bein paranoid. its in and works GREAT!

[FRpilot]

this is a noob question... what is backlash

[SochBAT]

Correct me if im wrong. Backlash happens when your teeth and gears don't match up. It may start off small and tiny, but eventually, the gears will grind like R.Kelly and 10year olds. If you dig that, fine by me. But most don't.

[theicecreamdan]

hahaha, what a great analogy