Pele

iTrader: (28)

So yeah... When rebuilding a differential, they have the pinion spacer... How do you know which one you need?

Is it trial and error? Put it together, drive, if it sounds like ***, tear it down and add another spacer?

How do you know if you need to add or remove a spacer?

Won't you wear **** out with this trial and error method?

xero

there should be a spec for the clearance between he meshing gears, you can probably find it in a FSM. You need to measure that and get that where it needs to be, then get a space for the other side to make so there is no play in the differential casing.

EDIT: I think this is actually how much backlash you have from one gear to the other, which can be measured with a dial indicator.

So, you need the clearence in spec and the casing squished/locked in place.

Use a caliper, if it's a hair to small, getting a spacer .001 or .002 bigger and sanding it down would work. That's how I did the one in my 240sx. I was actually able to use all the factory spacers from my open diff, just had to cut one down a couple thousanths.

good luck

lovintha7

Usually the factory spacers work. You're going to want .007-.012 in of backlash. Hold the pinion, and rock the ring gear back and forth (like the diff is turning). You want a little bit of play. Too much, and the gears will bind and wear out quick. Too little, and you will hear a nice loud "thunk" and some tore up gears.

Kentetsu

Haynes manual says that you should coat a few of the teeth with "engineer's lead" and then rotate that assy. Then you look at the pattern pressed onto the lead on those teeth to make sure they are meshing at the right point. My haynes has pictures showing what you do/do not want. Hope this helps.

lovintha7

There's also something called Prussian Blue.

Works really well. Napa carries it usually.