Anger

iTrader: (1)

My 83 GSL needs a new rear differential.
I found two on eBay. A 26 & a 24 spline.
Anyone know off hand what I should have?

Siraniko

iTrader: (13)

83 is a weird year since they switched to large axle mid-year. Its best to check if you have a large or small axle.

Anger

iTrader: (1)

Where would I be checking?
Outside OD?
I don't really want to pull my axle.
Just have the diff installed.

Siraniko

iTrader: (13)

Easiest way is to remove the gease cap from the front hub. Look at the spindle nut. If its a regular nut, its a small axle. Large axle spindle nut look like this one.

Anger

iTrader: (1)

My nut Looks like this w/ a foil castle nut & pin.
Assuming I have a small axle then.

Need to pull the trigger on a differential.

Siraniko

iTrader: (13)

..if the driveshaft to diffy flange bolt has a nut on the other side, it is a large axle. Small axle has a threaded diffy or pinion flange.

Anger

iTrader: (1)

I've nuts on the front side, motor side.

Sgt.Stinkfist

iTrader: (6)

in 83 there were both, i have an early 83 axle that has the late model non-threaded pinion flange that has a square bolt pattern and requires a nut/bolt combo to attach the driveshaft, yet it is the small spline/small bearing axle

Siraniko

iTrader: (13)

Thatt was onmy first post that an 83 has mixed up parts and the one above ur post is based on a typical scenario for parts identification.

Anger

iTrader: (1)

Just an update & for future reference, it was 24 spline.

All is well in my world - my FB runs & drives better than I've ever known.

peejay

83 will have small splines (like early) and square driveshaft flanges (like late). The only midyear change in that timeframe was the '84 models which had fine-tooth gearsets for a few months. (3.933 instead of 3.909, and some similar difference for GSL-SE)