Differential in Catalina

[chromebumpers]

Looks like NK GO81 2 I can't tell if that's a digit after the 2? What do you make of it?

 

[87vette81big]

View attachment 5982 I managed to capture the ID numbers on the pass side axle tube. I can expand the photo and see it well. However - where can I get a complete listing of codes?

Original GM Service Manuals from1971-81.
Definitely not the original 1968 Catalina rear Differential.
Its s later GM 8.5---8-1/2".
BEST TO REMOVE THE DIFF COVER AND COUNT THE GEAR TEETH.
NO FOR SURE IF POSI OR NOT.
IF ORIGINAL GEARS THE RING GEAR WILL BE STAMPED DATE CODED.

 

[chromebumpers]

I beginning to get, Well, discouraged about this car.

 

[chromebumpers]

What is the replacement gasket, or is it better just to use Permaseal?

 

[chromebumpers]

 

[chromebumpers]

The moment the cover came loose the oil ran out clean and clear.
Not sure which gears yo wanted counted but these are the numbers on the large center gear
GM10 373 R8 773 Side note: the "8" looked funny but I can't tell what else it is?


On the pinion gear someone etched 280. And when spun 180 degrees 4.25.0 Or 4250 ?

The part where the large ring gear attaches has a computer etched EATON 19557-1 05/08/02 A

Looks brand new inside. Not one scratch or nick on any part or surface.

 

[87vette81big]

Its a Custom built GM 10-BOLT 8-1/2 " REAR.
3.73 GM NOS GEARS USED.
BRAND NEW AFTERMARKET EATON PISI TRACTION UNIT.

ABSOLUTELY NOTHING TO BITCH OR WHINE ABOUT RICHARD.

 

[chromebumpers]

I wasn't Brian. I just wanted to know what it was.

 

[87vette81big]

The GM 10-bolts made from 1964-70-71 8.2 " were kinda crappy weak.
Known to blow out with a heavy right foot burning Rubber.
Pontiac built thier own version for the GTO & FIREBIRD.
SLIGHT BETTER BUT NOT GREAT.