3894568 Ring and Pinion Gear

[Jeff Z.]

3894568 9:41 GM 11 66 2

Thanks
Jeff

[Wayne M.]

Re: 3894568 Ring and Pinion Gear

...found what looks like a later dated 4:56 gear and posi unit. Can anyone verify the following part # is for 65 and up posi case. Haven’t had a chance to pull pinion gear to look at splines and crush sleeve length. Also date code doesn’t appear to be MDDYY.

3894568 9:41 GM 11 66 2 ....

Yes, that's the correct ring gear part # for '65-up to at least 1970. You might be able to look deep and see the pinion gear stamping as well; #3894566, and the month / date (the last digit is probably a shift or assembly station).

Here's a 4.56 set I have: ring '568', 12_65_1; pinion '566', 11_65. Both 9-41 teeth ratio.

[Gary F.]

Re: 3894568 Ring and Pinion Gear

I have a 4:11 in my 63, and here is what's on the ring gear.

1 - GM - 3733908 - 9 37 - 2 63

The car was built March 18th.