[trophyman]

Hello Guys,
I purchased a 39 Chevy with a GM differential in it that I'm removing. The numbers cast into the rear housing are 3894860N. The numbers stamped into the axle housing are P1 0109G2. Can anybody ID this differential for me.

Thanks
Pat

[bcm66]

From CRG...

http://www.camaros.org/drivetrain.shtml#axle

http://www.camaros.org/drivetrain.shtml#AxleCodes

It is a 67 or 68 Camaro 12 bolt, originally a 3.55 posi. What is the casting date?

Also, there should be an E under the PI 0109G2 stamped digits.

Is it PI or PL?

[trophyman]

Originally Posted by bcm66

From CRG...

http://www.camaros.org/drivetrain.shtml#axle

http://www.camaros.org/drivetrain.shtml#AxleCodes

It is a 67 or 68 Camaro 12 bolt, originally a 3.55 posi. What is the casting date?

Also, there should be an E under the PI 0109G2 stamped digits.

Is it PI or PL?

It's PI. Where do I find the casting date?? Under the above numbers there is a stamp "E"

Thanks
Pat

OK---according to the table, the casting date is January ninth. I think??????

[bcm66]

0109 is January 9th but the assembly date of the unit.

Casting date will be on the center section, in the "webbing" area. Like this...from CRG...



or this

[trophyman]

OK--looks like L268 or L269 hard to see the last number

[bcm66]

Can you post a picture or send it to me?

[bertfam]

More than likely it's L266, which would make it a 12 bolt out of a 67.

Ed

[trophyman]

Originally Posted by bertfam

More than likely it's L266, which would make it a 12 bolt out of a 67.

Ed

Nope--definitely not L266 I'll walk over to the shop and take a picture and post it here.

[bcm66]

On casting dates, often the 3, 8, 9 and sometimes 6 are hard to tell apart. But we will see.

Ed may be correct though, because L268 and L269 don't really fit for a 67 or 68 PI coded 12 bolt.

[trophyman]

OK--I stuck a small wire brush in my air grinder and cleaned it up a bit. Here is the pic.

Thanks

[bcm66]

Pat, what is the chance of getting a picture of the PI 0109G2 stamped area?

I would say it looks like L 26 8 but it is still not easy to say for sure.

Ed, what do you think?

[bertfam]

I blew it up and turned it 180 degrees and it's really hard to say. It could be an 8 or a 9, but you're right, a higher resolution picture would be great if possible.

The problem is the PI code for 1969 was a 10 bolt, and the PI code wasn't even used in 1970, so if it really is 1968 or 1969, I would say it's probably a service replacement axle housing. A better picture would go a long way in determining the year, along with the dates of the ring and pinion if you can get those and again, a higher resolution picture of the date.

Ed

[bcm66]

I am not positive, but I think the 3894860N casting number had been phased out before late December of 69.

[trophyman]

Sure--I'll take some pictures tomorrow, Sunday, and post them.

I'm using my Nikon D300 so the pics are very high res. Just need to make them smaller to post.

BTW, dont know if it means anything or not, as I said, the axel is in a 1939 Chevy chassis. The car was born, and spent all it's life, in Nevada. I'm sure that is where the differential was put in.

[Kurt S]

How deep are the spring perches? Assuming they are original, that would tell me a lot.