Rear End ID

[Michael H.]

I just dragged home a complete rear suspension caliper to caliper and can't seem to find what ratio the chunk is from my information.

The two letters for the ratio code are NF which I don't see listed for any year. That is on the pass. side near the yoke. Behind those letters are 3899(or 8)143. The date is J187 which I believe is the one hundred and eighty seventh day of 1969.

The back cover has 3871375 with D118. The leaf spring has seven leaves. It's still assembled and in the back of my truck so turning and counting won't work for awhile. Any help appreciated.

[Joe L.]

Re: Rear End ID

I just dragged home a complete rear suspension caliper to caliper and can't seem to find what ratio the chunk is from my information.

The two letters for the ratio code are NF which I don't see listed for any year. That is on the pass. side near the yoke. Behind those letters are 3899(or 8)143. The date is J187 which I believe is the one hundred and eighty seventh day of 1969.

The back cover has 3871375 with D118. The leaf spring has seven leaves. It's still assembled and in the back of my truck so turning and counting won't work for awhile. Any help appreciated.

Michael-----

I think you're looking in the wrong place for the ID code. The ID code is STAMPED into the BOTTOM of the carrier case just forward of where the cover attaches. Often, it is lightly stamped and may now be obscured by corrosion. Take a wire brush to this area and report what you find.

The "NF" is probably a RAISED set of letters. It refers to the MATERIAL the part is cast from ("Nodular Ferris").

3899143 is the CASTING number of the carrier case used from 1967 to 1979. "J187" indicates a date of October 18, 1967. The cover is dated April 11, 1968.

[Michael H.]

Re: Rear End ID

[quote=Joe Lucia (12484);565677]
I think you're looking in the wrong place quote] Oh, that old prolbem.

Thanks, Joe, here's what it reads: 2 AV 4 19 68 V. I've tried to duplicate the spaces between letters and numerals like how it's stamped.

[Joe L.]

Re: Rear End ID

[quote=Michael Hill (23570);565679]

I think you're looking in the wrong place quote] Oh, that old prolbem.

Thanks, Joe, here's what it reads: 2 AV 4 19 68 V. I've tried to duplicate the spaces between letters and numerals like how it's stamped.

Michael------


Assuming that the gears inside the case are the same ones installed when the code was stamped at Chevrolet-Warren, it's a 3.08:1 ratio originally installed in 1968 427 Corvette. It should have the HD axles (i.e. the type that use cast iron caps retained by hex head bolts for u-joint attachment).

[Michael H.]

Re: Rear End ID

It has those caps and on the outers there's a flat c shaped piece that bends over the side of the nut, maybe they all have that? Thanks again Joe, I really appreciate your effort and info.

[Wayne M.]

Re: Rear End ID

..... here's what it reads: 2 AV 4 19 68 V. I've tried to duplicate the spaces between letters and numerals like how it's stamped.

Michael -- Here's another 3.08 ratio case, from an early '69 small block. Your "V" is probably a "W" for Warren Mich.

[Michael H.]

Re: Rear End ID

Hi Wayne - thanks for the pic but it is definetly AV.

[Joe L.]

Re: Rear End ID

Hi Wayne - thanks for the pic but it is definetly AV.

Michael------


I think Wayne was referring to the last character in the series you reported and not the second character of the ID code (i.e. "AV"). You report the last character of the series as a "V" and I think that Wayne is suggesting that it's likely a "W" and not a "V". All of these Corvette differential assemblies were manufactured at Chevrolet-Warren which is denoted as a "W".

[Gary R.]

Re: Rear End ID

Mike
I would pop the cover and take a look inside as well. Check the posi case and you can confirm the R&G, if GM it will be stamped GM, tooth count,and date.

[Michael H.]

Re: Rear End ID

Joe - I see what Wayne is saying, the V is very narrow like it was a little sideways when stamped.

Gary - thanks for that info, there's a lot of cleanup and disassembly to be done but for sure I'll do that.