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POSIRACTION REAR AXLE (02G81YA); SPECIAL REAR AXLE RATIO (02GS3AA);
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Re: What ratio is this?thanks RDR1969BB
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Re: What ratio is this?thanks RDR
Probably a 370 ratio with auto transmission. Best to jack it up and count the revs, input to output.................Comment
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Re: What ratio is this?thanks RDR
Those window sticker/tank sticker codes sometimes bear little resemblance to the real option codes, so I held back on this one a bit. In this case, however, the GS3 buried in the second set of numbers (02GS3AA) appears to identify this 69 differential ratio as 3.36:1 positraction.
On the bottom of the differential case, there should be an alphanumeric stamp. In that stamp, you should be able to see letter combinations of either AU (early 69) or CLR,CAU, or CAX (late 69/70). I am unfamiliar with these applications, so if find your code in the list above that's fine, but all of the codes may not be specifically applicable to your big block car.Comment
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Re: What ratio is this?thanks RDR
The automatic cars are strange, I have two that have "AX" codes not "CAX" and are early cars. Thanks for any help.RDRComment
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Re: What ratio is this?thanks RDR
Hmmm...That is strange...at least for me. It's probably makes perfect sense to Joe Lucia. The NCRS 1968-1982 Spec Book doesn't list an AX code for 68-early 69, but it does for later years 71/72...for those years, AX = 3.36:1.
The dates of manufacture should be the numbers following the gear ratio code(MM/DD/YY)...what dates do you have for these differentials?Comment
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Re: What ratio is this?thanks RDR
I wrote an atricle for the NCRS restorer years ago and had lots of comments verifying the AX code. Dating of the M 40 "CY" ( yellow tag ) trany was the main interest but the AX code kept coming up. I can resurect some pix if you still doubt, even the AX marking in the under body area. I have three of the 435 auto cars, I don't own the one I have questioned about and am not sure what the actual stamping is but it seems to be in the same zone with the AX stamping. These quirks seem to be related to the M40 Spec HP trany. Mine is 1AX date-W stamped and the tank sheet is two lines 02G88AA positraction axle 336R and directly under this is 02G81AA positraction axle 336R. My survey and article were almost 20 years age and were supported by Norris Wallace, Kevin Cavanaugh, Alan Kaplan, Hans Norberg and a very laate car stamped 2CAX 11 24 69 w owned by Ralph Spears,
thanks
RonnieComment
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Re: What ratio is this?thanks RDR
Chuck
the dates i have are 1ax122868w and2ax42869w
thanks
rdrComment
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Not Enough Experience Here To Doubt...
The AX code for an early 69 is simply outside of the realm of the NCRS published reference material I own, but it appears some individuals know or knew better. I'm not familiar with the 68-69 TIM&JG to know if this issue is addressed, and if the application of the AX code is given. I'm pretty sure the differential stamp isn't judged in NCRS, so update or correction of the specifications reference may not be seen as a pressing issue.
For future reference, your original question dealing with the ratio was answered by the list of factory options in Fact book of 1968-1972 Stingray by M. F. Dobbins. The complete differential code list is GS1 (2.73), GS2 (3.08), GS3(3.36), GS4 (3.70), GS5 (3.55?), GS? (4.11). Dobbins has an error because he lists GS5 for both 3.55:1 and 4.11:1, but the 3.36:1 seems to agree with your information.
If you have open eyes and ears, and an open mind, you can learn something every day in this hobby.Comment
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Re: Not Enough Experience Here To Doubt...
Chuck. AX is listed in the 68-9 JG as "3.36:1 HD P THM 427".
That translates as Heavy Duty (HD) Positraction (P) Turbo Hydra-Matic (THM) The Other Chuck.1963 Corvette Conv. 327/360 NCRS Top Flight
2006 Corvette Conv. Velocity Yellow NCRS Top Flight
1956 Chevy Sedan. 350/4 Speed Hot RodComment
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Thanks, Chuck...
It's good to see the 68-69 TIM&JG is on top of this, and it's the spec book is incomplete. Of course, maybe the new spec book issues are also updated. I haven't changed mine in forever, but you don't think the specs would be changing for cars that are mostly in the boneyard.Comment
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Re: Not Enough Experience Here To Doubt...
Is it Chuck and ReChuck or Chuck and UpChuck?Dick WhittingtonComment
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Yeah, I Know...Yer Gittin' A Little Payback!... *NM*
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