Factory 3.42 rear axle?

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Red78Calais4speed

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Feb 16, 2013
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While thumbing through my 1979 Oldsmobile chassis manual I saw the chart with the available axles for the year. There's a 3.42 listed for all Cutlass models but none of my other factory literature (dealer album, spec book, brochures, etc.) shows this application being used behind any engine/transmission combo for the year. Has anyone seen one? Does anyone have a build sheet with the GU6 code on it for this axle? The chassis manual lists the codes 2AE, and 2BE (limited slip version) so I'm guessing some were built. If so, with what drivetrain combo?

DSCN1108.JPG DSCN1125 (2).JPG
 

565bbchevy

Geezer
Aug 8, 2011
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While thumbing through my 1979 Oldsmobile chassis manual I saw the chart with the available axles for the year
I read this as you were only looking for a 1979 application of this?
 
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Red78Calais4speed

Greasemonkey
Feb 16, 2013
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Leominster, Massachusetts
I read this as you were only looking for a 1979 application of this?
Yes, if there is an application. I have all of the Oldsmobile chassis manuals from 1973-88 and 1979 is the only year that lists the 3.42 gears for Cutlass applications from the factory. Codes were designated for the axle assemblies and they were included in the manual so I have to guess that they were actually produced. All the other literature contradicts this. The 3.42 gear set doesn't show up in any of the factory combos. The deepest gear set was the 3.23 but only with the 231 V6 with automatic and the Y72 HD cooling option.
 

Red78Calais4speed

Greasemonkey
Feb 16, 2013
134
226
43
Leominster, Massachusetts
Here's a picture from the 1987 Olds chassis manual. No 3.42's are listed. 3.73's (8.5 inch) from the 442, yes, but no 3.42's. I know the 3.42's were in the Grand Nationals and T-types.

DSCN1128.JPG
 
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L92 OLDS

Comic Book Super Hero
Mar 30, 2012
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Here's a picture from the 1987 Olds chassis manual. No 3.42's are listed. 3.73's (8.5 inch) from the 442, yes, but no 3.42's. I know the 3.42's were in the Grand Nationals and T-types.

View attachment 165674
I’m wrong then. I do know they were over 3 so it’s likely they were 3.23. My bad
 

PBGBodyFan

G-Body Guru
Mar 3, 2009
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3.08’s were the highest numeric gear for base model g-bodies, at least from the early 80’s to the end. Some early years could have 3.23 or 3.42 depending on the combo, as shown.
 
Oct 14, 2008
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I’m wrong then. I do know they were over 3 so it’s likely they were 3.23. My bad
In 88 there was a 2.56 standard and 3.08 was the only option. My 88 was a 2.56 open.
 

Jim Rockford

Master Mechanic
Nov 10, 2007
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I know my 86 bonnie only listed 3.08 as the performance rear axle ratio, but it wasnt available with the 5.0 ..lol Nothing higher than that was available.
 

69hurstolds

Geezer
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Jan 2, 2006
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In the 80s, "performance" rears were 8.5" 10 bolts had 3.42 (GN) or 3.73 (H/O and 442). 7.5" 10 bolts had 3.73 in the Monte SS.

As far as parts book info, I can find 3.73, 4.10, and 5.00 ring and pinion gears for A body, but only for 1976 with 8.5" rear end.

3.23 was as deep as they went for 1979 A-body applications. But that doesn't always mean anything.

No 79 Olds model I can think of came with 3.42 from the factory. Nada. Zip. Were there any? Who knows? It's always possible. Technical documentation is proposed and written years in advance of the actual production year. The brochures and ordering information for sales can and did change, sometimes a lot. Which means, you almost could get a Turbo 81 Cutlass (hood is in the parts books) but no way in hell they actually made any for production. Same with the euro nose and Monte style mirrors on the 86 Cutlass. Never happened. And I think, although I'm not sure and not willing to pull out the CSM to look, the 442 in 85 had different gearing ratios in the governor/speedometer assembly. I could be wrong, but something wasn't passing the smell test.

I think this is just another anomaly that will go down in Cutlass lore.
 
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