2005 and 2006 rear diff inerchangeable???
Thread Starter
Tech Contributor
Joined: Mar 2003
Posts: 12,094
Likes: 197
From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
In some cultures, family members get eaten.
Collections Hold
Joined: Aug 2002
Posts: 2,899
Likes: 6
From: Fort Wayne Indiana
That answers the question of why you say they are interchangeable.
Cartek had already posted pictures (2 months earlier than your 2/13/06 thread) of the new mounting pattern for the newer 2006 which later went on to show the new ones would not be interchangeable (for any meaningful strength gains). It was this that I based my opinion which remains unchanged that for those interested in a strength gain in the case the newer 2006 cases (which account for 90% of the cars made that year) do not fit the 2005 model year's 5 bolt pattern.
The odd ball combo's today are the exception and not the norm due to the number of cars that were made.
Your dilema is obviously that if a guy with a transitional car asks you for a diff you cant send him one without knowing what is in the car. This is not what a guy like me was asking for. I had a weak 5 bolt rear and wanted a newer design 2006 with the different mounting pattern. To me are those interchangeable?....no it wont bolt up. 2 very different animals. From that point of view (a guy wanting a stronger diff for a 5 bolt pattern 05 diff they arent interchangeable). It was too broad a generalization to stick to today and would certainly cause more confusion than help. A better sttement today would be that while some 2005-2006 diffs were interchangeable the majority arent due to bolt pattern changes after a certain date when stronger diffs became available.
On the Z06 rear diff issue, the transmission output shaft is different too? I was just PM'ed that.
Cartek had already posted pictures (2 months earlier than your 2/13/06 thread) of the new mounting pattern for the newer 2006 which later went on to show the new ones would not be interchangeable (for any meaningful strength gains). It was this that I based my opinion which remains unchanged that for those interested in a strength gain in the case the newer 2006 cases (which account for 90% of the cars made that year) do not fit the 2005 model year's 5 bolt pattern.
The odd ball combo's today are the exception and not the norm due to the number of cars that were made.
Your dilema is obviously that if a guy with a transitional car asks you for a diff you cant send him one without knowing what is in the car. This is not what a guy like me was asking for. I had a weak 5 bolt rear and wanted a newer design 2006 with the different mounting pattern. To me are those interchangeable?....no it wont bolt up. 2 very different animals. From that point of view (a guy wanting a stronger diff for a 5 bolt pattern 05 diff they arent interchangeable). It was too broad a generalization to stick to today and would certainly cause more confusion than help. A better sttement today would be that while some 2005-2006 diffs were interchangeable the majority arent due to bolt pattern changes after a certain date when stronger diffs became available.
On the Z06 rear diff issue, the transmission output shaft is different too? I was just PM'ed that.
Yes, the C6Z transmission output shaft is different and that's why I labled them as the 30-spline design a couple of posts ago, to show the difference. The 1997-2007 LS1/LS6/LS2 manual transmission-equipped vehicles all share the same 27-spline transmission output shaft. There are additional internal design changes for that "LS7" trans. also that I'm aware of, but a tranny shop could better describe those in greater detail than I.
Last edited by DTE Powertrain; May 10, 2007 at 12:27 PM.
Drifting
Joined: Nov 2004
Posts: 1,753
Likes: 2
From: Fresno CA
Thought you guys might want to see a post with some actual info in it
The rear on the left is the used 05 3:42 diff from a manual tranny car, the rear on the right is the 2:73 gear box from my automatic (June of 04 production) very early production car. The manual tranny rear end actally has solid spots on the front of the case bottom and on the top (cant see the top solid area in the pic) It seems to be a beefier case compared to my original case? I went 11.80's with the 2:73 gears, now the car feels real strong! Hope to get this thing around 11.50 next time out with the 3:42 gears.
The rear on the left is the used 05 3:42 diff from a manual tranny car, the rear on the right is the 2:73 gear box from my automatic (June of 04 production) very early production car. The manual tranny rear end actally has solid spots on the front of the case bottom and on the top (cant see the top solid area in the pic) It seems to be a beefier case compared to my original case? I went 11.80's with the 2:73 gears, now the car feels real strong! Hope to get this thing around 11.50 next time out with the 3:42 gears.
