C6 transmission upgrade
Thread Starter
Cruising
Joined: Dec 2015
Posts: 13
Likes: 0
From: Brisbane Australia
C6 transmission upgrade
has anybody upgraded an 06 model T56 transmission to the later model (08) T6060. i started to but found the diff splines were different. is it just a case of upgrading the diff to the same year/model or do I then have to change axles. where does it end?
Thread Starter
Cruising
Joined: Dec 2015
Posts: 13
Likes: 0
From: Brisbane Australia
thanks for the reply Timd38, do you mean the axles splines? I haven't bought a diff yet but from what I have seen available they don't specify what they are out of. usually just ratio & year model. do you have any tips on buying one. as you can see its for a race car but on a budget (not LG's budget either).
Race Director
Joined: Aug 2005
Posts: 13,592
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From: Hudson WI
NCM Sinkhole Donor
The splines from the trans to the diff. Base manuals are 27 spline, auto and Z06 are 30 spline. If you are trying to use drive axles, say 2011 on 2006, GM changed ABS suppliers and changed the wheel bearing spline count at the same time, so they won't work.
Last edited by timd38; Jan 29, 2016 at 06:00 PM.
Former Vendor
Joined: Aug 2005
Posts: 16,897
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From: Lewisville TX
St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13
If it is the larger 30 spline output shaft then you could grab a Z06/GS diff. It would have different output shafts on it (if I recall right) so you would have to use a DSS half shaft and let them know what you have going on, or have them "punch" out a set of SKF bearings to work with the later half shafts with the larger splines at the bearing.
Thread Starter
Cruising
Joined: Dec 2015
Posts: 13
Likes: 0
From: Brisbane Australia
my car is a standard C6. has the T56 at them moment. i have bought a 6060 from unknown car but it doesnt fit because of the larger splines. looks like I'm up for a diff but want to limit it to that & not have to change axles etc etc.
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Thread Starter
Cruising
Joined: Dec 2015
Posts: 13
Likes: 0
From: Brisbane Australia
Race Director
Joined: Aug 2005
Posts: 13,592
Likes: 187
From: Hudson WI
NCM Sinkhole Donor
Sounds like you have a Z06 6060 and the splines won't line up. Based on what you said about your goals, sounds like you need 4:10 diff gears not different trans gears.
Race Director
Joined: Aug 2005
Posts: 13,592
Likes: 187
From: Hudson WI
NCM Sinkhole Donor
Thread Starter
Cruising
Joined: Dec 2015
Posts: 13
Likes: 0
From: Brisbane Australia
you might want to look at costs of transport from Australia. I know our dollar is crap at the moment but i think there would be more in the US at a good rate.
Thread Starter
Cruising
Joined: Dec 2015
Posts: 13
Likes: 0
From: Brisbane Australia
Race Director
Joined: Aug 2005
Posts: 13,592
Likes: 187
From: Hudson WI
NCM Sinkhole Donor
Not all 6060 have the same ratio, so if you want specific ratios, have one built with the ratios you want. To be frank, I think you are wasting your money and would put 4:10 gears in it.
Safety Car
Joined: May 2011
Posts: 3,807
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From: Oshawa, Ontario
decent price
a new 2008 Z06 differential with pump p/n 24238614 is available for $2558. which is 4% off their regular low price till Jan.31 from cheapestgmparts.com . your transmission will have to have 30 spline output shaft to fit this differential.your 06 axles will fit this differential.just completed this mod on my 05 yesterday
Last edited by irok; Jan 30, 2016 at 12:37 PM.
Race Director
Joined: Aug 2005
Posts: 13,592
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From: Hudson WI
NCM Sinkhole Donor
If I was you, I would to a specialist that understands what you want to do, what the RPM range is of you camshaft and get the ratios that you need in the trans and the diff for the track you plan to run. If you keep going down this path you are going to spend a ton of money and labor trying to figure it out.
Just my opinion.
Just my opinion.
Former Vendor
Joined: Aug 2005
Posts: 16,897
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From: Lewisville TX
St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13
Given the power of the car I would not go to a 4.10 rear gear.....and here is the reason if you are on a budget.
Strength
The Z06/GS/ZR1 all have a bigger ring and pinion but you are limited to a 3.42 rear gear ratio and I would try and use that gear if possible and I think you should be ok with it. You will get a lot more life from it.
Now you already have the Z06 gear box and it is not a bad box, and the ratios are going to be better than a Z51 setup for sure. I would look to add in a shorter 5th gear if the budget swings and you need 5th for the tracks you are running (say faster than 150 mph depending on tire and Redline).
If you had any choice but it had to be an H pattern I would have done the close ratio ZR1 gear box and then pick a diff based on the track, even if it meant going to a smaller ring and pinion just means you might need to keep a spare and they would have to be rebuilt more often.
Strength
The Z06/GS/ZR1 all have a bigger ring and pinion but you are limited to a 3.42 rear gear ratio and I would try and use that gear if possible and I think you should be ok with it. You will get a lot more life from it.
Now you already have the Z06 gear box and it is not a bad box, and the ratios are going to be better than a Z51 setup for sure. I would look to add in a shorter 5th gear if the budget swings and you need 5th for the tracks you are running (say faster than 150 mph depending on tire and Redline).
If you had any choice but it had to be an H pattern I would have done the close ratio ZR1 gear box and then pick a diff based on the track, even if it meant going to a smaller ring and pinion just means you might need to keep a spare and they would have to be rebuilt more often.