anyone break a 2005 A4 diff drag racing?
Thread Starter
Melting Slicks
Joined: Jan 2005
Posts: 2,326
Likes: 5
From: louisville "derby city" kentucky
anyone break a 2005 A4 diff drag racing?
i am trying to learn if anyone has broken the diff case on a 2005 A4 with a 3600 stall and 305/30/18 tires. want to change the ring and pinion to a 3.73, but i want the use the stock case. reason why is i don't want to pay an additional 550.00 for an adapter plate to upgrade the case. any input is welcome. thanks, cranky 
Team Owner
Joined: Feb 2001
Posts: 27,254
Likes: 136
From: Short Hills, NJ
It's not quite as common in the automatics as it is in the manuals but it has still happened.
If I were staying with the 3.15s/2.73s and at stock/near stock power levels I would probably just keep the '05 case but if doing gears/rebuilding the rear anyway, I would take the plunge and upgrade the case to one of the newer ones as well. It's certainly not a cheap endeavor (that adapter plate you speak of plus a new case and possibly side covers too) but it can also help avoid breaking at/oiling down the track and worse yet, possibly taking out your transmission as well while doing so.
If I were staying with the 3.15s/2.73s and at stock/near stock power levels I would probably just keep the '05 case but if doing gears/rebuilding the rear anyway, I would take the plunge and upgrade the case to one of the newer ones as well. It's certainly not a cheap endeavor (that adapter plate you speak of plus a new case and possibly side covers too) but it can also help avoid breaking at/oiling down the track and worse yet, possibly taking out your transmission as well while doing so.
Thread Starter
Melting Slicks
Joined: Jan 2005
Posts: 2,326
Likes: 5
From: louisville "derby city" kentucky
It's not quite as common in the automatics as it is in the manuals but it has still happened.
If I were staying with the 3.15s/2.73s and at stock/near stock power levels I would probably just keep the '05 case but if doing gears/rebuilding the rear anyway, I would take the plunge and upgrade the case to one of the newer ones as well. It's certainly not a cheap endeavor (that adapter plate you speak of plus a new case and possibly side covers too) but it can also help avoid breaking at/oiling down the track and worse yet, possibly taking out your transmission as well while doing so.
If I were staying with the 3.15s/2.73s and at stock/near stock power levels I would probably just keep the '05 case but if doing gears/rebuilding the rear anyway, I would take the plunge and upgrade the case to one of the newer ones as well. It's certainly not a cheap endeavor (that adapter plate you speak of plus a new case and possibly side covers too) but it can also help avoid breaking at/oiling down the track and worse yet, possibly taking out your transmission as well while doing so.
Team Owner
Joined: Feb 2001
Posts: 27,254
Likes: 136
From: Short Hills, NJ
Thread Starter
Melting Slicks
Joined: Jan 2005
Posts: 2,326
Likes: 5
From: louisville "derby city" kentucky
Oh ok, so you are making enough power to do some damage. Dennis's ('dennis50nj') car, also an '05 automatic, made it well into the 10s on the '05 rear (with properly installed 3.73s) so you probably have some time before you need to worry, unless you wheel hop it bad on one pass or something of course. But with those low 1.4x sixty foots his eventually did let go and he had to spend the extra money upgrading it anyway so it might be best (cheaper) to do it all at once.
Team Owner
Joined: Feb 2001
Posts: 27,254
Likes: 136
From: Short Hills, NJ
Just got to be careful with the water box, pressures, burnouts and maintaining/changing the fluid.
Thread Starter
Melting Slicks
Joined: Jan 2005
Posts: 2,326
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From: louisville "derby city" kentucky
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
The cheapest route if you are concerned is to convert to a C5 rear. Their cores are 1/4 the price of a 2006+ core. Plus you have to buy the trans adapter.
If you convert to a C5 rear, you can sell your working C6 rear as a core to someone and not throw that money away like you would be doing if you cracked the case.
Seems mostly manuals are breaking though, mine broke on my 301'st run, though some guys have broken on the street. Wheel hopping is definitely a bad thing.
Here's a lot of info on the conversion if you are interested. Sparo2 is pretty much an expert now, he's done a bunch.
http://forums.corvetteforum.com/c6-t...-write-up.html
If you convert to a C5 rear, you can sell your working C6 rear as a core to someone and not throw that money away like you would be doing if you cracked the case.
Seems mostly manuals are breaking though, mine broke on my 301'st run, though some guys have broken on the street. Wheel hopping is definitely a bad thing.
Here's a lot of info on the conversion if you are interested. Sparo2 is pretty much an expert now, he's done a bunch.
http://forums.corvetteforum.com/c6-t...-write-up.html
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Le Mans Master
Joined: Aug 2004
Posts: 5,259
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From: Monroe Township New Jersey
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16
St. Jude donor in memory of jpee '14
The key as Marc said is to watch the water box & etc. I would add some insurance by replacing the shocks with bilsteins to be on the safe side. Dennis car leaves a bit harder than mine and has many many more faster passes. Wheel hop will destroy the rear as long as you control it you will be fine.
Good lucK and enjoy the 3.73 gears
Melting Slicks
Joined: Sep 2008
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My mods are listed in my sign. I did a poll a while back. I hope this sheds a little light on this.
http://forums.corvetteforum.com/c6-t...ferential.html
http://forums.corvetteforum.com/c6-t...ferential.html
Tech Contributor
Joined: Mar 2003
Posts: 12,094
Likes: 197
From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
I have a C5 diff in my car with R-compound tires for 4 years now and it handles anything I could throw at it high n/a power, boost, and nitrous.
Its durable and cheap. I think a new core is about 700 or so.
Its durable and cheap. I think a new core is about 700 or so.