C5 ZO6 Rear Diff ???
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Joined: Dec 2006
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From: Lufkin TX
C5 ZO6 Rear Diff ???
Any one Know what it takes to put a ZO6 rear diff in a 98 A4 car? Doing a tranny and want to go with a 342 gear? What are the diffrence between the two? Is it worth it? Did a Search and only post was a c6 zo6 diff. Any input would be very helpfull
Drifting
Joined: Jan 2004
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From: Alamosa CO
Should bolt right in. IIRC, you might need to get the PCM adjusted to calibrate the speedo since it has an auto trans, but other than that you should be good to go.
Safety Car
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From: You can't get there from here NJ
St. Jude Donor '08-'09
Just had it done today at ECS. 3.42's in my A4 from the stock 2.73's. I have to break in the gears before I can have fun with them, but I have driven C5 A4s with this rear, and the difference is HUGE.Performance is way better.Unless you have a lift, and all the tools, it is not something you want to do yourself. ECS did it with a tune in several hours. You need a tune to reset everything properly, and if you haven't gotten one, it is worth it. You can PM me if you have any questions.
Le Mans Master
Joined: Feb 2001
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From: West "By God" Virginia
CI 7-8-9-10 Veteran
I will have a very low mile Z rear for sale soon. It bolts right up to an A4 rear, a great mod. You will have to have a tune for shift points. Pm me if interested...
Le Mans Master
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St. Jude Donor '17
Melting Slicks
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From: Fishin' Pole FL
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Burning Brakes
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From: St. Paul MN
I also have an A4 and I'm upgrading to the 3.42 or 3.73 set very soon. In addition I'm going with a minimum of a 3200 converter.
BTW you can pick up a brand new Z06 rear from gmpartsdirect.com for like $1k.
I'm also planning on performing the swap myself. If you have the right tools (tranny jack) it should be a pretty straight forward procedure. I plan on doing it on my garage floor armed with nothing more than jacks and jackstands! It's winter here so I have no reason to rush the process...so that helps some.
Last edited by verano29; Jan 10, 2008 at 06:11 PM.
Safety Car
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From: You can't get there from here NJ
St. Jude Donor '08-'09
3.42's are great for an A4. I have always been curious about why everyone wants to do a tc upgrade with gears. I drove a vette with 3.42's, and a 3200 tc, and I hated it. It was really sloppy. I just did a ZO6 3.42 install, with no tc, and it seems fine to me. A higher tc such as 2800, or 3200 will only increase the point at which you can launch the car at the track. Mike Mercury did a real nice writeup on using a GM ( truck?) tc which only was somewhere around 2000 if I remember correctly, and was very happy with the results. Unless you want to take the car to race it, I don't get why everyone seems to think you have to do a 2800, 3200, 3600, or something like that tc upgrade. That is unless you like it sloppy
Correct me if I'm wrong, but why else would you want a high tc except to launch at higher rpms at the track? For a DD, I don't see the need.
Correct me if I'm wrong, but why else would you want a high tc except to launch at higher rpms at the track? For a DD, I don't see the need.
Racer
Joined: Dec 2004
Posts: 455
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From: Clovis CA
3.42's are great for an A4. I have always been curious about why everyone wants to do a tc upgrade with gears. I drove a vette with 3.42's, and a 3200 tc, and I hated it. It was really sloppy. I just did a ZO6 3.42 install, with no tc, and it seems fine to me. A higher tc such as 2800, or 3200 will only increase the point at which you can launch the car at the track. Mike Mercury did a real nice writeup on using a GM ( truck?) tc which only was somewhere around 2000 if I remember correctly, and was very happy with the results. Unless you want to take the car to race it, I don't get why everyone seems to think you have to do a 2800, 3200, 3600, or something like that tc upgrade. That is unless you like it sloppy Correct me if I'm wrong, but why else would you want a high tc except to launch at higher rpms at the track? For a DD, I don't see the need.
Correct me if I'm wrong, but why else would you want a high tc except to launch at higher rpms at the track? For a DD, I don't see the need.it allows you to stay in or closer to the powerband constantly. just like lugging a stick in third gear going 25 or 30mph and then having to down shift to get into the power band, a converter helps make whatever gear (based on speed) work more effectively.
the ONLY drawback is mileage suffers.....but then who drives a vette for the great mileage??
Race Director
Joined: Mar 2005
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my 98 A4 with Z rear and vigilante 2800 stall isn't sloppy at all. the power is 'right there' all of the time. not just at the track. driving around town, you will barely notice the stall.....unless you jump on it!!
it allows you to stay in or closer to the powerband constantly. just like lugging a stick in third gear going 25 or 30mph and then having to down shift to get into the power band, a converter helps make whatever gear (based on speed) work more effectively.
the ONLY drawback is mileage suffers.....but then who drives a vette for the great mileage??
it allows you to stay in or closer to the powerband constantly. just like lugging a stick in third gear going 25 or 30mph and then having to down shift to get into the power band, a converter helps make whatever gear (based on speed) work more effectively.
the ONLY drawback is mileage suffers.....but then who drives a vette for the great mileage??
Racer
Joined: Dec 2004
Posts: 455
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From: Clovis CA
I also have an A4 and I'm upgrading to the 3.42 or 3.73 set very soon. In addition I'm going with a minimum of a 3200 converter.
BTW you can pick up a brand new Z06 rear from gmpartsdirect.com for like $1k.
I'm also planning on performing the swap myself. If you have the right tools (tranny jack) it should be a pretty straight forward procedure. I plan on doing it on my garage floor armed with nothing more than jacks and jackstands! It's winter here so I have no reason to rush the process...so that helps some.
) he did it in his garage, on the floor, without a tranny jack, in half a day.....by himself. easy! of course it's california out here so weather isn't so bad. you should be able to knock it out no problem...and you'll love it afterward!! it'll feel like a 50 shot out of the hole!we swapped out the headers and exhaust on his A4 '05 (he's selling it, since he got the MN6) in about two hours on Christmas Eve morning. it seems that most of the guys on this forum think that you have to have every imaginable tool available and it'll take three days to change a plug wire.
Racer
Joined: Dec 2004
Posts: 455
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From: Clovis CA
to be sure, the temps are a bit higher in regular driving during summertime too. full synthetic valvoline atf is what i use and the tranny is fine after three years with the stall.
Le Mans Master
Joined: Mar 2002
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St. Jude Donor '17
true, very true. that's why my buddy is getting rid of his A4 '05 and got the MN6.
to be sure, the temps are a bit higher in regular driving during summertime too. full synthetic valvoline atf is what i use and the tranny is fine after three years with the stall.
to be sure, the temps are a bit higher in regular driving during summertime too. full synthetic valvoline atf is what i use and the tranny is fine after three years with the stall.
Le Mans Master
Joined: May 2006
Posts: 7,856
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From: Hillsboro OR
I changed to a 3:42 with a 2800 Yank a few months ago. 
I could not believe the difference. 
The plate that is mentioned above is currently on your car. You will need to transfer it to the new gear box when you swap.
Go for it!
I could not believe the difference. The plate that is mentioned above is currently on your car. You will need to transfer it to the new gear box when you swap.
Go for it!
Le Mans Master
Joined: May 2006
Posts: 7,856
Likes: 242
From: Hillsboro OR
I also have an A4 and I'm upgrading to the 3.42 or 3.73 set very soon. In addition I'm going with a minimum of a 3200 converter.
BTW you can pick up a brand new Z06 rear from gmpartsdirect.com for like $1k.
I'm also planning on performing the swap myself. If you have the right tools (tranny jack) it should be a pretty straight forward procedure. I plan on doing it on my garage floor armed with nothing more than jacks and jackstands! It's winter here so I have no reason to rush the process...so that helps some.
It is a LOT of work. I (and two friends) did mine on a lift and it took a day and a half.
Race Director
Joined: Mar 2005
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That said, the first time I did it, it took me a LONG time, and it was a LOT of hard work.
Now I could do it in 3 hours though.
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Joined: Dec 2006
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From: Lufkin TX
Thanks for all the input guys. This car i bought was a repo and i practicly stole it. when I got the car the trans was slipin bad. It went a whole 2 miles before it wouldnt move. I was going to get a guy in town to rebuild the trany, but weighed the cost and opted for a stage 4 from FLT with Vigilante 3200. I new of the car before I got it. It has a big Texas Speed cam kit in an LS6,under drive pully,converter, lt headers,fast intake,and 78mm throtle body. I figured that I should also go with 342s to kick it up a notch. So after all the replys I purchased a ZO6 diff from Gene Cully at GM Parts w/Plate and seals after reading Mikes thread. Agian thanks for all the help.
