1998 A4 differential replacement
Thread Starter
Instructor
Joined: May 2002
Posts: 136
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From: Perkvl PA
1998 A4 differential replacement
Is there a difference between the differential from a A4 vs 6 speed.
Why I ask? I bought a complete 3.15 unit and the mechanic who in installing it says it's for a 6speed and won't work with an automatic.
Why I ask? I bought a complete 3.15 unit and the mechanic who in installing it says it's for a 6speed and won't work with an automatic.
Pro
Joined: Sep 2003
Posts: 731
Likes: 0
From: Calgary Alberta
Re: 1998 A4 differential replacement (jrburb)
The carrier case between the 3.15 and up (3.42, 3.73, etc.) are all the same six speed or A4. The only carrier that is different is the 2.73. The 2.73 cases aren't as well reinforced.
Any of these C5 corvette differentials (Getrag) will work for your 98. If your mechanic doesn't know that, I suggest finding one who knows Corvette's. This will at least give you some peace of mind.
Any of these C5 corvette differentials (Getrag) will work for your 98. If your mechanic doesn't know that, I suggest finding one who knows Corvette's. This will at least give you some peace of mind.
Team Owner
Joined: Aug 2003
Posts: 38,314
Likes: 35
Re: 1998 A4 differential replacement (jrburb)
Is there a difference between the differential from a A4 vs 6 speed.
Why I ask? I bought a complete 3.15 unit and the mechanic who in installing it says it's for a 6speed and won't work with an automatic.
Why I ask? I bought a complete 3.15 unit and the mechanic who in installing it says it's for a 6speed and won't work with an automatic.
[Modified by EB20003, 8:13 PM 2/27/2004]
Thread Starter
Instructor
Joined: May 2002
Posts: 136
Likes: 2
From: Perkvl PA
Re: 1998 A4 differential replacement (hightest)
The mechanic said the face place on the differential in the car where it mates to the transmission is different. the current unit is the original 2.73's. The mechanis knows vette he builds race units for T1 class, but they are all 6 speeds.
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 179
From: S.W. Ohio. . . . . . NRA Life Member
Re: 1998 A4 differential replacement (jrburb)
the face plate is called a "seal plate". It is a 6" round disk that's removeable from the A4 diff and can be re-used on any C5 differential.
Depending on the cars original mileage; you might want to replace the two seals that are located on the seal plate. The part numbers fior these seals are located on this page:
http://mikemercury.home.att.net/342.htm
here is a pic of the carrier with the seal plate still installed:
Again; the plate is a seperate piece that can be removed and ported-over to any other C5 carrier.
[Modified by Mike Mercury, 10:46 PM 2/27/2004]
Depending on the cars original mileage; you might want to replace the two seals that are located on the seal plate. The part numbers fior these seals are located on this page:
http://mikemercury.home.att.net/342.htm
here is a pic of the carrier with the seal plate still installed:
Again; the plate is a seperate piece that can be removed and ported-over to any other C5 carrier.
[Modified by Mike Mercury, 10:46 PM 2/27/2004]
Team Owner
Joined: Aug 2003
Posts: 38,314
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Re: 1998 A4 differential replacement (jrburb)
Can he swap the faceplates?
Oops, I guess so. Mike would know.
I was also reading Mike V's write up where he says;
"To remove the differential plate, thats the plate that goes between the trans and the differential, use a large wide blade screw driver thru the center hole. Insert at an angle between the plate and the differential far enough so that when you turn it you are touching the plate and not the seal. Turn the screwdriver at 3 or 4 different areas to pop out the plate"
I too will be doing this swap in the future and am trying to learn as much as I can between now and then.
[Modified by EB20003, 9:55 PM 2/27/2004]
Burning Brakes
Joined: Aug 2002
Posts: 1,090
Likes: 8
From: Indianapolis Indiana
Re: 1998 A4 differential replacement (jrburb)
As the replies above suggest your mechanic needs a little more knowledge. Auto's come with 2.73s and 3.15s, 6-spds are 3.42s. They are I believe interchangable. I'm having 4.10s built for my 2000 auto. When the 3.15s come out of it I will have it rebuilt and put in my 2001 6spd. I will then keep the 3.42 from my 2001 in case I ever sell either car and want to pull the 4.10s for another.
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Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 179
From: S.W. Ohio. . . . . . NRA Life Member
Re: 1998 A4 differential replacement (EB20003)
I used a small pry-bar... similar to the one pictured here:
the pic makes the pry-bar look larger than it really is.
Going in from the center seal area - placing the pry bar between the seal plate and the carriers front casting face.
Just a little at a time as you move the pry bar around the circumference.
Re-installation has cause some a problem. Mainly; the outer "O" ring can get dislodged from the small slot in the plated outer edge. Placing a thin amount of diff fluid on the carriers "lip" surface (where the plates "O" ring makes contact) allows it to go in much easier.
Good luck and keep up posted.
[Modified by Mike Mercury, 10:43 AM 2/28/2004]
the pic makes the pry-bar look larger than it really is.
Going in from the center seal area - placing the pry bar between the seal plate and the carriers front casting face.
Just a little at a time as you move the pry bar around the circumference.
Re-installation has cause some a problem. Mainly; the outer "O" ring can get dislodged from the small slot in the plated outer edge. Placing a thin amount of diff fluid on the carriers "lip" surface (where the plates "O" ring makes contact) allows it to go in much easier.
Good luck and keep up posted.
[Modified by Mike Mercury, 10:43 AM 2/28/2004]
