A4 to MN6 Swap = Lessons Learned!
08-15-2012, 02:27 PM
#1
Racer
Thread Starter
A4 to MN6 Swap = Lessons Learned!
It had a few "twists and turns" - but overall converting your C5 from an automatic transmission to a stick really isn't all that hard...
I'll keep things brief - and highlight what I found:
1) Pedals: Don't remove the whole dash support bracket, nor do you need to tear up your dash. Remove just the kick panel (one push nut and two plastic push-in fasteners) only. The pedals come out individually. Just make sure to install the stud plate that holds the clutch pedal bracket to the rest of the assembly BEFORE putting the new brake pedal in place, otherwise you'll have to take the brake pedal back off to get it in!
2) Clutch Master Cylinder: Drilling the hole in the firewall is no big deal; GM made it easy by molding a dimple on the "engine side" of the fiberglass! I did all kinds of measuring and scribing to determine the centerline of the hole - which was totally unecessary... just drill a small pilot hole in the center of the dimple, and use a hole saw to cut from the inside of the vehicle.
3) Clutch Neutral Safety Switch: For initial test purposes follow the yellow and purple wires from the neutral safety switch on the old automatic transmission to where they plug in to the connector by the battery tray. Open the connector and install a jumper (small bent piece of wire) to connect the two sockets in the female side of the connector that contain the yellow and purple wires (when you install the manual transmission torque tube harness, there won't be any wires in the male side of the connector to make this connection!) This will at least allow you to start the car initially - but defeats the "safety" aspect of the circuit. To do it right, splice in your clutch switch to these same wires and remove the jumper!
4) Brake Lines: Do NOT disconnect the brake lines! You don't need to, although some write-ups say you do... just push out the half dozen black plastic push-in fasteners in the rear suspension cradle and move the brake lines and wires out of the way as you lower the trans / diff / torque tube assy out of the vehicle.
5) Wiring Harness: This BY FAR was my greatest headache and time waster! Find the exact harness you need from your same year and with the same options - pay attention to mid-year engineering changes that may screw you up (for example, in mid-1998 the EBCM was moved from the rear to the front). I can't tell you how many hours I spent stripping out the F45 wiring from the auto trans bundle, and splicing it into the manual wiring. Argh!
6) Bell Housing: I read somewhere the auto bellhousing would work. It didn't (not at least with the LS7 clutch, pressure plate and flywheel set up I used) - and I tried everything! Too bad, because it's a nice one piece design with a big access window on the bottom covered by a rubber plug. Get the two-piece manual part and save yourself some headaches!
7) Input Shaft Alignment: There is a lot of talk about how critical this is - but it can be done fairly easily if you didn't take any careful measurements when you first removed everything! Initially guide the driveline assy into place and adjust to make sure the torque tube is level at both ends with respect to flat part of the transmission tunnel (the flange the tunnel cover screws go into). Rotate the flywheel in minute increments until the splines mesh; otherwise you aren't going anywhere! DO NOT try to use the torque tube bolts to pull everything into place until once you've got maybe 1/4" to 1/2" to finally go at the very end - the aluminum bellhousing threads WILL strip out and cause you huge pain and suffering otherwise! Use a giant c-clamp to pull the torque tube up to the bellhousing slowly, and measure the clearance on the bottom of the front torque tube flange and the top part and side to side - adjust the height and angle of the differential to make sure that "gap" up front is unform all around - do NOT try to force anything to fit... Go slowly and carefully and only use the torque tube bolts to snug it all together at the very end when everything aligned and almost completely togther!
8) F45 Real Time Dampening: I found out my 14-year old shocks were completely flat dead when I removed the rear suspension. I went with the C6 ZO6 shocks from GM Parts House - and defeated the error messages by plugging a ceramic 10 ohm resistor into the empty female wiring socket, putting a small Ziploc bag over it (upside down), and taping everything up! The resistors were something like $2.19 for a pack of two... Best 4 bucks I've ever spent in my life!
9) Conclusion and Future Mods: As someone here put it, it felt like a I had a brand new car all over again! Downshifting into corners is a blast, and the "new" suspension (I also had added ZR1 sway bars and drilled and slotted rotors) gives the car a much better handling feel... What's next? For starters a 3.90 R&P, a B&B PRT exhaust, and an LS6 intake manifold...
10) Many thanks to: Colton at Corvette Recycling, Marc at Vette Nuts, DDario for the A4 to MN6 write-up (I'll post the link when I find it again?!!) Chaplain for the freebie (I still have a package to send you!) and as always Gene at GM Parts House!
I'll post some pics when I find my camera - if anyone needs any specific info before doing this swap, please let me know! See you on Woodward this weekend
Jeff
I'll keep things brief - and highlight what I found:
1) Pedals: Don't remove the whole dash support bracket, nor do you need to tear up your dash. Remove just the kick panel (one push nut and two plastic push-in fasteners) only. The pedals come out individually. Just make sure to install the stud plate that holds the clutch pedal bracket to the rest of the assembly BEFORE putting the new brake pedal in place, otherwise you'll have to take the brake pedal back off to get it in!
2) Clutch Master Cylinder: Drilling the hole in the firewall is no big deal; GM made it easy by molding a dimple on the "engine side" of the fiberglass! I did all kinds of measuring and scribing to determine the centerline of the hole - which was totally unecessary... just drill a small pilot hole in the center of the dimple, and use a hole saw to cut from the inside of the vehicle.
3) Clutch Neutral Safety Switch: For initial test purposes follow the yellow and purple wires from the neutral safety switch on the old automatic transmission to where they plug in to the connector by the battery tray. Open the connector and install a jumper (small bent piece of wire) to connect the two sockets in the female side of the connector that contain the yellow and purple wires (when you install the manual transmission torque tube harness, there won't be any wires in the male side of the connector to make this connection!) This will at least allow you to start the car initially - but defeats the "safety" aspect of the circuit. To do it right, splice in your clutch switch to these same wires and remove the jumper!
4) Brake Lines: Do NOT disconnect the brake lines! You don't need to, although some write-ups say you do... just push out the half dozen black plastic push-in fasteners in the rear suspension cradle and move the brake lines and wires out of the way as you lower the trans / diff / torque tube assy out of the vehicle.
5) Wiring Harness: This BY FAR was my greatest headache and time waster! Find the exact harness you need from your same year and with the same options - pay attention to mid-year engineering changes that may screw you up (for example, in mid-1998 the EBCM was moved from the rear to the front). I can't tell you how many hours I spent stripping out the F45 wiring from the auto trans bundle, and splicing it into the manual wiring. Argh!
6) Bell Housing: I read somewhere the auto bellhousing would work. It didn't (not at least with the LS7 clutch, pressure plate and flywheel set up I used) - and I tried everything! Too bad, because it's a nice one piece design with a big access window on the bottom covered by a rubber plug. Get the two-piece manual part and save yourself some headaches!
7) Input Shaft Alignment: There is a lot of talk about how critical this is - but it can be done fairly easily if you didn't take any careful measurements when you first removed everything! Initially guide the driveline assy into place and adjust to make sure the torque tube is level at both ends with respect to flat part of the transmission tunnel (the flange the tunnel cover screws go into). Rotate the flywheel in minute increments until the splines mesh; otherwise you aren't going anywhere! DO NOT try to use the torque tube bolts to pull everything into place until once you've got maybe 1/4" to 1/2" to finally go at the very end - the aluminum bellhousing threads WILL strip out and cause you huge pain and suffering otherwise! Use a giant c-clamp to pull the torque tube up to the bellhousing slowly, and measure the clearance on the bottom of the front torque tube flange and the top part and side to side - adjust the height and angle of the differential to make sure that "gap" up front is unform all around - do NOT try to force anything to fit... Go slowly and carefully and only use the torque tube bolts to snug it all together at the very end when everything aligned and almost completely togther!
8) F45 Real Time Dampening: I found out my 14-year old shocks were completely flat dead when I removed the rear suspension. I went with the C6 ZO6 shocks from GM Parts House - and defeated the error messages by plugging a ceramic 10 ohm resistor into the empty female wiring socket, putting a small Ziploc bag over it (upside down), and taping everything up! The resistors were something like $2.19 for a pack of two... Best 4 bucks I've ever spent in my life!
9) Conclusion and Future Mods: As someone here put it, it felt like a I had a brand new car all over again! Downshifting into corners is a blast, and the "new" suspension (I also had added ZR1 sway bars and drilled and slotted rotors) gives the car a much better handling feel... What's next? For starters a 3.90 R&P, a B&B PRT exhaust, and an LS6 intake manifold...
10) Many thanks to: Colton at Corvette Recycling, Marc at Vette Nuts, DDario for the A4 to MN6 write-up (I'll post the link when I find it again?!!) Chaplain for the freebie (I still have a package to send you!) and as always Gene at GM Parts House!
I'll post some pics when I find my camera - if anyone needs any specific info before doing this swap, please let me know! See you on Woodward this weekend
Jeff
Last edited by kalayaan12; 08-15-2012 at 03:29 PM.
08-15-2012, 09:42 PM
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Member Since: Feb 2012
Location: Acworth Georgia
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Awesome achievement man, that sounds like a nice project with a huge payoff! Nothing beats having complete control of your powerband while running through the twisties!