C5 Auto Trans to Manual Trans Swap - "Lessons Learned" Part 1
07-18-2012, 10:49 PM
#1
Racer
Thread Starter
C5 Auto Trans to Manual Trans Swap - "Lessons Learned" Part 1
From some previous threads, most of you have gathered that after 14 years of driving my 1998 convertable around I've decided to swap out the original A4 automatic transmission for an MN6...
Although the project isn't completed yet sue to a snag in the rear wiring harness I chose, for those that are thinking of doing the same I've posted a few "Leassons Learned" that may (hopefully) help you avoid some headaches!
OBSERVATIONS:
All-in-all the swap is pretty straight forward - remove the rear suspension, remove exhaust (crossover pipe and cat-back mufflers), remove trans tunnel plate, and drop the differential / transmission / torque tube as one assembly, remove bellhousing and finally rear wire harness (you'll have to remove the battery and battery tray to get to the connectors that are on the inside of the right fender area).
Working about 3 - 4 hours a day, the above took only a few days. I discovered mice had made nests on top of both rear shock mounts, and under the battery tray itself. I also discovered my F45 shocks (Real Time Dampening) were completely flat and lifeless in the rear - all of 'em are being replaced with Z06 shocks from GM Parts House, which will require deletion of the RPO F45 Option from the BCM (more on that later!)
TIME SAVERS:
I bought all the parts from Corvette Recycling - MN6 trans and diff, shifter, pedals, torque tube, clutch, flywheel, pressure plate, etc. The parts were the most awesomely clean "used" parts I have ever seen! I only had to scrounge around for a few odds and ends elsewhere (shift ****, boot, etc.)
The clutch and brake pedals are no drama - the entire unit (i.e., dash support) DOES NOT need to come out! Just remove the plastic cover way underneath the steering column held in with two (2) plastic "Christmas tree" push-in fasteners and a round flat metal pushnut that grabs a tapered shaft that is molded into the magnesium casting. No need to tear up your dash - this cover is all you need to remove in order to get to the pedal hardware!
There is a cast relief along the top of the pedal housing that will allow you to insert a deep well socket to hold the hidden nut on one end and you can use a 13mm box wrench on the other end to loosen the bolt holding on the brake pedal. The insulation pad is die cut so you can pull a strip of it out of the relief to get the socket in, and there is also a cut-out that allows you to insert the box wrench - which helps.
Before you install the new (narrower) manual shift brake pedal after removing the auto brake pedal MAKE SURE you install the black stud plate (it has three captured bolts) in place that will be used to hold the stamped clutch pedal bracket. I didn't do this the first time and had to remove the brake pedal (again) after I went through all the trouble to install it the first time!
When removing the rear suspension, I sprayed the exposed ends of the black plastic "Cristmas tree" push-in fasteners with silicone spray. As a matter of fact I sprayed EVERY rubber suspension part and shock bushing with silicone spray. I love the stuff... However, it does seem to help the plastic fasteners pry out easier that are attached to the suspension cradle - there are a couple holding the rear brake lines and some more holding the wiring in place back there, MAKE SURE they're all popped out of place before you begin to lower anything!
The auto trans has a bearing in the front of the torque tube that will need to be supported during removal. The GM Service Manual specifies usage of two (2) M10-1.5mm x 55mm bolts. I made the mistake of buying these at a local hardware store only to find out the ENTIRE length of the shank needs to be threaded, as it will be screwed about 2" into the torque tube. The ones you'll most likely find at a chain hardware store seem to be threaded roughly 1/3 the shank length - these WON'T work! I improvised by buying pre-cut lengths of M10 X 1.5mm rod and adding two (2) nuts and a lockwasher at one end - tighten the nuts with the lockwasher between them, so you now have made the equivalent of a long threaded bolt that will do the job.
TIME WASTERS:
There were two insanely aggrevating "time wasters" that I encountered. The first was the little 7mm sheetmetal screw that holds the F45 shock absorber wire to a sheetmetal bracket on the frame rail near the top of the shock absorber. This is obscured by the rear tie rod enough so you can clearly see it, but can't remove it with a socket wrench (if you don't have the Real Time Dampening option, count your lucky stars!)
The bracket is too flimsy to yank the connector(s) off of without bending it all up, and as the screw is backed out with a socket wrench, it will "bottom out" the wrench against the tie rod, trapping both the socket wrench and the screw... I messed around with this for an hour - and ended up just backing off the four (4) 21mm nuts that hold the cradle to the frame about an inch, which opened up enough space to use the socket wrench to get the tiny 7mm sheetmetal screws off finally (there is one on each side).
With the auto trans I probably would have used the transmission support tool (J-42055) if I had to do it all over again - however the thing was pretty expensive! I ended up using a transmission jack on the front of the transmission and a floor jack under the differential in order to avoid crushing the transmission pan. Not the most ideal arrangement - the transmission wanted to "rock" to one side on the transmission jack due to an off-centered casting up front when the floor jack was lowered. So back and forth - lower one, lower the other. Lower one - lower the other. Better just to have everything balanced in the center using the right tools!
The final headache was removing the upper bellhousing bolts. You can see 'em - but you just can't get to 'em real well! Removing the "L" shaped rubber drain tube helps get access in one case, as does bending the rear wiring harness bracket. Try to get all the junk out of the way, and having some long and crazy angled 13mm wrenches would help here - the standard 6" combo wrench makes progress SLOWLY here, netting only 1/16th of a turn at a time.
Hopefully this wasn't too long - and may save you some headaches if you decide to swap out your automatic transmission for a manual unit. I'll post the rest as it unfolds!
Jeff
Although the project isn't completed yet sue to a snag in the rear wiring harness I chose, for those that are thinking of doing the same I've posted a few "Leassons Learned" that may (hopefully) help you avoid some headaches!
OBSERVATIONS:
All-in-all the swap is pretty straight forward - remove the rear suspension, remove exhaust (crossover pipe and cat-back mufflers), remove trans tunnel plate, and drop the differential / transmission / torque tube as one assembly, remove bellhousing and finally rear wire harness (you'll have to remove the battery and battery tray to get to the connectors that are on the inside of the right fender area).
Working about 3 - 4 hours a day, the above took only a few days. I discovered mice had made nests on top of both rear shock mounts, and under the battery tray itself. I also discovered my F45 shocks (Real Time Dampening) were completely flat and lifeless in the rear - all of 'em are being replaced with Z06 shocks from GM Parts House, which will require deletion of the RPO F45 Option from the BCM (more on that later!)
TIME SAVERS:
I bought all the parts from Corvette Recycling - MN6 trans and diff, shifter, pedals, torque tube, clutch, flywheel, pressure plate, etc. The parts were the most awesomely clean "used" parts I have ever seen! I only had to scrounge around for a few odds and ends elsewhere (shift ****, boot, etc.)
The clutch and brake pedals are no drama - the entire unit (i.e., dash support) DOES NOT need to come out! Just remove the plastic cover way underneath the steering column held in with two (2) plastic "Christmas tree" push-in fasteners and a round flat metal pushnut that grabs a tapered shaft that is molded into the magnesium casting. No need to tear up your dash - this cover is all you need to remove in order to get to the pedal hardware!
There is a cast relief along the top of the pedal housing that will allow you to insert a deep well socket to hold the hidden nut on one end and you can use a 13mm box wrench on the other end to loosen the bolt holding on the brake pedal. The insulation pad is die cut so you can pull a strip of it out of the relief to get the socket in, and there is also a cut-out that allows you to insert the box wrench - which helps.
Before you install the new (narrower) manual shift brake pedal after removing the auto brake pedal MAKE SURE you install the black stud plate (it has three captured bolts) in place that will be used to hold the stamped clutch pedal bracket. I didn't do this the first time and had to remove the brake pedal (again) after I went through all the trouble to install it the first time!
When removing the rear suspension, I sprayed the exposed ends of the black plastic "Cristmas tree" push-in fasteners with silicone spray. As a matter of fact I sprayed EVERY rubber suspension part and shock bushing with silicone spray. I love the stuff... However, it does seem to help the plastic fasteners pry out easier that are attached to the suspension cradle - there are a couple holding the rear brake lines and some more holding the wiring in place back there, MAKE SURE they're all popped out of place before you begin to lower anything!
The auto trans has a bearing in the front of the torque tube that will need to be supported during removal. The GM Service Manual specifies usage of two (2) M10-1.5mm x 55mm bolts. I made the mistake of buying these at a local hardware store only to find out the ENTIRE length of the shank needs to be threaded, as it will be screwed about 2" into the torque tube. The ones you'll most likely find at a chain hardware store seem to be threaded roughly 1/3 the shank length - these WON'T work! I improvised by buying pre-cut lengths of M10 X 1.5mm rod and adding two (2) nuts and a lockwasher at one end - tighten the nuts with the lockwasher between them, so you now have made the equivalent of a long threaded bolt that will do the job.
TIME WASTERS:
There were two insanely aggrevating "time wasters" that I encountered. The first was the little 7mm sheetmetal screw that holds the F45 shock absorber wire to a sheetmetal bracket on the frame rail near the top of the shock absorber. This is obscured by the rear tie rod enough so you can clearly see it, but can't remove it with a socket wrench (if you don't have the Real Time Dampening option, count your lucky stars!)
The bracket is too flimsy to yank the connector(s) off of without bending it all up, and as the screw is backed out with a socket wrench, it will "bottom out" the wrench against the tie rod, trapping both the socket wrench and the screw... I messed around with this for an hour - and ended up just backing off the four (4) 21mm nuts that hold the cradle to the frame about an inch, which opened up enough space to use the socket wrench to get the tiny 7mm sheetmetal screws off finally (there is one on each side).
With the auto trans I probably would have used the transmission support tool (J-42055) if I had to do it all over again - however the thing was pretty expensive! I ended up using a transmission jack on the front of the transmission and a floor jack under the differential in order to avoid crushing the transmission pan. Not the most ideal arrangement - the transmission wanted to "rock" to one side on the transmission jack due to an off-centered casting up front when the floor jack was lowered. So back and forth - lower one, lower the other. Lower one - lower the other. Better just to have everything balanced in the center using the right tools!
The final headache was removing the upper bellhousing bolts. You can see 'em - but you just can't get to 'em real well! Removing the "L" shaped rubber drain tube helps get access in one case, as does bending the rear wiring harness bracket. Try to get all the junk out of the way, and having some long and crazy angled 13mm wrenches would help here - the standard 6" combo wrench makes progress SLOWLY here, netting only 1/16th of a turn at a time.
Hopefully this wasn't too long - and may save you some headaches if you decide to swap out your automatic transmission for a manual unit. I'll post the rest as it unfolds!
Jeff
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00vetter (12-29-2016)
05-03-2014, 04:58 PM
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Location: western springs illinois
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From some previous threads, most of you have gathered that after 14 years of driving my 1998 convertable around I've decided to swap out the original A4 automatic transmission for an MN6...
Although the project isn't completed yet sue to a snag in the rear wiring harness I chose, for those that are thinking of doing the same I've posted a few "Leassons Learned" that may (hopefully) help you avoid some headaches!
OBSERVATIONS:
All-in-all the swap is pretty straight forward - remove the rear suspension, remove exhaust (crossover pipe and cat-back mufflers), remove trans tunnel plate, and drop the differential / transmission / torque tube as one assembly, remove bellhousing and finally rear wire harness (you'll have to remove the battery and battery tray to get to the connectors that are on the inside of the right fender area).
Working about 3 - 4 hours a day, the above took only a few days. I discovered mice had made nests on top of both rear shock mounts, and under the battery tray itself. I also discovered my F45 shocks (Real Time Dampening) were completely flat and lifeless in the rear - all of 'em are being replaced with Z06 shocks from GM Parts House, which will require deletion of the RPO F45 Option from the BCM (more on that later!)
TIME SAVERS:
I bought all the parts from Corvette Recycling - MN6 trans and diff, shifter, pedals, torque tube, clutch, flywheel, pressure plate, etc. The parts were the most awesomely clean "used" parts I have ever seen! I only had to scrounge around for a few odds and ends elsewhere (shift ****, boot, etc.)
The clutch and brake pedals are no drama - the entire unit (i.e., dash support) DOES NOT need to come out! Just remove the plastic cover way underneath the steering column held in with two (2) plastic "Christmas tree" push-in fasteners and a round flat metal pushnut that grabs a tapered shaft that is molded into the magnesium casting. No need to tear up your dash - this cover is all you need to remove in order to get to the pedal hardware!
There is a cast relief along the top of the pedal housing that will allow you to insert a deep well socket to hold the hidden nut on one end and you can use a 13mm box wrench on the other end to loosen the bolt holding on the brake pedal. The insulation pad is die cut so you can pull a strip of it out of the relief to get the socket in, and there is also a cut-out that allows you to insert the box wrench - which helps.
Before you install the new (narrower) manual shift brake pedal after removing the auto brake pedal MAKE SURE you install the black stud plate (it has three captured bolts) in place that will be used to hold the stamped clutch pedal bracket. I didn't do this the first time and had to remove the brake pedal (again) after I went through all the trouble to install it the first time!
When removing the rear suspension, I sprayed the exposed ends of the black plastic "Cristmas tree" push-in fasteners with silicone spray. As a matter of fact I sprayed EVERY rubber suspension part and shock bushing with silicone spray. I love the stuff... However, it does seem to help the plastic fasteners pry out easier that are attached to the suspension cradle - there are a couple holding the rear brake lines and some more holding the wiring in place back there, MAKE SURE they're all popped out of place before you begin to lower anything!
The auto trans has a bearing in the front of the torque tube that will need to be supported during removal. The GM Service Manual specifies usage of two (2) M10-1.5mm x 55mm bolts. I made the mistake of buying these at a local hardware store only to find out the ENTIRE length of the shank needs to be threaded, as it will be screwed about 2" into the torque tube. The ones you'll most likely find at a chain hardware store seem to be threaded roughly 1/3 the shank length - these WON'T work! I improvised by buying pre-cut lengths of M10 X 1.5mm rod and adding two (2) nuts and a lockwasher at one end - tighten the nuts with the lockwasher between them, so you now have made the equivalent of a long threaded bolt that will do the job.
TIME WASTERS:
There were two insanely aggrevating "time wasters" that I encountered. The first was the little 7mm sheetmetal screw that holds the F45 shock absorber wire to a sheetmetal bracket on the frame rail near the top of the shock absorber. This is obscured by the rear tie rod enough so you can clearly see it, but can't remove it with a socket wrench (if you don't have the Real Time Dampening option, count your lucky stars!)
The bracket is too flimsy to yank the connector(s) off of without bending it all up, and as the screw is backed out with a socket wrench, it will "bottom out" the wrench against the tie rod, trapping both the socket wrench and the screw... I messed around with this for an hour - and ended up just backing off the four (4) 21mm nuts that hold the cradle to the frame about an inch, which opened up enough space to use the socket wrench to get the tiny 7mm sheetmetal screws off finally (there is one on each side).
With the auto trans I probably would have used the transmission support tool (J-42055) if I had to do it all over again - however the thing was pretty expensive! I ended up using a transmission jack on the front of the transmission and a floor jack under the differential in order to avoid crushing the transmission pan. Not the most ideal arrangement - the transmission wanted to "rock" to one side on the transmission jack due to an off-centered casting up front when the floor jack was lowered. So back and forth - lower one, lower the other. Lower one - lower the other. Better just to have everything balanced in the center using the right tools!
The final headache was removing the upper bellhousing bolts. You can see 'em - but you just can't get to 'em real well! Removing the "L" shaped rubber drain tube helps get access in one case, as does bending the rear wiring harness bracket. Try to get all the junk out of the way, and having some long and crazy angled 13mm wrenches would help here - the standard 6" combo wrench makes progress SLOWLY here, netting only 1/16th of a turn at a time.
Hopefully this wasn't too long - and may save you some headaches if you decide to swap out your automatic transmission for a manual unit. I'll post the rest as it unfolds!
Jeff
Although the project isn't completed yet sue to a snag in the rear wiring harness I chose, for those that are thinking of doing the same I've posted a few "Leassons Learned" that may (hopefully) help you avoid some headaches!
OBSERVATIONS:
All-in-all the swap is pretty straight forward - remove the rear suspension, remove exhaust (crossover pipe and cat-back mufflers), remove trans tunnel plate, and drop the differential / transmission / torque tube as one assembly, remove bellhousing and finally rear wire harness (you'll have to remove the battery and battery tray to get to the connectors that are on the inside of the right fender area).
Working about 3 - 4 hours a day, the above took only a few days. I discovered mice had made nests on top of both rear shock mounts, and under the battery tray itself. I also discovered my F45 shocks (Real Time Dampening) were completely flat and lifeless in the rear - all of 'em are being replaced with Z06 shocks from GM Parts House, which will require deletion of the RPO F45 Option from the BCM (more on that later!)
TIME SAVERS:
I bought all the parts from Corvette Recycling - MN6 trans and diff, shifter, pedals, torque tube, clutch, flywheel, pressure plate, etc. The parts were the most awesomely clean "used" parts I have ever seen! I only had to scrounge around for a few odds and ends elsewhere (shift ****, boot, etc.)
The clutch and brake pedals are no drama - the entire unit (i.e., dash support) DOES NOT need to come out! Just remove the plastic cover way underneath the steering column held in with two (2) plastic "Christmas tree" push-in fasteners and a round flat metal pushnut that grabs a tapered shaft that is molded into the magnesium casting. No need to tear up your dash - this cover is all you need to remove in order to get to the pedal hardware!
There is a cast relief along the top of the pedal housing that will allow you to insert a deep well socket to hold the hidden nut on one end and you can use a 13mm box wrench on the other end to loosen the bolt holding on the brake pedal. The insulation pad is die cut so you can pull a strip of it out of the relief to get the socket in, and there is also a cut-out that allows you to insert the box wrench - which helps.
Before you install the new (narrower) manual shift brake pedal after removing the auto brake pedal MAKE SURE you install the black stud plate (it has three captured bolts) in place that will be used to hold the stamped clutch pedal bracket. I didn't do this the first time and had to remove the brake pedal (again) after I went through all the trouble to install it the first time!
When removing the rear suspension, I sprayed the exposed ends of the black plastic "Cristmas tree" push-in fasteners with silicone spray. As a matter of fact I sprayed EVERY rubber suspension part and shock bushing with silicone spray. I love the stuff... However, it does seem to help the plastic fasteners pry out easier that are attached to the suspension cradle - there are a couple holding the rear brake lines and some more holding the wiring in place back there, MAKE SURE they're all popped out of place before you begin to lower anything!
The auto trans has a bearing in the front of the torque tube that will need to be supported during removal. The GM Service Manual specifies usage of two (2) M10-1.5mm x 55mm bolts. I made the mistake of buying these at a local hardware store only to find out the ENTIRE length of the shank needs to be threaded, as it will be screwed about 2" into the torque tube. The ones you'll most likely find at a chain hardware store seem to be threaded roughly 1/3 the shank length - these WON'T work! I improvised by buying pre-cut lengths of M10 X 1.5mm rod and adding two (2) nuts and a lockwasher at one end - tighten the nuts with the lockwasher between them, so you now have made the equivalent of a long threaded bolt that will do the job.
TIME WASTERS:
There were two insanely aggrevating "time wasters" that I encountered. The first was the little 7mm sheetmetal screw that holds the F45 shock absorber wire to a sheetmetal bracket on the frame rail near the top of the shock absorber. This is obscured by the rear tie rod enough so you can clearly see it, but can't remove it with a socket wrench (if you don't have the Real Time Dampening option, count your lucky stars!)
The bracket is too flimsy to yank the connector(s) off of without bending it all up, and as the screw is backed out with a socket wrench, it will "bottom out" the wrench against the tie rod, trapping both the socket wrench and the screw... I messed around with this for an hour - and ended up just backing off the four (4) 21mm nuts that hold the cradle to the frame about an inch, which opened up enough space to use the socket wrench to get the tiny 7mm sheetmetal screws off finally (there is one on each side).
With the auto trans I probably would have used the transmission support tool (J-42055) if I had to do it all over again - however the thing was pretty expensive! I ended up using a transmission jack on the front of the transmission and a floor jack under the differential in order to avoid crushing the transmission pan. Not the most ideal arrangement - the transmission wanted to "rock" to one side on the transmission jack due to an off-centered casting up front when the floor jack was lowered. So back and forth - lower one, lower the other. Lower one - lower the other. Better just to have everything balanced in the center using the right tools!
The final headache was removing the upper bellhousing bolts. You can see 'em - but you just can't get to 'em real well! Removing the "L" shaped rubber drain tube helps get access in one case, as does bending the rear wiring harness bracket. Try to get all the junk out of the way, and having some long and crazy angled 13mm wrenches would help here - the standard 6" combo wrench makes progress SLOWLY here, netting only 1/16th of a turn at a time.
Hopefully this wasn't too long - and may save you some headaches if you decide to swap out your automatic transmission for a manual unit. I'll post the rest as it unfolds!
Jeff
But what do you think about upgrading a C5 auto to a C6 Paddle shift?
05-04-2014, 08:11 AM
#4
Melting Slicks
Unless you put in the entire rear cradle, tranny and diff. The C6 had a one inch longer wheelbase because the transmission was longer.
Do a search, this topic has been covered pretty well.
Add in the fact that you need to upgrade the software and tranny control, and the fact that while it had paddle shifters on the column, it didn't really shift all that well, makes it more effort than it is worth.
05-04-2014, 05:40 PM
#5
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It won't fit... At least it's not an easy bolt in job.
Unless you put in the entire rear cradle, tranny and diff. The C6 had a one inch longer wheelbase because the transmission was longer.
Do a search, this topic has been covered pretty well.
Add in the fact that you need to upgrade the software and tranny control, and the fact that while it had paddle shifters on the column, it didn't really shift all that well, makes it more effort than it is worth.
Unless you put in the entire rear cradle, tranny and diff. The C6 had a one inch longer wheelbase because the transmission was longer.
Do a search, this topic has been covered pretty well.
Add in the fact that you need to upgrade the software and tranny control, and the fact that while it had paddle shifters on the column, it didn't really shift all that well, makes it more effort than it is worth.
Thanks
