I did this work back in January of this year (2014) then originally posted this on "tahoe yukon forum .com" back in February. I'm sharing here to get the word out that this kind of swap can be done and to pay tribute to the community here that helped me by kindly sharing their knowledge. By doing this work to my Tahoe I'm standing on the shoulders of giants...the same giants that put together the excellent knowledge on here, like the Official A4 to M6 Thread. Based on that thread, I planned this swap before I even owned the Tahoe, which I bought in August of 2013. I have a custom short-throw shifter and shifter handle that I'll either follow up on this thread or post separate threads about soon.

I will never have a daily driver that is an automatic if I can help it. It is my strongly held personal belief that this mod is a requirement as it fixes the biggest flaw of the NBS Tahoe: an automatic transmission. I did an auto-to-manual swap on my last vehicle (2003 Toyota Tacoma) so this is just a natural progression of making this Tahoe to be MY TAHOE.

With that said, I have to pay credit to where it's due. I'm standing on the shoulders of giants by doing this to my Tahoe because this conversion was not my original idea. The biggest reason I decided to buy a Tahoe is because of vanillagorilla's thread over at performancetrucksDOTnet that covers his Official A4 to M6 (T-56) Thread . vanillagorilla's thread covers all the necessary information, so I'm not going to go too far into the build detail. My aim is to show that the conversion is possible in an NBS Tahoe, show what it costs, then point out what I had to do that wasn't a direct bolt-in.

Parts

• $2300 T56 GM/LS1 rebuilt to withstand 750 foot pounds of torque
• $220 lightly used LS flywheel/clutch/pressure plate
• $160 abused & used LS T56 Bell Housing
• $35 Arp-330-2802 Flywheel Bolts
• $24 Arp-134-2201 Pressure Plate Bolts
• $25 Grade 10.9 M10x1.5x40 Fasteners
  For Bell housing to engine & transmission to bell housing
  From McMaster
• $176 Slave/Master/Hydraulic-Line CC649034 (Rockauto)
• $4 Brake pedal pad 15706041 (Rockauto)
• $47 Shipping (Rockauto)
• $18 Pilot Bearing (O'Reilly Auto Parts)
• $135 used crossmember from a 2003 Silverado with manual transmission
• $75 used clutch pedtal from a Silverado
• $52 Throwout shim kit (TICK Performance)
• $300 HPTuners (used)
• $100 HPTuners credits for my single vehicle
• $130 Driveshaft shortening (1") and balancing
• $0 used t-shirt for prototype shifter boot
• $20 Genuine leather for shifter boot

My Process At A High Level
Items in red are not direct bolt-ins

• remove the old tranny/flywheel
• install the pilot bearing
• install the flywheel/clutch/pressure-plate onto the engine
• install the bell housing onto the engine
• remove the entire center console (temporarily)
• cut the hole in the floor for the shifter
• install the transmission onto the back of the bell housing
• cut the hole in the firewall for the clutch pedal
• install the clutch pedal and master cylinder and run the hydraulic line
• cut the brake pedal to be the size of a manual brake pedal
• buy or fabricate a shifter arm, then install
• buy or fabricate a short throw shifter, then install
• alter the center console to allow a spot for the shifter
• buy or make a shifter boot, then install
• reinstall the center console
• measure the driveshaft then have it shortened or lengthened then balanced
• install the driveshaft
• rewire the park/neutral switch to be in drive so that the speedometer and cruise work, and that the Tahoe will start
• wire up the reverse lockout into the brake pedal switch
• wire up the reverse lights
• correct the speedometer with HPTuner
• retune the throttle flollower with HPTuner so that the throttle falls faster and makes shifts smoother
• remove error codes due to the manual transmission being removed with HPTuner

Pros

• When I don't hammer the gas pedal and bang through the gears after every stop light I see an increase of 2MPG across the board
• IT'S FUN TO DRIVE THIS WAY
• You get to command your Tahoe when and how to shift. Since the 4L60e is compter controlled this means there's one less computer in control of my destiny. SCREW YOU SKYNET!!!
• The truck is instantly more responsive thanks to not having a torque converter any longer
• This was the way this truck should have come from the factory.

Cons

• There is a lot of work involved to make this happen. For me this was a labor of love, so it was just another fun mod to do to my Tahoe...others may see this differently.
• There's quite a bit of cost involved with this mod. If you don't need a new transmission and/or you're not sure you'll own your Tahoe for a long time then this mod is not for you.

This transmission shifted fine...but I strongly dislike automatic transmissions, so it's got to go:


Here she is, 750 foot pounds of torque handling beauty:


Here's the master cylinder, hydraulic line, and slave cylinder:


Here's the shifter before the installation of the short throw kit:


Before:


After:


Todo Items

• Finish tweaking the custom short throw shifter
• Tweak the custom shifter arm so that the shifter is in the sweet spot for my comfort
• Create a refined shifter boot in real leather
• Wire the clutch pedal to interrupt the cruise control
• Wire the clutch pedal to interrupt the starter when not depressed
• Ditch the stock 3.73 rear end gear and install a 4.10 gear - I've had 4.10 gears installed and with my tire size and the gearing of the T56 I'm running the final gear ratio is perfect for my use

Things I'd Do Differently If I Did It Again

• Use a TICK Clutch remote bleeder line - I've since added this and it make bleeding the clutch *much* easier
• Use a new bell housing. The used one I bought had three bolt holes stripped, so I had to ream them out and thread them to use M12X1.5 fasteners. With this added cost I saved less than $20, and bell housings cost $200 new.
• Budget for a stronger clutch because the weight of the Tahoe is a little too much for the clutch to last long term.

 

Here's a 3-4-5 pull then cruising and decellerating in 6th:

 

This is AWESOME.
Great job man, I'd love to do this to my Tahoe.

How much more work would it be in an 07 model?

 

Badass!!

Mike

 

Awesome swap. What was done to the trans to get it to handle 750 ft lb?

 

how long did the swap take you, once you started pulling everything apart? I'm thinking of doing the same with my 06 silverado.

 

if i ever bought a Tahoe/Sub, this has been the first on the mod list ever since i started entertaining the idea of selling my truck... except with an NV4500 for the 4x4

 

This thread is very inspiring. I am going to print it out and save it for when my tranny gets closer to dying. 192K miles so far.

Really appreciate you making this thread!

 

Thank you so much been searching for days for just a checklist on how to do this!!