Pumba

Last week I brought my C5 Z06 home after the guys at RPM Transmission completed a major transformation of my driveline. Rodney, TJ, Wes, Guffey, and Kirt spent two plus days removing my C5 aluminum driveshaft and rubber couplers, my C6 MN6 T-56 Tremec trans, and my C5 Z06 - Quaife equipped 4.10:1 differential.

In their place, they installed a Pfadt Racing carbon-fiber driveshaft, a Liberty Gear custom ratio C6 ZR1 T-6060 transmission, and one of their Quaife-equipped C6 ZR1 differential assemblies, with micro-polished 3.42:1 gears, a C6 rear crossmember with Pfadt Racing offset differential mounts, and modifying my exhaust to clear the new C6 crossmember.



The first order of business once I arrived was to move my Z06 onto one of RPM's hoists:






While all the C5 components were being removed, Kirt started the build of the C6 ZR1 differential. The following pictures show the strengthening that GM engineers put into the ZR1's differential case compared to a C5 Z06 case.


C6 ZR1 case - top view and its massive strengthening webs:





C6 ZR1 Case - Bottom View





Also, the C6 ZR1 differential has an 8.75 inch ring and pinion set versus the C5's 7.75 inch set.




Kirt had the internal components of the Quaife, the ring and pinion, and the output shafts waiting on his work bench when I arrived.


Below are the micro-polished internal components:




Here are the micropolished 3.42:1 ring and pinion set and the output shafts:





Next are shown the two halves of the Quaife case, followed by the build sequence of its internal parts:


















Here is the completed Quaife





Followed by the Quaife with the ring gear and output shaft installed








Next, came the installation of the pinion support and the pinion gear:








RPM feels that the ZR1 pinion support casting is made of a different - superior material than other C5 and C6 pinion supports.



After the pinion support and gear were installed, Kirt literally removed and installed the Quaife, with the ring gear over a dozen times in order to gear the backlash and pre-load not just to within GM's specifications, but to the sweet spot that brings long life and quiet operation.



While Kirt was working on the diff, Guffey was working on my new Pfadt Racing carbon-fiber driveshaft.

Here is a picture of a standard C5 aluminum driveshaft with its rubber couplers:







The next two pictures show the Pfadt carbon-fiber driveshaft. Until you pick one of these driveshafts up, you cannot believe how light they are:













Guffey also installed the Pfadt 17-4PH Stainless Steel couplers that replace the rubber couplers used by the C5 and C6 Corvettes:










He also prepared my Liberty Gear Tremec T-6060 trans for installation:








When you convert a C5 to the C6 ZR1 trans and diff, you must also replace the C5 rear crossmember with a C6 rear crossmember:










Aaron Phaft also makes the offset diff mounts that are needed to complete the conversion. If you do not have coilover shockabsorbers, you will also need C6 rear lower control arms.



Rodney also plumbed my trans so the headset is cooled by the internal T-6060 pump and the remainder of the trans is cooled by the L.G. pump.



The RPM team also modified by Corsa mufflers and pipes so they would clear the new C6 ZR1 differential and rear crossmember. As a final touch, Kirt perfectly aligned my tail pipes.

During the final stages of the installation I asked TJ if RPM had ever installed this family of ZR1 and Pfadt components in a C5 before. His answer was that this was the first time they had installed all of them in a C5.

Driveability and shiftability of the T-6060 trans is vastly superior to the T-56 trans. Also, the diff makes no noises. Kirt hit the sweet spot again.

My thanks goes out to Rodney, TJ, Kirt, Guffey, Wes, and the entire crew at RPM for a superb job.

-

AverageVetteNut

wow... very impressive and detailed report

Congrats and that's something I never would've thought you could do... that is, replace the rear crossmember like that. Very neat indeed.

Good luck with it!

Racer Buzz

What other gear ratios are available for the ZR1 diff? 3:70, 3:90?

mgarfias

I sure hope that those fasteners in the pix weren't torqued or were replaced. Knowing pfadt though, I kinda doubt it.

Pumba

Somewhere on the Forum I read that, I believe it's Vette Doctors, has other gears sets available for the 8.75 inch ring and pinion used in the ZR1 and Z06 differentials.

Pumba

During the entire conversion process I was busy walking around RPM's shop taking pictures. These pictures were during Guffey's buildup of the driveshaft. He had not completed the build, or the torquing of the fasteners.

B505

Wow, that is really freakin cool. I've never seen a Quaife in pieces like that! Thanks for the pics!

CHJ In Virginia

Great write up and set of pictures. Thanks for posting the report on that bullett proof driveline !

Pumba

The RPM crew was very professional during the installation of the new C6 rear crossmember. They even drilled it so the GM clips that retain the wiring and brake lines could be used with the new crossmember.

Pumba

Thanks !

I neglected to mention that my Z06 is also equipped with a Fidanza dual-disc clutch. No muss - no fuss - no chatter - it holds up to 925 lb-ft of torque and it's a pleasure to drive.

froggy47

Nice setup.

Pumba

Thanks !