Bracing for Breakage (Prevention, that is!)Aside from the usual breed of parts destruction you might expect from an IRS-equipped vehicle (like axleshaft and CV joint breakage), some high-power C6 owners have found out the hard way that their Corvette's transaxle assembly itself can fail. Think of the physics of the situation: torque is naturally imparted to the diff under acceleration, which creates a separating force between the upper mating surfaces of the diff and transmission. Given an engine with enough horsepower, this torque could overwhelm the structure of the factory transaxle assembly, particularly on a hard shift. Imagine a twig snapping and you get the idea.
DynoTech Engineering Inc. has created a solution. The company's Differential Strut Kit is advertised as significantly increasing the strength of the differential and transmission assembly for high-performance use. According to DTE, this differential strut increases the overall strength and rigidity of the diff/trans assembly, and does so by diverting drivetrain stress to the strongest points of attachment on the C6 transaxle.
Follow along while we install DTE's Differential Strut Kit onto our C6's transaxle, readying ourselves for hard launches and shifts with reduced fears of breakage. While we're obviously doing the install with the transaxle out of the car, DTE says that this item can also be installed without transaxle removal (you just have to lower the rear subframe slightly to gain sufficient clearance).
...And the entire drivetrain of the vehicle (sans engine)! Here you're looking at the C6's rear-mounted transmission/differential assembly, and the rear aluminum subframe surrounding it. All of this must be removed to access and replace the clutch, and without a lift and a heavy-duty trans jack, it's absolutely impossible. Fortunately, we've got the tools to get the job done. So enough whining--let's just do it. | 
Regardless of whether you've got a stock cat-back exhaust or an aftermarket one, the H- or X-pipe will need to be removed. As with the factory system, our ARH X-pipe has a slip-fit connection with the overaxle pipes, so we take it off and leave the overaxle pipes hanging for now. Because their collectors hang in the way of the bellhousing, both ARH headers must be removed as well. (Check out "Solely Stainless, Totally Tubular," May '07, for a detailed install of this ARH system--read the article backwards and you'll get the gist of how to remove it.) If your vehicle has stock exhaust manifolds, they can stay bolted to the heads, but the cat pipes will have to come out. |
A whopping 36 8mm bolts hold the driveline tunnel closeout panel to the framerails of the C6. (Be sure to torque each and every one of them later, during reinstallation.) With this structural panel removed, we can see the aluminum driveshaft "torque" tube that couples the clutch bellhousing to the rear-mounted Tremec tranny. (FYI, GM calls the driveshaft tube a "driveline support assembly"--we like our nomenclature better.) | 
Inside the vehicle, we remove another aftermarket product installed in a previous issue: our B&M shifter. (See "Ethereal Rush," Mar. '07, for a guide on how to gain access to the shifter.) In addition to unbolting the shifter from its mount, the entire mount/linkage mechanism must come out, too. All three Torx head bolts you see need to be removed to do this, with the one in the bottom-right of the photo serving to clamp the mechanism to the shift rod that leads back to the transmission. Also take note that we've inserted a small machine screw into a hole at the front of the mechanism. This holds the mechanism in the neutral position (the stock shifter actually has a built-in rod that snaps in to serve the same function), which will become important later, during reinstallation. |
With the three aforementioned Torx head bolts removed, the mount/linkage mechanism comes out. In reality, the shifter can stay bolted to this mechanism while it is taken out, but we "removed it for clarity" (ahem, we didn't realize this until we were already done). | 
The GM service manual has its own method of removing the rear subframe and transaxle, but it involves unnecessary steps that seemingly serve only to waste time and increase frustration. Therefore, we're calling in longtime friend (and 9-second Z06 owner), George Benson, to show us the "real" way to do it. As you'll see, his method avoids apparently asinine directions like disconnecting ball joints, removing the transverse leaf spring, and separating the transaxle from the subframe. Start by removing the rear wheels and disconnecting the upper A-arm from the frame via two 18mm bolts. |