Consolidated Vehicle Converters
Issue link: http://read.uberflip.com/i/1376224
CONSOLIDATED VEHICLE CONVERTERS QUALITY • SERVICE • SATISFACTION Expect the Best 127 temperatures of 210ºF+ can also lead to a costly transmission failure over time. Higher than normal temperatures can be attributed to cooler restrictions, internal leaks and failing torque converters. a. **Notice** The 2014-Up 6 speeds are equipped with a transmission bypass, also known as a thermostat. These assemblies will not allow full cooler flow until the transmission reaches around 160ºF. This has created overheat scenarios. The transmission tech support groups and the aftermarket have some good alternatives. There have been instances of a 25-35°F decrease in operating temperature just by using some of the products available from them. 3. Fluid – The type of transmission fluid used in the 6 speeds can affect overall performance and longevity of the rebuild. There are several instances of torque converter chatter, shudder, and flare shifts; leading to failure with "UNIVERSAL" fluid types, even when premium additives were used. A good quality Dexron VI fluid should be used. ACDelco 10-9395 fluid can be purchased from the dealer. 4. TCC Performance Issues – Many 6 speed transmissions can experience premature torque converter failure shortly after rebuild. It is easy to play the blame game, but essentially the 6 speed torque converter has A LOT working against it. a. The 6L80 uses lockup functions in 4th, 5th, and 6th gear, so it's likely that this transmission will spend about half of its life in lockup. b. Cylinder deactivation (common on GM vehicles 2007-Up) can be another culprit to the problem. Not only is the transmission locking up, but the engine is cutting off fuel to half of the cylinders at highway cruising speeds to achieve a very small increase in gas mileage. This is commonly when the infamous chugging/cycling in lockup can be felt. In cases where a "tune" is going to be installed, this is the first thing you to consider programming out. c. Excessive slippage is another issue that has been a problem since as far back in 1995, long before the GM 6 speeds. The computer will purposely slip the torque converter clutch so that the driver does not feel the lockup clutch engage/disengage. This could shorten the life of the torque converter and transmission. The older 4 speed versions of PWM (Pulse Width Modulation) and EC3 (Continuous Slip) were very easily eliminated or modified; but that is much more difficult to do with today's 6 speed units. 5. TCC Performance Fixes – There are many ways to correct TCC issues in the GM 6 speeds, and here are several ways that have can be effective depending on the customer's application. a. The aftermarket has a variety of drop in and oversized fixes for the TCC regulator valve. However, because of DOD (Displacement On Demand), you will have some cases where this will not completely fix your issue. b. Consider using an aftermarket kit that contains a drop-in aftermarket TCC Regulator Valve. It normally creates a smooth lockup transition throughout the lockup range. It works great on vehicles with factory tuning that will retain the GM cylinder deactivation programming; However, there are some cases where this will not completely fix the issue. c. Aftermarket tuning is another great option, but be advised it is not easy. It takes an experienced tuner on a 6 speed to correct baseline issues without actually damaging the transmission in the process. In cases where a tune is your answer, keep it simple. Eliminating the DOD, raising the speed for lockup engagements and slipping in MOST cases will reduce opportunity for a shudder almost instantly. e. Bushings are another issue that must be addressed. The factory bushings take a lot of abuse. Leaking front and rear stator bushings can also cause many TCC issues. There have been cases where the builder did not replace the bushings at all, or installed poor quality bushings that could cause a comeback in only a few months. Both can directly lead to issues with lockup. Consider replacing all bushings during a build. f. Pressure can play a key factor with any transmission, especially the newer 6 speeds. These units are prone to pressure regulator failures which can cause an extreme high pressure mode (285psi+). There are instances where pressure spikes of up to 500psi have occurred when this issue happens. These extreme pressure conditions cannot only physically break internal parts, but it's been known to also cause harsh lockup engagements/disengagements; which can lead to cracked piston and damper assemblies internally within the torque converter. There are several fixes in the aftermarket. Vacuum testing the PR valve after installation is always recommended. If the drop-in valve does not pass a vacuum check, then consider reaming and installing an oversize valve. Recommendation is to pull at least 18 inches of vacuum with the drop-in valve and 22-25 inches when using the oversize valve solution. g. Pump failures are a very large culprit on the 6 speeds. Most of the time the pump either needs