Properly Diagnose a 722.6 Shudder in Vehicles with MDS System Engines

2007年闪避充电器配备了5.7L V8发动机和722.6传播被带到了一个传输商店。在访问时，车辆在里程表上有超过88k英里。客户告诉服务作家，车辆以前去过四家不同的维修店，试图消除降档颤抖和冷摊位。技术人员道路测试车辆并将条件描述为振动，因为它在停止时振动 - 由于它是东北的2月 - 冷失势条件也很快验证。

这家商店非常熟悉海岸颤抖状态。通过将活塞返回弹簧添加到转换器中的TCC活塞，它们已经固定了几十个带有相同的颤抖。服务作家相当有信心地将返回弹簧添加到转换器将解决条件，但选择由于车辆的高里程而选择出售重建传输和变矩器组合。bob游戏怎么下载

传输重建常规。在转换器离合器上发现暗磨损图案加强了离合器拖动的想法。当变速器和转换器重建完成并重新安装时，车辆被道路测试。技术人员发现冷摊位状况不再存在，但颤抖仍然存在。

很多第二猜测开始。耶鲁大学管理学院e research found that the previous four repair shops had focused on engine performance as a possible cause. One shop even had discovered that the condition could be eliminated by placing the shifter into the auto-stick (manual shift) mode. The same shop also discovered that the vehicle was equipped with a multi-cylinder displacement system (MDS).

The MDS system was introduced by Chrysler in 2004 and functions like the Mercedes Benz Active Cylinder Control, General Motors Active Fuel Management and Honda’s Variable Cylinder Management. In short, the MDS system deactivates four of the V8 cylinders during closed throttle operation or at steady speeds — including coastdown — and the system is not active when the shifter is in auto-stick mode. Unfortunately, the shop was not able to complete the repair circle because they got hung up on the fact that the system was functioning properly.

2014年，ATSG发布了一个关于这种情况的优秀公告（14-W22）。除了解释关注自动棒模式中的换档器时如何消失，公告还继承了电子调制转换器离合器策略（EMCC）在自动粘液模式下的活动。这意味着当TCC未被锁定时，不会感觉到这种情况。由在四个汽缸上运行的V8发动机产生的正常振动由锁定的变矩器转印，但是由发动机支架与乘客舱隔离。bob游戏怎么下载随着时间的推移，发动机安装到安全杆接触安装座的底部的点，允许驾驶员注意到振动。当坐骑在一起时，很难看到问题（图1）。

图1

When the mount is in the vehicle, the sag is even more difficult to see. It takes a high intensity light and a mirror to make detection possible. When the mount is separated, you can see witness marks where the safety rod contacted the base plate (图2）。

图2

当您查看安装座的基板时，您可以看到安全杆损坏了橡胶垫（图3.）。当移除焊盘时暴露金属到金属触点（图4.）。

图3.	图4.

When diagnosing a shudder condition on a vehicle equipped with a 722.6 transmission and an engine with a MDS system, always qualify the shudder by placing the shifter into the auto-stick mode. Don’t forget that the mount does not have to be separated or broken to cause the shudder condition.